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David Raistrick Samba Member
Joined: January 26, 2004 Posts: 533 Location: Geneva, Florida
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Posted: Thu Dec 13, 2012 9:56 pm Post subject: |
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chrisflstf wrote: |
Alot of good info here. Someone has spent alot of time researching this |
heh. just a few years. not to mention trying to find the right magic to do a disc conversion for my truck, too. |
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David Raistrick Samba Member
Joined: January 26, 2004 Posts: 533 Location: Geneva, Florida
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Posted: Thu Dec 13, 2012 10:00 pm Post subject: |
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smitty24 wrote: |
so David, you said you were NOT running the booster, correct? Just a standard dual circuit mc with residual valve removed? I can't remember what you said, or maybe it was a different poster. |
correct - no booster, stock '67 style dual circuit - one circuit to the fronts, one to the rear. that's a 22.2mm bore.
keeps pedal effort the same as stock.
increase the master bore and increase pedal effort but decrease travel. I'd recommend a booster - which I have a design for in my head, but it's complicated by trying to still be able to fill the master w/o adding an in-cab reservoir...
decrease the bore and decrease pedal effort (increasing travel!) |
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chrisflstf Samba Member
Joined: February 10, 2004 Posts: 3413 Location: San Diego
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Posted: Thu Dec 13, 2012 10:25 pm Post subject: |
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If you had stock 15" wheels, what would run you run? Larger rotor? |
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David Raistrick Samba Member
Joined: January 26, 2004 Posts: 533 Location: Geneva, Florida
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Posted: Thu Dec 13, 2012 10:58 pm Post subject: |
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chrisflstf wrote: |
If you had stock 15" wheels, what would run you run? Larger rotor? |
if 14" wheels weren't needed, there are a number of other kits out there with bigger rotors - CSP, oldspeed, wagenswest all have one -
You'd want to check with Nate to be sure, but I'm pretty sure he's got a version of the bustang kit that will fit pre-71 - http://www.wagenswest.com/partstore/index.php/71-79-bustangs.html
there are others out there as well - http://airkewld.com/index.php?product_id=155&p...Itemid=252
again, you'll want to do your own research as far as fitment - I know 15" stockers vary a good bit on internal dimensions, so you may still run into clearance issues.
there are also a number of rear brake solutions to fit 15" wheels... |
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kguarnotta Samba Member
Joined: April 01, 2004 Posts: 1160 Location: Woodstock, NH
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Posted: Fri Dec 14, 2012 7:23 am Post subject: |
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Thanks for the great write up. This is on the list of things I'd like to do to my bus. It is great to have an idea of what is involved. _________________ -Kevin
Lincoln, MA
'86 Triple Knob Syncro w/EJ22
'78 Westy
'69 Single Cab
'65 Kombi - EZ-Camper |
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chrisflstf Samba Member
Joined: February 10, 2004 Posts: 3413 Location: San Diego
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Posted: Wed Dec 19, 2012 3:26 pm Post subject: |
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Whats the diameter of the rotors? |
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cru62 Samba Member
Joined: December 31, 2002 Posts: 4117 Location: Margaritaville.....24/7
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Posted: Wed Dec 19, 2012 4:14 pm Post subject: |
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David Raistrick wrote: |
They all run roughly the same diameter rotor - 9 1/4" for the babystang, ~~10" for oldspeed's kit |
_________________ "My biggest worry is that when I die, my wife will sell all my parts for what I told her I paid for them"-Jon
Jokes about German sausage are the wurst.
Stop dead photo links! Post your photos to The Samba Gallery! |
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flemcadiddlehopper Samba Member
Joined: December 05, 2011 Posts: 2332 Location: Kelowna, BC. Canada.
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Posted: Wed Dec 19, 2012 8:38 pm Post subject: |
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The Bustangs are 11", but I think they are only for '71 and up. Too bad.
There is another thread now (making a comeback) that says the Saco ones will soon be vented rotors, but the price will change too.
Gordo. _________________ Everybody Dies....Some Never Live.
Retrograde Garage. Vintage Aircooled, and others. |
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David Raistrick Samba Member
Joined: January 26, 2004 Posts: 533 Location: Geneva, Florida
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Posted: Fri May 03, 2013 3:00 pm Post subject: |
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So a surprising update now that the rainy season is upon is here in Florida.
They suck! Once they get good and wet (5-10 miles of standing water) they're like having no front brakes at all. All I'm getting are my rear drums (which I can lock up if I stomp hard enough w/ the clutch in, but not lock the fronts).
Typically disks are -better- in the wet...so I'm confused.
Wonder if this is due to the lack of dust shield maybe? Lots of hotrod brake kits don't have dust shields....
Dunno. Sketchy as hell.
Noticed it primarily yesterday coming home from work, then again today. (it's been rainy all week, but managed to miss my drives to/from work until yesterday). Driving in this morning (dry) was fine. Home tonight (wet) was iffy.
Hrmph |
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Z Samba Member
Joined: June 15, 2003 Posts: 2517 Location: galveston, tx
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Posted: Fri May 03, 2013 3:39 pm Post subject: |
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That is surprising, and disappointing, news. I assume you'll contact Nate...please let us know what he says. |
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flemcadiddlehopper Samba Member
Joined: December 05, 2011 Posts: 2332 Location: Kelowna, BC. Canada.
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Posted: Fri May 03, 2013 11:55 pm Post subject: |
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So, looks like you need to figure out your pressures a bit more, because, like you mentioned, rain usually doesn't effect disc brakes.
Perhaps a proportioning valve to help overcome drum brake spring pressure would help with the lock up and the booster you've been thinking of to help the binders all around.
Scary situation to be in. make sure you let us know how you sorted it out.
Gordo. _________________ Everybody Dies....Some Never Live.
Retrograde Garage. Vintage Aircooled, and others. |
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MrPolak Samba Member
Joined: June 20, 2004 Posts: 1336 Location: AG ,atnaltA
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Posted: Sat May 04, 2013 10:02 am Post subject: |
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flemcadiddlehopper wrote: |
So, looks like you need to figure out your pressures a bit more, because, like you mentioned, rain usually doesn't effect disc brakes.
Perhaps a proportioning valve to help overcome drum brake spring pressure would help with the lock up and the booster you've been thinking of to help the binders all around.
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^^ X2
My car with 18'' open spoke wheels does get affected in heavy rain. It takes a split second to sweep water from disk surface.
A few questions I would ask:
1) How hard are the discs working in the dry? Are they doing their share? If not, is there blockage in the front circuit? If the front circuit is OK, a proportioning valve would help.
2) What is the static clearance between pads and discs?
3) Are the discs protruding from the inside of wheels? Most disc brakes are tucked inside and protected from rain. Some "dust shields" act as air flow management devices and direct air into the center of vented calipers for cooling. Air then flows between the two disc surfaces where inner vanes act like fan blades, in some designs, while increasing the cooling surface. |
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Nate@wagenswest Samba Member
Joined: September 11, 2002 Posts: 103 Location: Salem,Or
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Posted: Mon May 06, 2013 2:40 pm Post subject: |
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Because the Babystang is such a small package, and for good reason it is made to fit under stock 14 inch bus wheels. They do require more pressure form the master cylinder, most of the time we are assembling these brakes on lowered buses that have smaller than stock tires up front. Smaller tires = less leverage working against the brakes. In the lowered type application a proportioning valve is not always needed. On the other hand, if these brakes are used in a stock or larger than stock front tire application a proportioning valve is a good idea. An adjustable proportioning valve http://www.summitracing.com/search?keyword=proportioning%20valve&dds=1 with about a 10 to 20% reduction in pressure to the rear brakes should do the trick. _________________ I like the smell of leaded gas. |
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David Raistrick Samba Member
Joined: January 26, 2004 Posts: 533 Location: Geneva, Florida
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Posted: Mon May 06, 2013 2:51 pm Post subject: |
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flemcadiddlehopper wrote: |
So, looks like you need to figure out your pressures a bit more, because, like you mentioned, rain usually doesn't effect disc brakes.
Perhaps a proportioning valve to help overcome drum brake spring pressure would help with the lock up and the booster you've been thinking of to help the binders all around. |
but what does that have to do with them being wet or not? fronts lock up long before the rears (though I can lock all 4 up, as I did friday mid-day when some astard was driving the wrong way up a 1 lane one way road...) in the dry.
Pressures and bias don't change in the rain...... I'm just losing friction in the front pads but not the rears in the rain.
if you're suggesting I should have to re-bias for the wet...well.. please share what you're smoking. |
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David Raistrick Samba Member
Joined: January 26, 2004 Posts: 533 Location: Geneva, Florida
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Posted: Mon May 06, 2013 2:59 pm Post subject: |
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MrPolak wrote: |
1) How hard are the discs working in the dry? Are they doing their share? If not, is there blockage in the front circuit? If the front circuit is OK, a proportioning valve would help. |
Front's lock (my 27x8.5s) up nicely in the dry with normal pedal pressure. More pressure beyond that and the rears will lock too.
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2) What is the static clearance between pads and discs? |
much smaller than my inside mic will measure - and I'm not about to try to get plastigage in there. Especially since presumably you want the after-pressure-applied-and-released clearance..
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3) Are the discs protruding from the inside of wheels? Most disc brakes are tucked inside and protected from rain.
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To be clear - the problem seems to occur when I'm taking the slow roads home in the rain (aka ~1" of standing water) after 5-10 miles @ 35-45mph - gets progressively worse for the 25 mile drive home. By the time I'm trying to stop for the driveway it's just like using the e-brake only.
When I've driven the interstate in similar conditions (which is really just the first 15 miles or so - but at 65mph) I haven't noticed this before. |
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OG67westy Samba Member
Joined: September 05, 2008 Posts: 286 Location: San Marcos Texas 78666
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Posted: Mon May 06, 2013 4:35 pm Post subject: |
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I had been planning this for an upgrade soon. I'll be watching this thread with much interest... |
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flemcadiddlehopper Samba Member
Joined: December 05, 2011 Posts: 2332 Location: Kelowna, BC. Canada.
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Posted: Mon May 06, 2013 10:15 pm Post subject: |
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In the picture above of your disc, was that when newly installed or is that now? Looks new to me.
You have had the pads and rotors in for awhile now, so the pads and rotors should have been bedded in properly. I read in another thread that some of the disc brake conversions (Saco and Wilwood) have been using race compound pads. Do you think it's possible that the pad compound you have is "dry use only" ?
Do the pads have a venting cut in them or are they a solid block? Venting cuts also help dissipate water vapor.
Just thinking out loud here. I would share what I smoke but there's a border between us.
Gordo. _________________ Everybody Dies....Some Never Live.
Retrograde Garage. Vintage Aircooled, and others. |
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Nate@wagenswest Samba Member
Joined: September 11, 2002 Posts: 103 Location: Salem,Or
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David Raistrick Samba Member
Joined: January 26, 2004 Posts: 533 Location: Geneva, Florida
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Posted: Tue May 07, 2013 10:23 am Post subject: |
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flemcadiddlehopper wrote: |
In the picture above of your disc, was that when newly installed or is that now? Looks new to me. |
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You have had the pads and rotors in for awhile now, so the pads and rotors should have been bedded in properly. |
I used my typical bed in procedure (which is a bit more difficult in a stock powered bus! that ~20-30 > 60 accel takes a bit..), which is around 10 60>20 stops, then no brake application until after cool down (so coast-to-stop)
Mind you, that works better on light cars - trying that on a 7,000lb truck you can run out of brakes fast. heh.
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Do you think it's possible that the pad compound you have is "dry use only" ? Do the pads have a venting cut in them or are they a solid block? Venting cuts also help dissipate water vapor. |
Wilwood's bp-10 pad is definitely a street compound. No cuts.
Nate@wagenswest wrote: |
May Father drives a 1970 bus with these brakes on it, here in wet Oregon and it gets driven in the rain regularly, he said he hasn't noticed any brake fade in the rain but he hasn't taken it swimming either. |
Yeah - in florida the rain doesn't have anywhere to go, so heavy standing water is the norm.
Dunno. I'll keep trying to figure it out.
I've thought about making a shield, but I'd worry about the extra few mm between the caliper bracket and the spindle - since they're non-floating calipers, would that cause an off-center problem? |
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kguarnotta Samba Member
Joined: April 01, 2004 Posts: 1160 Location: Woodstock, NH
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Posted: Tue May 07, 2013 4:45 pm Post subject: |
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trying to follow this great thread - but lost you when you were describing the break-in period. Could you spell that out again? _________________ -Kevin
Lincoln, MA
'86 Triple Knob Syncro w/EJ22
'78 Westy
'69 Single Cab
'65 Kombi - EZ-Camper |
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