Brake upgrade for 57 chevy rear cad calipers adjustment

[BFS57]

Hello;
Me again bighting off WAY more than I can chew!!
Bought this disc brake conversion for my 57. (everything included even ss lines) So far everything has fit and been pretty good, UNTILL NOW!
This kit included a rear disc set up with 80's Cadillac Calipers. These calipers have an emergency brake built into them which connects to the 57's e brake handle. Everything fit just fine but now I am trying to ADJUST the rear e brake on the caliper and this thing defies logic!!! You are supposed to take the e brake lever off, and the two seals behind it and there is a 13mm head on the "adjusting screw" that you are supposed to adjust so that the piston on the caliper makes brakes work!
Well, I first thought that everything should work fine given how everything fit after installation and skipped this adjusting part and went to the "bleeding" process! The adjustment was supposed to be done before the bleeding!
I have printed and read everything pertaining to this set up and every one of the articles are different!! The one that came with the kit is different than the one from CPP as well as Speedway and a couple others for this exact same caliper!!!
Furthermore, almost every article expresses how important this adjusting process is for pedal firmness and rear brake operation!!
Question is IS ANYONE HERE FRAMILIAR WITH THIS CADILLAC CALIPER AND THE ADJUSTMENT IT NEEDS AND HOW TO DO THIS RIGHT!!!!
A couple articles seemed to say that this adjustment is a "blind" adjustment which I agree, I don't see anything happening when I am trying to adjust this mess.
If I had known this was going to happen I would of opted for a rear Drum style brake upgrade!! (car had disc/drum before.

Bruce

[kb426]

I found this. It could be helpful:

[BFS57]

I found this. It could be helpful:

[/quote

Thanks for the clip. I found another one from MBM which are the brakes I got for the rear.
Another thing I read is that while bleeding the brakes the caliper needs to be Perpindicular to the ground so that all the air in the calipers can be let out. The article I read this from was a guy that was fixing his car parked with the front higher than the rear. My car is parked where the rear end is higher than the front, In these cases it was said that the caliper would have to be un mounted in order for it to be positioned to be properly blead!!! Makes sense!

Bruce

[WZ JUNK]

I found this. It could be helpful:

[/quote

Thanks for the clip. I found another one from MBM which are the brakes I got for the rear.
Another thing I read is that while bleeding the brakes the caliper needs to be Perpindicular to the ground so that all the air in the calipers can be let out. The article I read this from was a guy that was fixing his car parked with the front higher than the rear. My car is parked where the rear end is higher than the front, In these cases it was said that the caliper would have to be un mounted in order for it to be positioned to be properly blead!!! Makes sense!

Bruce

I am working on this same problem.  The way I understand the technic is that you remove the lever arm, rotate the inner assembly slightly, reattach the arm, test to see if you have it adjusted.  Go in small increments and test each time.  You do not want to rotate it to far.  When finished the emergency brake should work and the arm should be slight above the stop that is cast into the caliper.


I have not adjusted mine yet.  This is just my understanding of what needs to be done.  I know that it must be set correct for your brakes to work well and for your emergency brake to function.  Also you must use your emergency brake occasionally to make the self adjusting feature to work.


John

[348tripower]

John,
What you understand about the adjustment is correct. The shaft will actually slip inside and allow you to dial it in. I found the best way to adjust them was to clamp the rotor in a vise and do it off the car.
Don

[BFS57]

John,
What you understand about the adjustment is correct. The shaft will actually slip inside and allow you to dial it in. I found the best way to adjust them was to clamp the rotor in a vise and do it off the car.
Don[/quot

Hello;
Don't own a vise! When they told me I had to weld the brackets to the rear end, I told them the only kind of welding I do is with a soldering iron. Well, I found a way around that problem. I used hose brackets to clamp the line tight to the rear end with rubber isolators!!!!!!
Here is what I know. The pistons on my set up, need to come out about 3/16" to contact the pad on the side. Couldn't seem to get that much out off them! Then the video I got from MBM shows that to bleed the system properly you have to take the calipers loose but not off, still in contact with the rotors to bleed the brakes. New word, "perpendicular" with the ground! Makes sense that if the vehicle is slanted with the ground you MAY think the system will bleed right but evidently NOT SO!
My biggest problem is how to get the piston to go out enough to contact the pad, the pad is touching the rotors but I can still turn them. I read someplace that I might have to remove the calipers and use a "spanner" wrench to rotate the piston out enough
So far I have at least a couple different methods to use to get this done. We will be at it tomorrow!
Thanks for all this wonderful info! I would of been lost without all off you!!!

Bruce

[BFS57]

Hello;
Well, played around with this set up today. Adjusted the caliper so that the rotor would spin without emergency brake and not spin when the e brake was applied! Got the car down on all fours and the pedal seemed good but no stopping power and that GD e brake didn't work!!
This set up has me scratching my rear and head and goin no where! Defies logic, not unless I missed something???

Bruce

[wayne petty]

i use a slightly modified AC ratcheting box end wrench or a seriously ground down 9/16" crow foot line wrench to bolt on to the parking brake screw..

what the video above did not say.. is that the 5 notches in the face of the piston are for a reason. one is to align the bump in the top of the inner pad to prevent the piston from turning.. the other 4 are clearance for the rivets used to hold the pads to the backing plate.

what the other linked video is NOT showing is inside the piston there are several more parts.. the high lead screw goes into an inner piston that has its own seal inside the main piston.  the inner piston has to turn to adjust the brakes.


this is a video i did of an eldorado a few years ago with a low brake pedal..  

i was able to just reposition the lever on the hex shaft and got it working within reason..   if you can get the screw all the way out against the stop.. and get the lever on so you have more than 5/16 and less than about 3/4" of distance from the hard stop to the lever you are good..  

i prefer to shoot for the 10MM or 3/8 measurement.

if you can make a tool that will fit on the hex under the nut..  you can rotate the pin hopefully without spinning the outer piston and get the inner piston to free up .. how many times will you have to do this fraction of a turn to get the lever to mount in the proper spot..

HUGE Warning.. every once in a while.. the stamped cage inside the outer piston would come off requiring the disassembly of the caliper.. its really not hard..    huge hint 2.. the seal for the inner piston is not available in caliper kits..  when i did these a lot.. i always kept a bottle of McKays brake assembly lube around.. i always used that on the seal and in the now polished bore in the outer piston..  i would polish it with 600 to 1200 wet or dry using BRAKE FLUID as a lube not water or solvent of any kind.. not ever brake cleaner..  if you are going to use brake cleaner.. you MUST let the parts sit in the sun for an hour for it to all evaporate so you don't trap any solvents inside..

in the other video.. you can see he puts a roll of tape between the piston and the caliper.. this stops the big spring from slamming the piston out and hitting the side of the piston putting a gash in it..  gashes can't be fixed safely on piston sides..  not even little ones..

why not just use conventional front calipers on the rear brackets..  because if you are mounting this on a conventional rear end .. you will have some axle end play..  when cornering the axles slide in and out slightly.. this can retract the pistons leaving your brake with NOT enough volume to push the pistons back out..  the parking brake holds the pistons out so you don't end up with excessive pedal travel.

[BFS57]

i use a slightly modified AC ratcheting box end wrench or a seriously ground down 9/16" crow foot line wrench to bolt on to the parking brake screw..

what the video above did not say.. is that the 5 notches in the face of the piston are for a reason. one is to align the bump in the top of the inner pad to prevent the piston from turning.. the other 4 are clearance for the rivets used to hold the pads to the backing plate.

what the other linked video is NOT showing is inside the piston there are several more parts.. the high lead screw goes into an inner piston that has its own seal inside the main piston.  the inner piston has to turn to adjust the brakes.


this is a video i did of an eldorado a few years ago with a low brake pedal..  

i was able to just reposition the lever on the hex shaft and got it working within reason..   if you can get the screw all the way out against the stop.. and get the lever on so you have more than 5/16 and less than about 3/4" of distance from the hard stop to the lever you are good..  

i prefer to shoot for the 10MM or 3/8 measurement.

if you can make a tool that will fit on the hex under the nut..  you can rotate the pin hopefully without spinning the outer piston and get the inner piston to free up .. how many times will you have to do this fraction of a turn to get the lever to mount in the proper spot..

HUGE Warning.. every once in a while.. the stamped cage inside the outer piston would come off requiring the disassembly of the caliper.. its really not hard..    huge hint 2.. the seal for the inner piston is not available in caliper kits..  when i did these a lot.. i always kept a bottle of McKays brake assembly lube around.. i always used that on the seal and in the now polished bore in the outer piston..  i would polish it with 600 to 1200 wet or dry using BRAKE FLUID as a lube not water or solvent of any kind.. not ever brake cleaner..  if you are going to use brake cleaner.. you MUST let the parts sit in the sun for an hour for it to all evaporate so you don't trap any solvents inside..

in the other video.. you can see he puts a roll of tape between the piston and the caliper.. this stops the big spring from slamming the piston out and hitting the side of the piston putting a gash in it..  gashes can't be fixed safely on piston sides..  not even little ones..

why not just use conventional front calipers on the rear brackets..  because if you are mounting this on a conventional rear end .. you will have some axle end play..  when cornering the axles slide in and out slightly.. this can retract the pistons leaving your brake with NOT enough volume to push the pistons back out..  the parking brake holds the pistons out so you don't end up with excessive pedal travel.

Hello;
UPDATE: I took the e brake cables off (again!) and the e brake levers and adjusted the bolt inside (attached to the lever) till it wouldn't go any more!! The video I had from MBM says "you can't over adjust these calipers" Put everything back together and tightened up the  yoke under the car.
Went inside and pulled the handle and tested the Brakes. The one on the drivers side was not contacting the disc still, but if I put mild tension on the cable, it would lock up the disc. The Passengers side was working as it should! So I guessed at a cure for this and what I decided was, that the ebrake cable wasn't "centered" (fat chance of adjusting that perfect) so I opted to loosen the yoke (about the 10th time) pulled the cable end back from the lever and inserted a washer over the cable and "crushed it in place"! Back to adjust the yoke.  Got in and pulled the lever inside and WA-LA each side was locking the disc!!! Further examination and measurement gave me 3/16" from lever stop to engaged!! Which from what I have read is absolutely PERFECT!!
Next, gotta loosen the yoke again!!! and take each caliper, remove the top pin and loosen the bottom pin, "swivel" the caliper till the bleeder screw is level with the ground and bleed each of the calipers for trapped air inside!

Bruce

[UGLY OLDS]

WOW..   After seeing all the issues that you & Don, (348 Tripower), have gone through with these calipers, it makes me wonder if rear disc brakes are even worth the trouble on our early cars  :?:  :?:  

Bob...

[BFS57]

WOW..   After seeing all the issues that you & Don, (348 Tripower), have gone through with these calipers, it makes me wonder if rear disc brakes are even worth the trouble on our early cars  :?:  :?:  

Bob...

HELLO;
i did see a article where the guy said that there are 2 kinds of users, ones that HATE This Mod! and Ones that love it. The difference between the two is that the ones who love it know how to adjust the calipers! the ones that don't is because they can't figure out how to get the proper settings!!!!

Bruce (