| Author |
Message |
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21507
Location: Oklahoma City
|
 Posted: Wed Dec 07, 2016 3:22 pm Post subject: Master cylinders: modifications, alternate types, trunk mounted |
 |
|
So I am starting a thread for this so I do not forget to.
Because we started talking about it elsewhere...most specifically in the "power assist brakes" thread...and we talked alot....I am going to reference the thread here http://www.thesamba.com/vw/forum/viewtopic.php?t=661228...instead of pulling material back and forth.
I am starting this now...because as I get the last of the undercoating and welding done front end...shortly before undercoating and reinstalling all of the front new front end....I also have reroute the hard brake lines before the gas tank goes in...if I am going to do this mod. So...I am working out the geometry now.
The problem set:
1. moving the master cylinders (just brake for most but clutch and brake for me) to the trunk...mounting plate and exact location
2. Making a proper pedal linkage for the pedal cluster...geometry and materials
3. Brake fluid reservoir...modify and reuse original...or....use an new ATE unit from a Volvo for brake and the original or a type 3 model just to feed the clutch master.
4. Fluid lines and brake light switch wires. The purist version is to not destroy anything original...
A. but to use couplings and run the hard lines from their original locations under the dash into the trunk, including plug in connectors to the brake light switch plugs and run extension harnesses into the trunk....meaning if I ever wanted to change back...just move the cylinders back under the dash and bolt them up......or....
B. completely new hard lines running from the cylinders in the trunk, through three new holes...down the firewall to meet up with the original front and rear brake feeder lines outside of the cabin.
I hope to have the actual pedal and lever geometry worked out here by a little after Christmas.
In the other thread..someone mentioned the worry that connecting the pedals to a pivot rod or disc in the middle will have arc issues....and I could see that in my head...but did not know if it was significant.
In short...it is significant. The original design allows for some misalignment in the direct connection between the pedal top and pushrod and the piston...like this:
In these three cross section images...you see pedal up..piston at top of bore and the rod angle down close to the lower edge of the taper or the wall in the bore.
Not all piston inner bores are tapered...many are just oversized...and with the end of the pushrod being ground into a ball end...its the same difference. The undersized rod is able to change angle.
In the middle image...the rod is nearly horizontal or may even be high and be near the top of the taper inb the piston bore...it could be either.I have not dissected the actual geometric placement of pedal to cylinder...yet.
In image #3...you see its back down along the lower taper as the pivot rotates backwards past the 12:00 position.
So...this works because the difference between rod diameter and piston inner bore diameter and the ball end to the pushrod.
We do not have that luxury when the clevis in the top of the pedal is driving a pivot transfer bar like I was talking about in the other thread.
HOWEVER....as long as the pushrod is ...DOUBLE JOINTED...meaning a clevis pin in the top of the pedal and a clevis pin where it mounts to the transfer bar to transfer pedal motion via a pivot to the cylinders now in the trunk...it will work perfectly. It will simply mean making a short pushrod between the clevis at the top of the pedal and the transfer bar and spacing the transfer bar farther rearward.
This is much like the difference between a swing axle and IRS rear end. 
More to come. Ray |
|
| Back to top |
|
 |
titan3c
Samba Member
Joined: February 16, 2012
Posts: 568
Location: Coweta, Oklahoma
|
| Posted: Thu Dec 08, 2016 2:03 pm Post subject: Re: Project mod: moving master cylinders to trunk modifcation |
|
|
| OK, I get it. Looking forward to the rest of this. Bob |
|
| Back to top |
|
|
jaxdream
Samba Member
Joined: August 12, 2014
Posts: 31
Location: North Central Tennessee
|
| Posted: Fri Dec 09, 2016 11:44 am Post subject: Re: Project mod: moving master cylinders to trunk modifcation |
|
|
Ray , you might look at some of the 911 later brake booster and pedal geometry . Porsche setup the booster / MC in a sideways fashion to get the braking effect with linage coming from the floor mounted pedal assembly as usual with a transfer rod and pivot linkage to achieve what you may be looking for . It may be worth a look / some your time to study them.
Jack |
|
| Back to top |
|
|
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21507
Location: Oklahoma City
|
| Posted: Fri Dec 09, 2016 1:10 pm Post subject: Re: Project mod: moving master cylinders to trunk modifcation |
|
|
| jaxdream wrote: |
Ray , you might look at some of the 911 later brake booster and pedal geometry . Porsche setup the booster / MC in a sideways fashion to get the braking effect with linage coming from the floor mounted pedal assembly as usual with a transfer rod and pivot linkage to achieve what you may be looking for . It may be worth a look / some your time to study them.
Jack |
Thank you! Yes...I have looked at the 911 set up a little bit over the years. There are some similarities. The problem with the 411/412 is room under the dash is just about 0. Room in the trunk is plenty but its roughly 5" higher up in plane.
This is actually an easy problem to solve...and VW did it when they put the power brake booster and MC in the trunk.
If you look in the link in that other thread...you can see what they did. Similar to the 911...they have a bell crank and pivot going to an idler shaft that moves the motion up onto an even plane with the master cylinder.
Its a relay lever. It works perfect....they should have simply put all the brakes in the trunk on all models.
The two big problems that require this modification in my opinion are the fact that
1. The 411/412 master cylinder is unique to the car, very hard to find. Few options.
2. When it fails...and it always will...it leaks fluid all over the carpet, steering column, wires and relays.
Moving the master cylinder to the trunk is actually a pretty easy exercise. In my case since I have a four speed....I am moving both the clutch and brake ,aster to the trunk....which makes it a little more work but no big deal.
The first object has been simply to decide what type of bracket and clevis arrangement is the simplest to make and is robust and hast he correct geometry.
You have to be a little careful with this. If you want to keep the stock pedal throw...the length ratio on each side of the pivot/relay bar must be be kept 1:1. Or....if you want the pedal stroke to be shorter I can put more length on the MC side of the pivot bar. It will also make pedal effort slightly higher if I do that.
Here is a better view of what I have planned
From the side...this is looking from drivers side...a simple 1:1 pivot bar system with an adjustable clevis pushrod between pedal and pivot bar. An adjustable clevis pushrod at the top of the pivot bar driving the master cylinder. The "A-frame" mounts are symple pices of 3/8" or 1/2" plate.
The pivot cross shaft is non-rotating. The pivot bar(s) will have bushings in them and be held in place tight with spacers and spring washers...just like factory.
Here is a view of that from the drivers side of the pedals. So since on my existing pedal cluster there is a clutch master cylinder on the left and a brake master on the right....I will have an outboard pivot bar for each one.
In reality the green clevis pins at the top really only need to be about 2.5" long maximum with about 1/2" of each one actually having the yoke and pushrod on the end. I will probably make them from 14mm diameter, long clevis pins and also add an outer bushing for strength/mass.
You can buy SAE grooved clevis pins in grade 8 and class 10.9.
Ray |
|
| Back to top |
|
|
jaxdream
Samba Member
Joined: August 12, 2014
Posts: 31
Location: North Central Tennessee
|
| Posted: Sat Dec 10, 2016 10:06 am Post subject: Re: Project mod: moving master cylinders to trunk modifcation |
|
|
You Do do your homework Ray , that is one of the things I admire about you  . My hat's off to you on your project .
Jack |
|
| Back to top |
|
|
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21507
Location: Oklahoma City
|
| Posted: Sat Dec 10, 2016 10:32 am Post subject: Re: Project mod: moving master cylinders to trunk modifcation |
|
|
| jaxdream wrote: |
You Do do your homework Ray , that is one of the things I admire about you . My hat's off to you on your project .
Jack |
Thank you sir! Ray |
|
| Back to top |
|
|
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21507
Location: Oklahoma City
|
| Posted: Sat Dec 10, 2016 1:55 pm Post subject: Re: Project mod: moving master cylinders to trunk modifcation |
|
|
A short update:
Its actually going to be a little while before I get to actual fabricating. Lots of things in the way right now....But since others tend to forge ahead on parallel projects, I wanted to throw in some important discussion points for the lucky ones that get ahead of me.
1. The openings through the fire wall into the trunk:
From the original discussion and "thinking out loud" sketches that were in the thread the link takes you to....there are some issues. If you look in the trunk under the trunk liner, just a bit to the right of the master cylinder reservoir...and down at the joint of the vertical firewall and the horizontal shelf...you will see a stamped indentation in the chassis where the hole for the pushrod for power brake unit installation would have been stamped.
Bear in mind...from the pictures in the other thread....since the factory set up for power brake....used a relay lever assembly that was centered in the "window" in the pedal cluster....this body hole indentation is aligned on the centerline with the pedal cluster.
So...bringing the clevis pin and pushrod attached to the pivot bar... inward to run down the centerline....as I show in my sketches above.... would make using that indentation to install the hole...totally doable.
What I do not know yet: Since I also have a clutch cylinder I would like to move out into the trunk....I do not yet know if there is enough space in the existing hole opening size...to allow two pushrods side by side to go through.
It will already require some careful spacing and installation for the master cylinders to use both clutch and brake pushrods side by side... like this:
2. The hardware: DO NOT repeat DO NOT...use shoulder bolts. While it seems such a simple and clean way to assemble this linkage...there is a reason the factory did not use precision ground shoulder bolts.
I found this out...almost the hard way back in the late 90's .i was trying to clean up slop in the bushings for my brake pedal. In taking the pushrod linkage apart...it was an absolute BITCH to remove and install the "C" clip on the end of the clevis pin. Lots of cursing and losing the clip.
So I decided to put in a shoulder bolt with a longer threaded shank that went through the pedal and had a nut on lock washer on the back. It barely fit...worked fine.....for about a week. It snapped off clean backing out of the driveway. I figured it was just a bad shoulder bolt. Replaced it...and it happened again.
This issue is that the hole the threads go into...must be PERFECTLY parallel and the flange area between threaded section and the ground bearing area must be perfectly perpendicular and seated on the area the shoulder bolt tightens to....or it does not Transfer load...and the threaded section is a necked down weak point in cross section.
Shoulder bolts when perfectly seated...can handle considerable side load....however...they cannot handle shock loading during that side load.....like when you slam on your brakes. Its not what they are designed for.
A clevis pin....is just basically a solid hardened bar or rod with a head on one end or an e-clip in place of a head. It can handle all sorts of side load and shock. It may distort...and get chewed up...but will not BREAK. And they are cheaper and easier to replace.
More to come. Ray |
|
| Back to top |
|
|
titan3c
Samba Member
Joined: February 16, 2012
Posts: 568
Location: Coweta, Oklahoma
|
| Posted: Sun Mar 26, 2017 5:48 am Post subject: Re: Project mod: moving master cylinders to trunk modifcation |
|
|
| I've been pondering over this mod., and working on some ideas, and have a question. Is there any other Master Cylinder that will work on a type 4? I think I have read sometime back that a type 3 cylinder would work. Also I'm wondering if a late model type 1 would work. The physical size doesn't bother me so much. It's the "innards", because I have it in my head that the type 4 is peculiar to all other cylinders for specific reasons. The type 1 cylinder looks almost the same externally,(except for mounting),but I doubt if the same internally. Bob |
|
| Back to top |
|
|
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21507
Location: Oklahoma City
|
| Posted: Sun Mar 26, 2017 8:44 am Post subject: Re: Project mod: moving master cylinders to trunk modifcation |
|
|
| titan3c wrote: |
| I've been pondering over this mod., and working on some ideas, and have a question. Is there any other Master Cylinder that will work on a type 4? I think I have read sometime back that a type 3 cylinder would work. Also I'm wondering if a late model type 1 would work. The physical size doesn't bother me so much. It's the "innards", because I have it in my head that the type 4 is peculiar to all other cylinders for specific reasons. The type 1 cylinder looks almost the same externally,(except for mounting),but I doubt if the same internally. Bob |
Some of this compatibility I am working through in my other thread about hydraulics parts restoration.
So.....in light of what I am working on.....it was time to update this thread anyway.
Depending on years of course....varying from 1967 to 1977 and it varies between models.....type 1 standard beetle, ghia, thing and type 3 master cylinders.....use the same piston rebuild kit.
This pretty much corresponds to the range of cars that moved from single circuit to dual circuit as well.
This is what both Cip1 and pretty much Rockauto list.....and to a large extent....I believe this is correct......at least for the rebuild piston kit.
But there are some issues with this thought process in the 1971 to 1974 range according to both the "without guesswork" book and also from my experience.....which is mostly to do I am pretty sure with Superbeetle and possibly beetle convertible.
The problem is that the actual cylinder castings have some variations that make them different both in placement and number of openings for brake light switches and for output lines to the wheels.
The only items that makes one cylinder or another able to use the same piston kit.....is the location of the fluid input ports from the reservoir and the total inside length and diameter of the bore. The fluid inlet ports cannot be blocked by the piston cups or piston heads.
But.....that does not mean that a given master cylinder casting for a given application has to have the exact same inside bore length ....because the pistons have springs that can compress to fit inside......and that changes not only the actual stroke length of a circuit....but the spring preload......which changes the brake bias from front to rear. Also the stop screw in the side of the cylinder is in different places in different castings....which gives different total length and compression to the piston set.
With me so far?
For instance.....installed in my car right now.....is a German FAG cylinder from either a Superbeetle or a standard beetle. I will need to check my books to be sure what I used.
I was at the end of my rope years ago in easily rebuildable type 4 cores....could not get anything at the moment other than really crappy Brazilian type 3 MCs from my local VW parts house in Dallas......so I bought several of what would fit.....piston bore and length wise.....and set out to modify it and install it......  .....holy crap what a hair curling mess that was.
Over most of a year I think...maybe more.....I wrote about it earlier maybe even in this thread....I tried several MCs from other VW cars.
The problem is.....and this is listed in the "without guesswork book".....at least between 1971 and 1974.....some of the dual circuit beetles use a 17.5mm front circuit stroke and an 11.5mm rear circuit stroke.
The type 3 for all years.....uses a 15mm front and a 15mm rear stroke length
The type 4 for all years.....uses a 15mm front and a 15mm rear stroke length
So....I can tell you that outside of exact placement of the piston stop screw for the inner piston set (which I do not know if its different or not because I no longer have a type 3 cylinder laying around to measure and do not have a record of what it was).....and outside of line placement and inlet port locations.....which are different on the type 3 and type 4 cylinders.......the type 3 MC is identical to the type 4 in stroke length and piston diameter.
That difference in stroke lengths of the beetle cylinder....was a HUGE problem. To increase the front stroke length I had to grind off the tail of the inner piston by about 3mm.
So....since I have a beetle cylinder in my car already.....there is obviously another way to put different cylinders in the car under the dash that I have not mentioned yet .
Yes....its a lot easier than the modification of moving the MC's to the trunk.....but it permanently changes the pedal cluster.....requires welding....and still does not get the MCs out from under the dash.
But.....as I have been thinking about the modification for moving the MC to the trunk.....which I now know can be done.....I have pretty much worked it out........moving the MC to the trunk.....is a BIG modification. Not huge.....but big. As you can see it reqyires making cross over levers, pushrods, a pivot, a moujtiny plate.....and rerouting and bending new brake lines.
I have so many things to do to this car......that I just am not sure I can invest that kind of time.
So I have thought about what the benefits are that this modification would give....and what I NEED.....and why. These are:
1. I need a permanent, high quality, easy to get and pay for..... supply of master cylinders for this car. If quality MCs for type 4 were readily available....I would never have thought about moving the MC to the trunk.....I would have simply set about solving the other issue of the stock type 4 MC.
2. I would really like to get the MC out from under the dash. Its not that its just hard to reach....I can work around that.....its that when it craps out and leaks.....or when you have to remove it.....it leaks fluid all over wiring, the fuel pump relay, the pedal cluster and the floor and carpet.
But.....if I had a ready supply of type 4 specific master cylinders.....or any suitable MC that would bolt up in the original positiin under the dash......would solve that last problem by making a snap in or bolt in "drip tray" out of thin stainless or polypropylene.....with kind of a reservoir area......to catch leaks and any fluid that spills while working on the MC.
I am working on that now as well.
So.....as you can see from my other thread about restoration of cylinders......I am thinking about keeping the cylinder under the dash....either by making sure I have a permanent supply of type 4 cylinders or by simply keeping a type 3/beetle style cylinder under the dash.
I will post a sketch and a photo if I can get one shortly.....of how the beetle/type 3 cylinder is installed in my pedal cluster.
It is an option....but at the moment....without doing some restoration work to the pedal cluster.....I cannot move back to a type 4 specific MC. Ray |
|
| Back to top |
|
|
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21507
Location: Oklahoma City
|
| Posted: Sun Mar 26, 2017 12:17 pm Post subject: Re: Project mod: moving master cylinders to trunk modifcation |
|
|
Update for Sunday 3-26-2017
To be more succinct in answer the question from titan3c...or "Rocketman" as I always think when I see your screen name 
No...there are no other master cylinders that I know of...in this size and stroke that have the "side winder" style bolt mounting pattern.
The closest I "think" I have seen...is that I thought at one time there were some Audi or even early Vanagon that had non-power brake master cylinders with the MC under the dash on the pedal cluster.
On the Vanagon...the complete CLUTCH master cylinder can be bolted into the type 4 without too much trouble...by making a simple angle iron bracket. But...you will have to re-bend the fluid outlet line to mate up because the fluid outlet is on the bottom instead of the side.
My last lengthy response was in regard to what "could" work ...in the hydraulic, stroke length and functionality aspect.
That being said...here is what is in my car now:
Its a little hard to see whats going on....this is the view from the passenger floorboard.
A little closer
With some captions.....you can see that I welded an angle iron plate to the pedal cluster.
A closer view
You can also see that the mounting plate now obstructs the original master cylinder mounting hole.
The problem with this is....and I will show you a little further down....is that the MC had to be canted with the mounting ears at an angle on an axis between say...10 and 4 o'clock to both fit...and have correct fluid inlet and outlet lines in the right location.
What you cannot see...is that the upper mounting ear on the MC...has been sliced off...and the MC is mounted with one bolt. To keep it stable....I did this.....
..yes...that is a socket clamped to the end of the MC to give it a "foot" to bear against the pedal cluster. I wanted to weld on a foot...but the mig welder I was using at work ...was out of gas and we had no flux core...and time was critical as this was my daily driver
The truly correct and elegant way to have done this....was to have cut a notch or access hole/notch in the pedal cluster....weld the plate onto the inside of the pedal cluster sticking through on both sides of the pedal cluster.
In this way...the other ear of the MC would have stuck through to just the inside and bolted to the angle iron plate.
Or this adapter plate could possibly have bolted onto the MC without welding. I could have also moved the MC slightly more forward to clear the original MC mounting hole....and then re-calculate and readjust the pushrod length to keep pedal stroke normal.
The most elegant way would have been to make a flat plate bracket that bolts to the pedal cluster in the original position as the stock type 4 MC...with the angle iron bracket welded to the forward end.
This would cause the new MC to be about 1.5" off centerline from the pedal pushrod...toward the passenger side. What would need to be done...is to insert an extended clevis pin and bushing set up...to move the pedal pushrod 1.5" to the right.
At the time I did this...I was lacking in tooling and time to test and experiment...or that is what I would have done.
So...the choices moving forward in my head....are either:
1. to have an original type 4 master cylinder ...sleeved with stainless or nickle plate in the bore.....I can have the sleeve done for about $150-ish.....and I will soon be set up to nickel plate (not just for the MC but for caliper pistons and the regulator valve...so it may be worth the cost).....both of which will insure that well cared for....a single original type 4 MC....can last forever with just the occasional replacement of seals and flap valves scavenged from any NEW cylinder from type 1 or 3 vehicle kits.
This has merit...because nothing else changes.
2. Make a bracket adapter to mount a type 3 cylinder under the dash.
This has merit...in the respect that its simple. But....it also has less merit...in the fact that good quality master cylinders ...with the exact same casting shape and fit...are getting harder to find every day.
MC quality aside....this is the problem I was already finding in 2001 when I was doing this mod. Brazilian made Varga cylinders for type 3...had some oddities to the two bolt flange ear...that would cause no issues with type 3 or type 1 fit....but would change the fit or make it difficult on the bracket I was thinking of making.
Like this:
This is a crude sketch of the pedal cluster with an L-bracket installed and the master cylinder moved about 1.5" to the right. You will have to make a pretty stout clevis pin for the top of the pedal...to make sure that side loading in a hard braking situation...does not snap the pin. Ray |
|
| Back to top |
|
|
titan3c
Samba Member
Joined: February 16, 2012
Posts: 568
Location: Coweta, Oklahoma
|
| Posted: Sun Mar 26, 2017 12:54 pm Post subject: Re: Project mod: moving master cylinders to trunk modifcation |
|
|
Ha ha, "Rocketman" is funny. I just threw that in one day as I was logging in on this web site. The reason---long ago when I was a civil service employee I was assigned to the Atlas, Titan 1, and Titan 2 activation programs(during the missile gap with Russia), and then to the development of the Titan 3c at Vandenberg AFB----which was the forerunner of the NASA space launch system. Now you know where "Titan 3c comes from" I like rocketman better.
I'm on the same path with you on the mod stuff. But I wasn't sure if the Type 3 cylinder would work technically on the Type 4. Since I'm just now getting around to removing the MC on my car these thoughts are surfacing, and I drew up an adapter identical to what you did. BTW I bought one of the NOS master cylinders from Vermeer vw parts in Ohio. He must have inventory of these. It only cost $60.00, and I mentioned the doubts about the problems with NOS master cylinders in conversation with Brad at Vermeer motors(I may have the company name spelled wrong). He knew exactly what I was talking about. His comment was "I have sold over 200 of these, and had only one come back because of that problem, and if I had a problem he would give me another one at no cost." He has both ATE and FAG.
I plan to install this one while rebuilding the one I'm removing from the car now. That will give me time for testing the NOS cylinder. Bob---oops "Rocketman" |
|
| Back to top |
|
|
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21507
Location: Oklahoma City
|
| Posted: Sun Mar 26, 2017 2:06 pm Post subject: Re: Project mod: moving master cylinders to trunk modifcation |
|
|
| titan3c wrote: |
Ha ha, "Rocketman" is funny. I just threw that in one day as I was logging in on this web site. The reason---long ago when I was a civil service employee I was assigned to the Atlas, Titan 1, and Titan 2 activation programs(during the missile gap with Russia), and then to the development of the Titan 3c at Vandenberg AFB----which was the forerunner of the NASA space launch system. Now you know where "Titan 3c comes from" I like rocketman better.
I'm on the same path with you on the mod stuff. But I wasn't sure if the Type 3 cylinder would work technically on the Type 4. Since I'm just now getting around to removing the MC on my car these thoughts are surfacing, and I drew up an adapter identical to what you did. BTW I bought one of the NOS master cylinders from Vermeer vw parts in Ohio. He must have inventory of these. It only cost $60.00, and I mentioned the doubts about the problems with NOS master cylinders in conversation with Brad at Vermeer motors(I may have the company name spelled wrong). He knew exactly what I was talking about. His comment was "I have sold over 200 of these, and had only one come back because of that problem, and if I had a problem he would give me another one at no cost." He has both ATE and FAG.
I plan to install this one while rebuilding the one I'm removing from the car now. That will give me time for testing the NOS cylinder. Bob---oops "Rocketman" |
Sold over 200 of the type 4 cylinder?.....yes maybe over 15-20 years.....and each year they are getting older. You would be hard pressed in the past decade to find more than about 250-300 of these cars running on this continent....and rarely do you find one with an NOS cylinder recently installed.
Selling over 200 NOS VW cylinders of all types.....yes I believe that. But no complaints......I do not believe that at all.....not to him anyway. Not many who understand the risks go back at a seller of NOS parts.
There are numerous threads just here in the samba of NOS brake failures due to age. They are not designed to sit on the shelf. All rubber has issues with age. The problem with NOS brake master cylinders and wheel cylinders and shocks.......is that because they are NOS....you pay to much....and the seals all generally work out of the box. But.....they usually do not last long once they get into brake fluid. So you get a few months on a daily driver....or a year or two on something seldom driven.....and then you get fluid bypass.
That being said.... $60 is not bad....but not great. Its about half the cost of a sleeve job.
And its great that he understands and warrants the part. That....I would not ro....simply because ai know how the rubber ages......and the risk is that in a year or two you can be back at it looking for a replacement.....and all the pain in the neck of replacing it.
Sounds like a good guy to do business with either way. I saw his add in the classifieds.
Other issues with rebuilding I will get to in the other thread.....are the fact that these cylinders are not plated inside. Even water vapor from air inside can cause corrosion on an off the shelf cylinder. Either way....the damage eituer from wet brake fluid etc......is pitting in the cylinder wall.
Unless its horrendous......you can hone it out in minutes. But......the cylinder will then usually be out of tolerance.
I have found that even new cylinders are many times at the extreme end of the required tolerance.
The "spec" for the bore is 19.05mm. That's exactly 0.75". The pistons are generally very accurate.....they are die cast zinc. They are 0.748" or 18.99mm diameter. So the minimum bore to piston tolerance when new is .002".
But....I find new bores that are .003" to .0035" all the time. The maximum tolerance is .004".
After honing to get rid of pits you can easily be at .005" to .006". This is the issue ai hwvr found with cheap remanned cylinders. Within a year or so of daily driving when the piston seals start to harden up a bit.....they bypass fluid.
So to rebuild.....the best way to go would be to plate the bore. Many modern master cylinders are coming with plated bores. Ray |
|
| Back to top |
|
|
titan3c
Samba Member
Joined: February 16, 2012
Posts: 568
Location: Coweta, Oklahoma
|
| Posted: Sun Mar 26, 2017 4:19 pm Post subject: Re: Project mod: moving master cylinders to trunk modifcation |
|
|
| Yep I had the same thoughts, in fact I wondered where did he find 200 type 4 owners, but I didn't ask him. Just figured he sold most of them before the 90's. Also my thought is hoping this nos mc lasts while I'm researching as you on a more permanent fix. I've got my eyes open for a salvage pedal bracket so I can bench work on a prototype for the trunk. I don't want to remove mine to play around with. I've found a couple of salvage brackets, but they want too much for them. After reading your comments about the type 3 master cylinder that appears to me to be the one to work on for the trunk mod. BTW I said my sketch for under the dash was just like yours. Well not exactly, but real close. Bob |
|
| Back to top |
|
|
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21507
Location: Oklahoma City
|
| Posted: Sun Mar 26, 2017 6:46 pm Post subject: Re: Project mod: moving master cylinders to trunk modifcation |
|
|
| titan3c wrote: |
| Yep I had the same thoughts, in fact I wondered where did he find 200 type 4 owners, but I didn't ask him. Just figured he sold most of them before the 90's. Also my thought is hoping this nos mc lasts while I'm researching as you on a more permanent fix. I've got my eyes open for a salvage pedal bracket so I can bench work on a prototype for the trunk. I don't want to remove mine to play around with. I've found a couple of salvage brackets, but they want too much for them. After reading your comments about the type 3 master cylinder that appears to me to be the one to work on for the trunk mod. BTW I said my sketch for under the dash was just like yours. Well not exactly, but real close. Bob |
we are working along the exact lines! I am also looking for a pedal bracket for mods and mockups.....but also think what is out there is just too expensive.
But since mine is not running.....its probably just about time to take it out and have it be the guinea pig for pictures here.
I am very close.....to not doing the "move to the trunk mod".....simply because it puts a lot more stuff under the dash. Its already tight down there. I have been working on mockimg up the rods and pivots just to see the alignment.
If i had type 4 cylinders with sleeved bores.....I would just fashion a drip tray and be done with it.
But....that does not fix the problem for the rest of the community at large.
The bracket and type 3 cylinder under the dash would be the least mods and the least invasive. The brake light wires would plug right on.....and the brake lines can stretch a bit to the right....all is good.
What I really need to do.....is buy.....a type 3 cylinder or borrow one that is shot from someone. A good ATE or FAG cylinder. The things I need to measure are the inner circuit stop bolt spacing....that little bolt with the copper washer that goes through the side of the cylinder on dual circuit MCs......and the thickness/length of the steel cup that is the bottom seat on each primary circuit spring. That steel cup is the stroke stop for the primary front circuit.
The leg or pin on the inner piston is the stop for the inner piston.
On the other hand.....I can take original type 4 cylinders......caustic strip them to get rid of every spec of rust.....then hone them to get rid of all pits inside.....then acid pickle them, degrease.....put them on a jig......and plate the bores with electroless nickle plate. That will bring the bores back in spec....and as long as you do not abuse them with picks etc.....they will never rust....and be smooth as glass.
Electroless is nice...because it takes no current and electrodes. The deal is.....clean, clean, clean.....smooth the surface by lapping.....then heat the nickel solution to 200F....run a circulating pump in the bore....mask the outside off.....and as long as you have calculated the nickel load for the soup correctly and keep the temp stable....I can plate .002"+ of nickel in the bore.
It would then be worth it to plate the outside with zinc and chromate it so it will never rust.
Once I get set up for plating....going to do it anyway for work on caliper pistons and other parts.....I would be happy to plate cylinders for the type 4 community.
See......here is the frustrating and sad fact......master cylinders NEVER, EVER "wear" out
The standard bore tolerance between piston and bore.....is between .002" and .0035".....the pistons NEVER touch the bore.
The rubber cups never wear the bore. Unless you get grit in the back of the MC from not running a boot.....or do not have the dust strainer insert in your brake fluid reservoir....you will never groove or score the bore.
The pistons....on original ATE and FAG.....were solid zinc. They are heavy as lead! 2.643 times heavier than aluminum brake pistons to be exact.
Becasue they are zinc.....they do not rust. However....when exposed to moisture in the fluid....they create "white rust" as they corrode. So....from what I can tell.....they were either activated by an acid or caustic dip....and then "chromate" dipped.....or some were either tin or zinc plated. As long as the "white rust" has not screwed up the seat where the flap valve seals......the pistons will last forever.
You can also note that both ATE and FAG, Varga and others....moving into 80's.....went to aluminum pistons.
1. Because its cheaper
2. Because they do not create the sacrifical white rust....as fast
3. Because they are also usually clear anodized. The aluminum pistons can last forever.
So....if you get a good cylinder and piston set.....and you flush your brake fluid like clockwork every two years....or every 1.5 in tropical humid areas.....and then just tear it down every 4-5 years and give the pistons a quick dip in a light caustic to strip away any corrosion starting to grow.....give it a quick scotch brite pass on the bore.....and then slap in new cups and flap valves and boot from an $8 kit.........they can last forever.
The only thing that wears out master cylinders....is rust in the bore......and heavy corrosion on the pistons.......and we know both of those issues are 100% preventable by how we maintain the system.
Its kinda cool that companies like Centric.....and even Varga.....if you happen to note......on NEW....rarely on rebuilt....but NEW...master cylinders.....almost all of them come looking kind of cheesey with that yellow chromate on the outside. This is actually VERY smart.
It means they zinc plated the outside.....and probably the inside at the same time. Then passivated it with yellow zinc or some chromate. Well cared for they can last for ages. Ray |
|
| Back to top |
|
|
titan3c
Samba Member
Joined: February 16, 2012
Posts: 568
Location: Coweta, Oklahoma
|
| Posted: Mon Mar 27, 2017 4:58 am Post subject: Re: Project mod: moving master cylinders to trunk modifcation |
|
|
| Interesting, the first choice for buying a new mc was from Auto Parts Warehouse. The picture they show of the mc has that yellowish color. I wondered if that was the actual color or a picture problem. So now after what you said makes me think it was a true color. Don't know what their source is but they were out of stock, but expected replacements in about three weeks. There cost is a little higher--$94.97. I questioned them about the shelf life problems, and they told me there cylinders are new not old. Now I don't know what to make of that. Interesting that they had a Type 4 cylinder listed, and I have doubts that they will receive new cylinders. Anyhow I'm watching that to see if they do get new ones in stock. Not really interested in buying one now though. Their ad can be seen on their web site. Bob |
|
| Back to top |
|
|
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21507
Location: Oklahoma City
|
| Posted: Mon Mar 27, 2017 7:27 am Post subject: Re: Project mod: moving master cylinders to trunk modifcation |
|
|
| titan3c wrote: |
| Interesting, the first choice for buying a new mc was from Auto Parts Warehouse. The picture they show of the mc has that yellowish color. I wondered if that was the actual color or a picture problem. So now after what you said makes me think it was a true color. Don't know what their source is but they were out of stock, but expected replacements in about three weeks. There cost is a little higher--$94.97. I questioned them about the shelf life problems, and they told me there cylinders are new not old. Now I don't know what to make of that. Interesting that they had a Type 4 cylinder listed, and I have doubts that they will receive new cylinders. Anyhow I'm watching that to see if they do get new ones in stock. Not really interested in buying one now though. Their ad can be seen on their web site. Bob |
I will bet you money .....you will not receive a master cylinder from Autoparts Warehouse.
There are many companies on line like Autoparts Warehouse. More than a handful are all thr same company and all have the exact same search engine when you go on their sites.
https://www.consumeraffairs.com/online/autopartswarehouse.html
Many of these reviews are exactly like what I have experienced speaking to Autoparts warehouse and CarID.com
https://en.m.wikipedia.org/wiki/Auto_Parts_Warehouse
Autoparts warehouse is basically an online "search engine" company. Yes.....they do sell autoparts......primarily not anything more or less than what you can get from a FLAPS inventory wise. They are just like CarID.com.
They are an order fulfillment company.....not a serious parts warehouser like Rockauto.....even though they do have several warehouse locations. Its because of the issues I have had with companies like this....that I waited years to use Rockauto.
I went through the 411/412 "parts dance" with autoparts warehouse a few years back.
I just went through it recently with CarID.com.
These companies work within the Google search engine. It works like this......
You start doing concentrated searches for obscure parts.....with both keywords and part #'s....like "VW 412 brake master cylinder".
You get a few companies at the top of the Google list like "Yoyo parts".....legitimate company.....that contracts to build bulk parts.
Off to the side under "sponsored sellers"....or these can appear across the top of the page....you see short blurbs with pictures......usually Amazon, Ebay, Jeggs or Summit racing. These are all legitimate companies that either really have what you want....or something close that fits part of your search description.
Then....either at the top of the Google list or near the bottom of the page....you see listings like CarID.com or Autoparts warehouse. About half the time they may have a small box attached to their listing that says "Ad"......usually your part # or search term is contained in highlighted text in the blurg under their listing link.
What these companies are doing is using the Google bots to follow your search for auto parts. They usually do not have obscure or rare parts. They do have your part # and car listing and can pull up generic pictures from the Google image archive to fulfill your search.
The almost always say the same thing.....out of stock ....three weeks or 2 months etc.
What their system does is generate an order...after you pay.....and then somehwere in their system it starts an inventory search of all of their party vendors snd warehouses.
They will eventually get back to you and say "obsolete" and refund your money.
I went through this with several online companies all under the unbrella of their parent company "US Auto Parts Network"....shopping for type 4 brake mate4 cylinder, ball joints and transmission bearings.......nada....never got a single part....and in more than one case....had to nearly beat my refund out of them.
Yes...they are a legitimate company.....but they will say they have ANYTHING......when they usually do not. They kind of see themselves as a "parts finder".....but they can only search their own network.
However....some of these networks are keyed into rebuilding/remanned houses. The time lag..3 weeks to two months.....is sometimes because they contact one of their reman networks and ask if they have a core to rebuild.
Many times.....they are making the assumption that they will probably find a core in the system to rebuild and ....voila.....you get a part .....and in that one rare case that it happened for me with a clutch master cylinder almost 10 years ago.....it was defective.
If you can actually get a master cylinder from them I would be stunned. Ray |
|
| Back to top |
|
|
titan3c
Samba Member
Joined: February 16, 2012
Posts: 568
Location: Coweta, Oklahoma
|
| Posted: Mon Mar 27, 2017 8:50 am Post subject: Re: Project mod: moving master cylinders to trunk modifcation |
|
|
Just wondering if it would be of any benefit to paint the mc. When I was a active boat operator I used to paint my out drive with a prime of zinc/chromate, and then final in a color for outdrives called "black fathom"---I think that's what it called----anyhow that's close enough. The aircraft industry used zinc chromate on just about everything. It's dangerous to use, and hard to find for that reason.
Painting would sure make it look better and clean. But what's the benefit other than cosmetic? Bob |
|
| Back to top |
|
|
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21507
Location: Oklahoma City
|
| Posted: Mon Mar 27, 2017 12:36 pm Post subject: Re: Project mod: moving master cylinders to trunk modifcation |
|
|
| titan3c wrote: |
Just wondering if it would be of any benefit to paint the mc. When I was a active boat operator I used to paint my out drive with a prime of zinc/chromate, and then final in a color for outdrives called "black fathom"---I think that's what it called----anyhow that's close enough. The aircraft industry used zinc chromate on just about everything. It's dangerous to use, and hard to find for that reason.
Painting would sure make it look better and clean. But what's the benefit other than cosmetic? Bob |
Yes. As PMB performance notes on their site...and I totally agree with them....the best method is to zinc plate and then passivate with a chromate and then paint.
The problem with painting is that when you dribble brake fluid on it....it will destroy it.
The problem with zinc chromate over time...is that it starts getting chalky looking.....which is what its supposed to do as the zinc acts as a sacrificial corrosion anode...so that the master cylinder casting does not rust.
The best of both worlds is to zinc plate with chromate...and then paint over the zinc chromate so it never oxidizes. If you can get a good epoxy or polyester on it....quickly wiped of brake fluid may not affect it. Like...caliper paint.
Hey...tell you what...I am going to move these comments over to the the "hydraulic parts reconditioning" thread...and lets continue this there. Ray |
|
| Back to top |
|
|
titan3c
Samba Member
Joined: February 16, 2012
Posts: 568
Location: Coweta, Oklahoma
|
| Posted: Mon Apr 03, 2017 4:03 am Post subject: Re: Project mod: moving master cylinders to trunk modifcation |
|
|
| Puzzled: I noticed in the pictures of your mod mc that the pan or apron for a better word under the mc is missing. I don't think that is removable on my car. |
|
| Back to top |
|
|
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21507
Location: Oklahoma City
|
| Posted: Mon Apr 03, 2017 8:54 am Post subject: Re: Project mod: moving master cylinders to trunk modifcation |
|
|
| titan3c wrote: |
| Puzzled: I noticed in the pictures of your mod mc that the pan or apron for a better word under the mc is missing. I don't think that is removable on my car. |
Yes....a portion of it is missing. There was just no way to mock this up and make proper positioning of the MC because it was in the way.
The "minor" problem(s) of putting in a bug or even type 3 master cylinder...are that based on the location of where the two bolt flange of the master cylinder is....the master cylinder itself can extend a good bit past that mounting flange....depending on the make and model it came from.
I was running into issues with pushrod length, interference with pedal movement etc.
The top one is super beetle 71-79....which is I believe...what I have in mine right now. The bottom one is standard beetle 66-77.
So...as I have been getting at....if one is to make a bolt on bracket to allow using a beetle or type 3 cylinder under our dash.....it would be ideal...to choose a cylinder....but one...and then make the bracket to fit.
And you may need to make changes to pushrod length (cutting or grinding). At the time I was installing this....I was not willing to change certain items permanently...yet...or incur massive amounts of adjusting or risk. It was time thing.
My 412 was my daily driver and I covered a region of Texas, Oklahoma, Kansas, Arkansas, Louisiana and part of new mexico. My standard mileage was about 1000 to 1300 miles per week.....and a lot of it was in 65 mph bumper to bumper traffic.
The shield portion....was not missed....as at that time I still had mu under dash cover so it all looked fine. If I still had the piece of sheet metal I removed...I would weld it back on and grind the welds smooth.
Not a big deal but one more reason I am looking for a spare pedal cluster I can afford.
Of course...you COULD make the mounting holes in the bracket...slotted so its adjustable for different cylinder castings...but you will have to make a positive stop for it. You do not want to risk bolts coming loose and the bracket sliding around.
Ray |
|
| Back to top |
|
|
|
