got in my big order from Bus depot for doing the brakes on the 2 door while the tank is out getting dipped.
Got a rebuild kit for doing the calipers, BOTH calipers Pistons were not only stuck, but their outer lips had been broken off by the last JERK who rebuilt them!!
the pain never ends!
FREAKING CALIPERS!!!
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vwbill
- Posts: 970
- Joined: Sat Feb 15, 2003 12:01 am
on yeah those were a pain!!
I have the my two old ones in that kinda state! I think I got only one piston to come out. I think I actually got rebuilds from Discount/Advance auto online called partsamerica.com i think. The number was 19-434/sku# 3750752 and 19-435/sku# 3750760. The core was only a buck on them?? They came with the hardware included. Bill
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ubercrap
- Posts: 1394
- Joined: Sun Apr 18, 2004 8:00 pm
I wonder how hard the BMW 320i brake caliper upgrade would be for the 412. Look at the writeup on the Pelican Parts site about the upgrade for the 914. Later cars are a little more difficult, though, from what I understand. I had a BMW 320i, and I thought the braking was OK, but nothing to write home about? I did have quite a few problems with the braking system, though. Maybe I never had them working at 100 percent? 
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ubercrap
- Posts: 1394
- Joined: Sun Apr 18, 2004 8:00 pm
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raygreenwood
- Posts: 11912
- Joined: Wed Jan 22, 2003 12:01 am
Axtually...the calipers on tehse things are more than enough as they are. What is needed...is vented rotors. If you can't get rid of the heat...it doesn't matter how many or big the brake pistons are. I cross drilled and chamfered the ones on the front of my 412. Brand new German rotors. It made a HUGE difference. Also....carefully chosen pads, teflon stainless hoses...and mintex shoes on the rear...and this thing stops on a dime from any speed. I will have discs on the rear as well soon. Ray
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DeathBus
- Posts: 1176
- Joined: Mon Sep 30, 2002 1:01 am
Going with the type 3 rear disc conversion? Id be carefull I have heard from alot of people that this will cause brake locking problems.raygreenwood wrote:Axtually...the calipers on tehse things are more than enough as they are. What is needed...is vented rotors. If you can't get rid of the heat...it doesn't matter how many or big the brake pistons are. I cross drilled and chamfered the ones on the front of my 412. Brand new German rotors. It made a HUGE difference. Also....carefully chosen pads, teflon stainless hoses...and mintex shoes on the rear...and this thing stops on a dime from any speed. I will have discs on the rear as well soon. Ray
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ubercrap
- Posts: 1394
- Joined: Sun Apr 18, 2004 8:00 pm
Oh yeah, the calipers look beefy enough, and the rotors are quite large for the time period/weight of the car actually, the solid rotors are the weak point. I bet they're fine for street driving...If you upgraded them drastically, I bet they would be OK as long the setup for front/rear bias is OK, a little overkill never hurts...raygreenwood wrote:Axtually...the calipers on tehse things are more than enough as they are. What is needed...is vented rotors. If you can't get rid of the heat...it doesn't matter how many or big the brake pistons are. I cross drilled and chamfered the ones on the front of my 412. Brand new German rotors. It made a HUGE difference. Also....carefully chosen pads, teflon stainless hoses...and mintex shoes on the rear...and this thing stops on a dime from any speed. I will have discs on the rear as well soon. Ray
Last edited by ubercrap on Fri Mar 04, 2005 9:04 pm, edited 2 times in total.
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raygreenwood
- Posts: 11912
- Joined: Wed Jan 22, 2003 12:01 am
.
Thats true...I agree! A little overkill never hurts. Just don't want to see you spend too much money on something that you could upgrade to way more than adequate a little cheaper...just looking out for you Dr crap!
So people have had problems on the rear type 3 set-up? On type 3's or 4's? I see some potential errors that many people make. I fond most peoples knowledge of brakes...to be rudimentry (no insults meant).
I only learned a lot about it due to driving 411/412's. I had to learn how brakes worked tro find out what could be scavenged for parts
The CB performance system.....I am not sure about. The accuracy of the caliper mounts...as well as the material seems a little suspect to me. I think they should NOT be aluminum. There is no way those could stay straight with heat. That woud bring the caliper out of parrallel....causing locking. I have seen several systems advertised for the rear of typ 3 with nodular iron mounts.
The problem is....the type 3 stub/hat will just go in the trash. Also, the backing plate thickness though the same as type 4....the stub axle carrier is slightly different on the type 4. In order to keep proper "pinch" on the outer race of the outer wheel bearing, the faces of the caliper mounts in the kits....may need to be machined lightly...or the bearing cover may need to be machined lightly. Also, the other mistake I see...is that in order to hook up their stock E-brake cables to the calipers.....many people have to bend them around. They should be shortened if necessary to keep them straight...and have a new hook or ball welded or swaged onto the end. Bending of the E-brake cable will cause locking up of the brake too.
Also,....you MUST use a rear brake balancing valve. The stock one is impossible to get parts for...though it is a nice adjustable design. There are many good aftermarket ones.
Lastly....I have not decided on a kit yet...as I have not yet been able to get anyone to tell me where ...and by whom... the calipers are made. They MUST be quality...or else the mounting surfaces may not be parrallel. I believe CB uses a GM style caliper. Should be good stuff....should be Kelsey hayes. The others..I don't know.
When putting a type 3 kit on a type 4...a lot of mocking up with the trailing arm, axle, rotor and caliper must be done ....on the work bench.
Firstly, use the type 4 stub axle and either a 914 or saab 900 rear rotor. The stub must have the outside edge of the flange turned a few milimeters to clear any casting flash and seat flat. Then the bearing cover must be torqued onto the rear casting...using a shim the exact thickness of the original backing plate...to make sure that the cover clamps with enough force to render the bearing race inside....motionlesss. Then....compare that thickness...wth the mounting surface of the caliper mount that goes in its place. Is it the same as the backing plate was?....does it allow the bearing cover to properly clamp? If not it must be machine...or the cover must.
Then..with the caliper and rotor properly mounted and torqued.....without pads...and with pistons bottomed in the bores....is the distance from each piston to the rotor exact.....and with the claiper then split....is the centerline of the caliper casting parralell to the rotor face? If not...again....it must be surface ...and then shimmed until it is.
Lastly...the stock regulator began regualting when brfake hydraulic pressure reached 525 psi. With the huge surface area of the drums shoes to spread out that force multiplication.....thats is not all that much pressure. What that means...is that when you are applying the brake....the pressure will go up until 525 psi is rached. Then...it will maintain that pressure...but not let it get any higher. It releases when you let go of the pedal. But...a disc brake is much more efficient. It has much lager piston area than the pistons in the drum brakes. It build pressuer faster. Also....because it has less surface area on the brake pad.....it build contact pressure there much faster. The brake pressure you need tro regulate to, may be much lower. Ray
Thats true...I agree! A little overkill never hurts. Just don't want to see you spend too much money on something that you could upgrade to way more than adequate a little cheaper...just looking out for you Dr crap!
So people have had problems on the rear type 3 set-up? On type 3's or 4's? I see some potential errors that many people make. I fond most peoples knowledge of brakes...to be rudimentry (no insults meant).
I only learned a lot about it due to driving 411/412's. I had to learn how brakes worked tro find out what could be scavenged for parts
The CB performance system.....I am not sure about. The accuracy of the caliper mounts...as well as the material seems a little suspect to me. I think they should NOT be aluminum. There is no way those could stay straight with heat. That woud bring the caliper out of parrallel....causing locking. I have seen several systems advertised for the rear of typ 3 with nodular iron mounts.
The problem is....the type 3 stub/hat will just go in the trash. Also, the backing plate thickness though the same as type 4....the stub axle carrier is slightly different on the type 4. In order to keep proper "pinch" on the outer race of the outer wheel bearing, the faces of the caliper mounts in the kits....may need to be machined lightly...or the bearing cover may need to be machined lightly. Also, the other mistake I see...is that in order to hook up their stock E-brake cables to the calipers.....many people have to bend them around. They should be shortened if necessary to keep them straight...and have a new hook or ball welded or swaged onto the end. Bending of the E-brake cable will cause locking up of the brake too.
Also,....you MUST use a rear brake balancing valve. The stock one is impossible to get parts for...though it is a nice adjustable design. There are many good aftermarket ones.
Lastly....I have not decided on a kit yet...as I have not yet been able to get anyone to tell me where ...and by whom... the calipers are made. They MUST be quality...or else the mounting surfaces may not be parrallel. I believe CB uses a GM style caliper. Should be good stuff....should be Kelsey hayes. The others..I don't know.
When putting a type 3 kit on a type 4...a lot of mocking up with the trailing arm, axle, rotor and caliper must be done ....on the work bench.
Firstly, use the type 4 stub axle and either a 914 or saab 900 rear rotor. The stub must have the outside edge of the flange turned a few milimeters to clear any casting flash and seat flat. Then the bearing cover must be torqued onto the rear casting...using a shim the exact thickness of the original backing plate...to make sure that the cover clamps with enough force to render the bearing race inside....motionlesss. Then....compare that thickness...wth the mounting surface of the caliper mount that goes in its place. Is it the same as the backing plate was?....does it allow the bearing cover to properly clamp? If not it must be machine...or the cover must.
Then..with the caliper and rotor properly mounted and torqued.....without pads...and with pistons bottomed in the bores....is the distance from each piston to the rotor exact.....and with the claiper then split....is the centerline of the caliper casting parralell to the rotor face? If not...again....it must be surface ...and then shimmed until it is.
Lastly...the stock regulator began regualting when brfake hydraulic pressure reached 525 psi. With the huge surface area of the drums shoes to spread out that force multiplication.....thats is not all that much pressure. What that means...is that when you are applying the brake....the pressure will go up until 525 psi is rached. Then...it will maintain that pressure...but not let it get any higher. It releases when you let go of the pedal. But...a disc brake is much more efficient. It has much lager piston area than the pistons in the drum brakes. It build pressuer faster. Also....because it has less surface area on the brake pad.....it build contact pressure there much faster. The brake pressure you need tro regulate to, may be much lower. Ray
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DeathBus
- Posts: 1176
- Joined: Mon Sep 30, 2002 1:01 am
I have heard the locking problem occuring on Beetles with rear discs, and Type 3's, I have yet to hear of any Type 4's with the type 3 set up, but I am sure it would function the same. All that I can suspect is that the guys who installed them did not bleed them correctly and this was causing problems, this was on several Beetles and 2 or 3 Type 3's.
I do like the notion of converting the 914 rear to be used.
I do like the notion of converting the 914 rear to be used.
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vwbill
- Posts: 970
- Joined: Sat Feb 15, 2003 12:01 am
Why rear disc?
Just a dumb question, why use rear disc brakes? Doesnt 70-75 percent of the braking come from the front brakes? Where is the problems with the 412 system? Brake master, wheel cylinders, rotors, proportioning valve, pads,shoes? Could you have the front rotors drilled? Use a better front pad/Shoes? bill
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ubercrap
- Posts: 1394
- Joined: Sun Apr 18, 2004 8:00 pm
Yeah, really drum brakes in the rear work fine in most regular driving. Discs are better, but probably one would be hard pressed to tell the difference in a seat-of-the-pants comparison in most situations I bet. Still, I'm not a fan of drum brakes at all (hate working on them, crappy looks, old technology) As Ray mentioned, drilled front rotors (I would prefer slotted probably) and some good metallic pads make a big difference, along with making sure the rest of the system is tip-top. Any "spirited" driving would probably show the weaknesses of the solid rotor/drum setup though, like on a track or autocrossing, etc...
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raygreenwood
- Posts: 11912
- Joined: Wed Jan 22, 2003 12:01 am
A couple great reasons for rear discs. (1) They don't fade and they shed heat faster. (2) Decent drums for the type 4 are about impossible to get. The brazilian stuff is sh*t...machined out of round. It kills rar wheel bearings. (3) When I lived in Atlanta...and commutted to work,the brakes had to be adjusted about every two weeks. If you skipped a few adjustments, it put too much bias to the front causing them to overwork, then the rear would want to have a too far forward enertial shift, this overheats the front brakes, it wears out the front pads out faster.
In Dallas...I have to adjust the rear drums about once a month.
Rear discs and proper brake balancer adjustment help keep the rear to front enertia shift balanced better. A lot of those rules of thumb...70% front and 30% rear...are based around front engined vehicle thought. Since most of the weight is in the rear...if you can get that mass to to slow down quicker before and without locking the brakes...it will keep teh rear end down..so it wil not tilt as far forward. A decent disc is only slight more efficient. The rear 412 drums work great.,...but the drums are just too hard to get. Ray
In Dallas...I have to adjust the rear drums about once a month.
Rear discs and proper brake balancer adjustment help keep the rear to front enertia shift balanced better. A lot of those rules of thumb...70% front and 30% rear...are based around front engined vehicle thought. Since most of the weight is in the rear...if you can get that mass to to slow down quicker before and without locking the brakes...it will keep teh rear end down..so it wil not tilt as far forward. A decent disc is only slight more efficient. The rear 412 drums work great.,...but the drums are just too hard to get. Ray
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67 T1
- Posts: 264
- Joined: Thu Apr 22, 2004 2:03 pm
Ray (or anyone), do you know the number on those drums. While going through some stuff that was given to me when I bought the car, there were two drums. I just put them aside without really thinking about it. but I'd like to know proper part #. I'll see if I can find a "Made in..." on them. bet they're brazil nuts, I mean drums.
There were also some pads, I'll check for #. Busdepot sent me some that were smaller than T-1 pads, have no idea what they really go on.
There were also some pads, I'll check for #. Busdepot sent me some that were smaller than T-1 pads, have no idea what they really go on.