TheSamba.com :: View topic - Bleeding brakes on 1967/1968 beetle chassis

Mon Jul 08, 2019 7:36 am

Brakes worked when i first had car two years ago. Installed a new master cylinder, cannot remember if chinese or Brazilian. Also installed the little units that go at each brake drum that operate the drums (forget what they are called). I am pretty sure these are made in china i got from concept 1 in calgary.

I have always had trouble bleeding brakes on beetles. Even my first car which was a 74 std beetle had same difficulty. I seem to get air in the lines. Ive of course read the manuals, youtube videos, and my dad has been helping me with attempting to bleed the air out.

At the current moment when i press the brake pedal a number of times fast and consecutively, and hold the brake pedal down, the pressure increases to a bare minimum for flat surfaces...

Bleeding brakes should be straightforward....

Any tips tricks or advice?
There are some things i may end up paying a shop to do...

Mon Jul 08, 2019 8:36 am

https://www.thesamba.com/vw/forum/album_page.php?pic_id=1798516

The one man bleeder works great, you still need to bench bleed the master or it is a real pain to get all of the air out. Buy 2 of them and do front and rear one side at a time. you can get them at pep boys or amazon.

Mon Jul 08, 2019 9:07 am

You don’t have to bench bleed in fact Bentley manuals make no reference to this and we did brake jobs for over 40 years skipping this. Rapidly pumping the pedal will make bubbles and make bleeding more difficult. With dual master cylinder start with front wheels first then back, this is per Bentley. The two man method is cheapest and again per the book works every time.

I’m sure some will pipe up with How bench bleeding is the answer, ask them how many years experience they have and why they deviate from what the people that made the car said. Does it hurt to bench bleed? No it makes about as much sense as eating a ham sandwich before you begin :D good luck do a search and find about 500 threads on bleeding the brakes, very confusing I’d follow Bentley to the letter except for the admonition to not alter push rod length but that’s a whole different topic. About the only thing we can agree on is Air is compressible but fluid is not.

I worked in a hydraulic shop building actuators for commercial airliners and we used a paste and fluid mix to assemble the dry components. I mention this because if M/C and wheel cylinders sit around they might be dry when you get them. It would be beneficial to prelube using assembly lube also you’d get to inspect the bore for proper finish, why? Because the aftermarket parts are shit now.

Mon Jul 08, 2019 9:32 am

I did bench fill the master cylinder prior to installing.

Mon Jul 08, 2019 9:39 am

Lock all of the adjusters tight before you bleed, this will rule out adjustment issues when you're bleeding and getting a "feel" for the pedal. Verify your MC pushrod/pedal stop are adjusted correctly, there should be 1mm free play at the pushrod IIRC. After bleeding you should have a rock hard pedal that moves less than an inch, then adjust the shoes properly and you're good to go.

If it has check valves in the MC outlet fittings the vacuum bleeder may not work properly and you'll need to "two man manually bleed" it.

Mon Jul 08, 2019 12:52 pm

Zundfolge1432 wrote: I worked in a hydraulic shop building actuators for commercial airliners and we used a paste and fluid mix to assemble the dry components. I mention this because if M/C and wheel cylinders sit around they might be dry when you get them. It would be beneficial to prelube using assembly lube

VW used to mention a brake assembly paste of some sort but I never found their brand anywhere. I used a generic FLAPS variety years ago when I redid the brakes from scratch. I can't say it was needed but I followed VW's instructions where I could.

Anyone got a reference, and an equivalent for today?

And is it a different product depending on whether you use DOT 3/4 or DOT5?

Mon Jul 08, 2019 2:28 pm

I just recently replaced all the brake goodies on my 70KG. Calipers, wheel cylinders, master cylinder, pads, shoes, drums, rotors and all the brake lines.

I tried the old fashioned two man method but being that the other “man” was my wife she couldn’t seem to get the hang of the whole up and down rhythm.
So I got one of these.

Bled them out in 15 minutes.

I’ve read in a few places that if you’re bleeding by pumping the pedal you should start with the longest lines ie passenger rear, driver rear, passenger front then driver front, but if you’re pulling through you should start with the shortest lines first. I don’t know how valid this advice is but it worked in my case.

Mon Jul 08, 2019 4:17 pm

For the names, it's actually kinda shameful, they're called master and slave :shock:

I bled my brkes on my 1303, after installing new calipers in front, and a new master cylinder.

First, I adjusted the rears (well,not really, as they were not changed, and was able to put it all back as needed, even the handbrake balance was right when reassembled).

From your question, I'm guessing that you're a novice to such endevours. I only say this because there some things which are easy to get wrong if it's your first time: the brake adjusters have an angled working surface, and those can be put on backwards. And all that hardware has to go right back how and where they were,there's ways of jumbling it up, believe me.

If you don't know the state of your hand brake, make sur both sides are completely free, at all times, and you can worry about that later. Adjust the brakes.

Now I used to do more cars than I do now, and I had a pressurised system, with the right cap for vw. That worked a charm, but it takes a few litres of brake fluid to make it worthwile. And those stupid reservoirs are pretty much always in a place on the car/bus, (except the early, single circuit ones) that makes access difficult and akward , and when those pressurised things spring a leak, THEY LEAK, in disasterous proportions.

I've never really been bothered to use those vacuum thingies, but they're probably pretty good. I just don't see how you can guarantee you're not pulling in air from the threads? Then you will always see litle bubbles, no?

So heres's what I use. I'ts adjustable and versatile, if you're lucky: a buddy.

So i put the car up on the lift, after installing the buddy in the front seat.

Now, you need a stepladder to check on and fill the reservoir. Damn, I forgot DOT 3 even existed, it doesn't really exist here...
You'l also need a small funnel, and because of the stingy geniuses at VW, best get a cheap plastic one, because you're going to need to deform it to work right.

If you don't have access to a lift, put it up on jackstands, unless you're a circus-level contortionist. Be carefull, there are good and bad jack stands, but a different issue. The big problem is now the buddy can get away. Don't leave ANY beer within sight.

If you're closer to the ground, you don't need the stepladder.

Put a rag, or some paper towels or whatever, around the reservoir to catch all the brake fluid you are going to spill everywhere. Brake fluid is paint kryptonite.

Then, fill the resevor to a decent level. I sure hope you've cleaned out that reservoir, it can be hard to see the level even on a clean one :lol: .

So, mop up as best you can the stuff you've spillled everywhere.

Now, i always start from the cylinder/caliper furthest away from the master cylinder. I never noticed it wasn't that in the Bentley, to be honest, but I remember Volvos and others with more complex circuits and procedures, which I follow scrupulously.

Set up your bottle or whatever you'r bleeding into: for the tube, I use the usual see-though stuff, but at the end, I have clamped a bit of tight , thick rubber tubing, where I cut off the ouside layer, making it easier to fit over the wrench. and keep a bit of fluid covering the end of the tube.

Oh! I forgot...and have have a closed wrench which you have masterfuly bent to fit, even with the wheel on. Sometimes you need to, if you can't lift thing like you'd want to.

So, in whatever order you settle on, here's the deal: the buddy must pump slowly on the pedal 3-4 times, and keep exerting pressure on the pedal. You can sometimes leave the bleeder open at first, but it can depend. If it's not going right,

Close the bleeder hen have your buddy say "go" as soon as he (her?)has pressed three times.

Then you open up the bleeder, and as son as there is no detectable movement in the see-through tube, close it again and say "go". Now your buddy knows to pump again. I do a round like that, until I get fluid And then I go around again,it's just a really quick succession of "go"s, when you've got the practice. Don't forget to regularly check the level in the reservoir, and top it up as needed. If it goes dry, you'll have to start over.

Sometimes you can cheat, and leave the bleeder full open when the buddy pumps (surprise!), and pump out a big volume of clean fluid.

By now you should have pretty bubble-free fluid coming out, and the buddy should be confirming that the pedal is hard now.

I then let it sit a while, overnight, if I can, and then do it again. Shoud no longer be able to see the slightest tiny bubble in the clear tube.

On calipers which permit it, I use upper and lower bleeders (lower 1st).

And I like to prepare the stuff: I disassemble the wheel cylinders, paint them, and rebuild them (clean) with ATE brake grease, calipers, too. It used to be blue, now it's clear. Great stuff, and I figure everywhere the grease is means that much less water can fit in. Check the state of all the dust covers, and replace as needed.

I also use ATE paste behind calipers, etc, and the calipers need to be copper-greased at all the rubbing surfaces, after cleaning the surfaces with a wire brush Be caeful not to hurt anything rubber.

I use copper grease on the bleeder threads, and on the threads of the brake line fittings, and under them as much as I can. You'll thank yourself later.

Of course, check the brake lines for surface cracking when you bend the flexible bits.

That's all I can think of for now.

Hope that can help.

Mon Jul 08, 2019 4:26 pm

FreeBug wrote: For the names, it's actually kinda shameful, they're called master and slave :shock:

Great, now Colin Kaepernick will try to get these parts abolished !!!

Mon Jul 08, 2019 4:40 pm

Actually, there WAS a movement to abolish this language in auto lexicon. Probably came from my state... :roll:

Mon Jul 08, 2019 4:42 pm

KTPhil wrote: Zundfolge1432 wrote: I worked in a hydraulic shop building actuators for commercial airliners and we used a paste and fluid mix to assemble the dry components. I mention this because if M/C and wheel cylinders sit around they might be dry when you get them. It would be beneficial to prelube using assembly lube

VW used to mention a brake assembly paste of some sort but I never found their brand anywhere. I used a generic FLAPS variety years ago when I redid the brakes from scratch. I can't say it was needed but I followed VW's instructions where I could.

Anyone got a reference, and an equivalent for today?

And is it a different product depending on whether you use DOT 3/4 or DOT5?

Compatible w/ dot3,4,5.1 see back panel

Mon Jul 08, 2019 5:13 pm

Any new wheel cylinder should be taken apart and cleaned at min. I just had a new one that was plugged from sitting so long

Mon Jul 08, 2019 5:37 pm

I have the bleeding kits, ive bled brakes many times on my kawasaki bikes. And in never had success with vw.. or full success. The calipers at each wheel drum were made in china. Bought from concept1 in calgary. I installed and pre filled with fluid new brake assembly cylinder unit.

When i first bought the car everything worked. Was parked on driveway and one wheel drum has brake fluid leaking from it. So that is what initially started this endeavour

Tue Jul 09, 2019 1:12 am

I knew a guy who successfully bled his brakes (oldSstudebaker Lark) by setting up a bleed jar under each wheel, and open the bleeders slightly, and let it sit. His thinking was that liquid ran downhill. Not sure if this woud work with the VW's system, though.

Are you pumping slow enough? What's the quality like on the "buddy"? Maybe get a newer, better one?

This has been done MANY times throughout history. But sometimes, it's a real pain, not sure what makes it so. Hours of bleeding, yet still a spongey-feeling brake pedal.

Prsistance and perseverance should pay off, inless someting isn't working like it's supposed to.

I'd rebuild an old ATE cylinder twice before going chinese. It may be something is off. I once had an issue where the little M6 retaining screw on top with the copper washer was leaking, and spraying fluid everywhere at every pump. The MC was new.

Keep on trying. Hoses pinched? they can collapse internally, too, and even become one-way valves sometimes. How about the hardlines? They can take quite a bit of bending to get the MC out.

Tue Jul 09, 2019 1:19 am

KTPhil wrote: Actually, there WAS a movement to abolish this language in auto lexicon. Probably came from my state... :roll:

Updated to "boss/employee" cylinders. I guess even "lord/peasant" would still be softer. Ah, words.

How 'bout "judge/accused"?....or "warden/prisoner"? Or maybe "wife/husband"? "hot chick/pussy whipped" ? ...just thinking out loud, here...

Tue Jul 09, 2019 1:21 am

"pimp/ho"?

Tue Jul 09, 2019 2:30 am

chrisflstf wrote: Any new wheel cylinder should be taken apart and cleaned at min. I just had a new one that was plugged from sitting so long

This new wheel cylinder came with the beetle woody when i bought. Good chance it was sitting around for a few years new in the box in the shed before i installed it with my old man.

Tue Jul 09, 2019 2:57 am

In your case the first thing to do is isolate where the air is . If you clamp (brake/ fuel line clamps) all 4 flexible hoses and have a full pedal it rules out the master cylinder . Next remove one clamp at a time and see which corner or end is causing the low/no pedal .

To bleed ,I use a clear pipe that is a good fit on the nipple , make a loop up from the nipple (air rises) and then into a container with a hook so that I can hook onto the car .

Bleed the corners that cause the low pedal .

To start fresh ,start on the RHR and open the nipple , then slowly pump the pedal (only go to half pedal if you have a servo/booster) . It's good if you can get someone to do this but not important . also keep and eye on the fluid level . You need to pump enough fluid through to carry air bubbles through the system , (pumping the pedal with the nipple shut does nothing ,just compresses the air bubble but doesn't move it)
After half a dozen or so pumps , lock off the nipple and move to LHR . then to the front .

I normally have no issue bleeding , and have bled thousands of brakes over the last 35 years (professional mechanic) . Last month I did a friends Super , set it up with new Type3 cylinders and shoes etc . I had the car level on four stands and could not get the air out of the rear cylinders . After an hour of frustration I walked away till the next day . The next day I just jacked up the rear and the brakes bleed up straight away . whether having the rear up in the air and the cylinders not level made a difference I don't know .