Hello again... ok, so it hasn't been that long... but I need some help with this one last part!

E-brake cables for the rear disk brakes. I finally got it all together but it still doesn't feel right. Here is my thought on what is happening: I got the rear disks from a 78 Fleetwood, rebuilt everything and using 79 TA rotors. Everything went together fine and I finally got the ebrake cables hooked up and all, but there still is not much braking (if any!) from the rear brakes. When I installed them, they were basically 'wide-open' meaning the piston was all the way in the bore. I figured that after bleeding them and using them a couple of times, they would be right, but I still cannot any braking out of them. Even if I push the ebrake pedal all the way in, I can still turn the wheels by hand, but hear a slight rubbing. What I'm pretty sure is happening is that the piston is going back in all the way and any movement is being used to take up the extra space between the pads and rotor. These are the rear Caddy calipers with the built-in ebrake mechanism, so how do I get it to adjust correctly?

TIA,
Bill C.


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Bill C.
'71 SS (now with 467BBC)
'70 Nova 350/700r4
ACES #2780
Colo Spgs, CO

BC, I don't have this type on my car, but the kit that is sold my MasterPower Brakes (www.mpbrakes.com) you can read the assembly instructions. Every time the parking brakes is on, it adjusts the piston out to the correct distance from the rotor (if needed). That is if it was properly centered over the rotor when it was orginaly setup. The piston should be .030 in. away from the rotor on both sides to be correct after bleeding (?). Sounds like the piston is not comming out of the casting far enough. Does the cablier move freely?

Roy 65Camino Team Member Gold #74
355ci. 700r4 4wheel disk brakes

I checked the mpbrakes.com and their kit uses the El Dorado rear calipers. These have an internal self adjusting mec. inside of the piston. It is adjusted each time the parking brake is applied. Are you sure the disk that you have the correct rotor thickness for your calipers??
Team Member #74

Roy,
The caliper was properly centered when installed and can move freely as I have knocked it back and forth a few times to be sure. I have not checked the actual distance from the rotor, but I know it is more than 0.030", so how do I get it to the .030"?? The calipers I am using are the same as the Eldorado ones as far as mechanicals go and also have the internal adjusting mechanism, but it doesn't seem to be adjusting. If I watch it while the ebrake lever is moved, it does push the piston out, but the piston 'sucks' back in when the lever is released. Yes, the rotors I am using are the same thickness as stock Caddy ones and are brand new as is everything else. Any more ideas??

Thanks again,
Bill C.

Do the pistons have small notches along their edges. On some foreign makes the piston must be turned to retreat back into the casting. These may need to be turned to extend out (for primary adjustment). Remember the piston only moves very little both in and out on regular brake applications. Did you rebuild these calipers? Sounds like the auto adjustment mec. is not working correctly. I would try applying the parking brake many times to see if they extend like they should.

Roy 65Camino
Team Member gold #74

Bill,
Just got done playing around with my Fleetwood calipers that I rebuilt for my rear disc swap (thanks for the rebuild instructions by the way!).
With the spring out of the built in e-brake lever (on the caliper) and pulling and pushing on the lever, my piston will move out but not back in...Unless I get out the piston removal tool to screw the piston back into its sleeve, I can't get it to go back into its sleeve on its own. Is it possible to have the racheting screws (the screws that screw into the piston and are attached by the e-brake lever on the caliper) in the wrong caliper? Meaning is there a right and left racheting screw? I wouldn't think so. I hate to say it, but you may have to unbolt these and take them apart to see what is going on.

Look at it this way. This is just practice for the rear disc swap on the Nova!! And at least you have the Nova to drive while you do this. Let me know if you need any help.

Joe

BC, after checking the such function on this subject, please contact chev-hell, member #783, at john@chevelles.com. He has hands on expierence with the Cad, rear brakes. I am sure he would be glad to help you thru with is adjustment.

Roy 65Camino
Team Chevelle Gold member 374
ACES Member 31788

65,
Thanks again... these pistons to have notches in them, but there is a bigger notch that the little bump on the back of the brake pad must fit into, so the piston have to be installed and basically kept in the same position. I think you actually hit it in that I need to apply the ebrake several hundred times to get it adjusted per some locals around here. I'll try John and see what he has to say.

Joe,
I believe that is how they are supposed to work. I couldn't get mine to go back in either before I rebuilt them or after if the caliper was on the bench. Installed on the car, it works how it should meaning if I watch it, it pushes out and then retracts when you let off the bracket. I was able to adjust one last night by fully compressing the ebrake lever, then unscrewing it from the screw, swing the lever over to the uncompressed position and re-attach it there. Now that side works pretty good. I could not get the other side to do the same thing, so I still have too much play in it.

I don't think you can get the screws backwards, I think it has to do with the fact that while playing with them on the bench, you cannot provide any resistance to the piston moving out, thus causing it to want to retract back in when you release the lever. Also, does the piston turn when you do that? When installed, the piston cannot turn because of the notch on the front that locks it to the pad. Try putting in the brake pad so the piston cannot spin and just move in and out. Let me know how it goes... You didn't happen to buy a Chiltons or whatever for the Caddies that might show the correct adjusting procedures?

So it looks and feels like I got one side adjusted better, it stops a little better now. Now if I can just get the other one...

Thanks again,
Bill C.

ok, first id' like to know how you got both e-brakes to pull http://www.chevelles.com/forum/smile.gif and to answer your question, remove the spring and lever on the rear of the calaper, the turn the bolt head (that the lever connects to) to tighten the brakes up, the pad should almost drag the rotor, this is how they are set up and once done, the e/brake will keep them adjusted for you, i only have 1 side with the e brake, the other is pulling backwards and i didn't wann rig up a pulley system. i adjust mine every few months you can tell when they aren't grabbing like they should http://www.chevelles.com/forum/smile.gif but once you've tightened the pistons closer to the rotor, try to put the lever back on so it's in the position where it will have full travel when the e brake is applied, sometimes it won't work well, another way is to (sometimes this works, sometimes it didn't depends on how far outta wack they are) press brake hard, then e'brake, then brake then release e brake (as if you were stopping over and over ) if you do it MANY times it may work the piston out as needed, keep in mind you CAN"T bleed it out for adjustment (which sucks IMHO) let me know what happens

FYI the calaper has a piston, which has a smaller piston inside it only connected by an o-ring seal and the inner piston has threads (like gear threads) then there is a long screw that goes into it and all the way out the back to the lever, the lever turns the screw forcing the inner piston to push on the outer piston moving it out, now since the inner is not hard connected to the outer piston, it can turn inside it to an extent, so when the e brake is applied it will mash to the rotor yet give if it's too close. and there's too much pressure on it. but keep in mind if it's too far away to begin with, it will just turn it out toward the calaper, but when unleashed it will just turn it back toward the calaper. YES it's a DAMN MESS, there's gotta be an ezier way but once done' you will feel the difference.

when i get frustrated, i take it to a brake shop that does caddies, and have them adjust it for me http://www.chevelles.com/forum/smile.gif and buy their lunch...

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1970 SS396 AKA 454/4spd
My Chev-Hell Page (http://hometown.aol.com/jnkb2cool/home.html)
GOLD Member #783
Ft.Worth, Tx
(OO=ss=OO)

Thanks for the reply John, pulling the lever is exactly what I did on one side and it worked good. The problem I ran into was that the other side was already out to almost the limit and it will not turn far enough out to get the lever back on in a new position. i guess I'll try the braking/ebrake thing for a while to see if that helps, then take it in if I can't get it.

As far as getting both to pull... it wasn't that bad, I just replaced both the e-brake cables and the intermediate cable with ones designed for rear calipers. Basically I just searched through a parts book until I found a combination that I thought would work. The two E-brake cables lengths are not that critical as you can adjust the intermediate cable to shorten or lengthen it if necessary. Also, like you said, one side comes in from the front like your normal 'stock' e-brake cable, but the other side has to come in from the rear, so mine goes over the axle and loops in from the back. I founf that the new cables I bought were actually more pliable than the old stock ones, so I was able to keep it fairly tight to the axle. Let me know if you want the part numbers, it took me several intermediate cables to get it right, but the latest one fit real good and now actually looks stock.

Thanks,
Bill C.

Bill, Could you post those part numbers for future reference for people wanting to do this swap?

Joe

Sure Joe,
Here's what I found out:

The stock 71 Chevelle uses the same rear E-brake cable on both sides and when I looked it up, it is part number 2655. It has specs of 24 1/2" sheath and 35 1/2" cable. The stock intermediate cable is listed as part number 2640 and is 79" long.

After lots of measuring and trying, I ended up using rear disk cables off of 'Who-knows-what'? The drivers side is part number 3095 is has 29 1/8" sheath and 40 1/2" cable. This side goes into the e-brake lever from the front, but I did have to clearance the shock mount bracket slightly to get it in straight.

The passenger side ended up being part number 3219 and has 36 1/2" sheath and 63 1/2" cable. This side has to come in fromt he rear, so I looped it over the axle and down into the e-brake bracket and it worked really nice. It also has an auxillary sheath that is nice to put where it rubs on the floor pan. You could probably get away with a shorter cable and make up the difference with a longer intermediate cable, but it was the only one I could find that had the sheath length I wanted. You will find that the sheath length is the most critical...

After several attempts, I found the intermediate cable number 8250 at 59 3/8" to be about perfect. You have several inches of adjustment with the adjuster.

Everything is hooked up and working great, I just can't seem to get the rears adjusted correctly, so they are pretty much ineffective right now, so I'll try again this weekend.

Let me know if you have any other questions, and hopefully I'll get some pictures soon if anyone is interested.

Bill C.

Bill,
Pics would be very nice...especially of the e-brakes (routing and placement). Let me know if you need help posting them.

Oh and by the way. I took your advise and went to the 'yard on a cooler day to see if I could have a "good day" at the junkyard. I found three rear disc setups. http://www.chevelles.com/forum/biggrin.gif http://www.chevelles.com/forum/biggrin.gif Two from '78 Fleetwoods and one from a '79 Seville. I chose to pull one set off one of the Fleetwoods, and now I know why the car was put to rest in the 'yard in the first place....the rearend locked up and welded the spider gears together. http://www.chevelles.com/forum/mad.gif The 'yard closed before I could knab the other set-ups. http://www.chevelles.com/forum/mad.gif I'll see if I can go back next week and grab them.

Joe

don't know if this problem was ever solved but i saw this on Master power web site.

"NOTE:If you are using Cadillac ElDorado rear calipers there are some important things you should know. One of the biggest advantages of a disc brake system is the fool proof self adjuster. Not so with this rear GM system. The rear calipers adjust off the parking brake. The parking brake is incorporated into the caliper. You must set the parking brake every time you park the car.The rear caliper pitons utilize a one way clutch inside the caliper piston. When the parking brake is applied the clutch senses when there is .030" or more clearence between the friction material and the rotor on the inboard side. When there is more than .030" the clutch turns inside the piston adjusting it out keeping the rear brakes adjusted. If you do not set your parking brake every time you will start to lose brake pedal (low and spongy) and the adjuster mechanism will not work any longer."

I can't imagine every cadillac owner in the world setting the parking brake every time they stopped. Anyone have any thoughts? Would this be the same if you used camaro rear calipers? :confused:

Originally posted by mattchas:
Would this be the same if you used camaro rear calipers? :confused: mattchas,
Glad to see you using the search function graemlins/thumbsup.gif

For the Trans Am/Caddy setup, yes you need to use the e-brake mechanism to adjust the calipers. A lot of cars use this system. My daily driver (an import) even uses this system still (its a '93).

For the '89-'97 F-body system this is not the case. A system of linkages forces the caliper to slide on its pins and abutment to force the caliper piston against the rotor. For the '98-'02 F-body system (and C5 rear disc system) there is a mini drum brake system inside the rotor's "hat" that will grab and lock, thus that's your e-brake.

graemlins/beers.gif

Joe

So is it necessary to set the E brake every time you shut the car off? Seems like alot of hassle. WHat about the 98-02 rears? Do the bolt straight to a 66 10 bolt axle without any mods? Haven't run across that swap yet. Did you see my post on the fronts from a 98-02 F body?

As a side mote, this is a great site. The fact that the old forums are kept and can be accessed is awesome. A wealth of info for any car nut! graemlins/hurray.gif Thanks for being a part of it!

hey guys, dont forget about this option.
http://members.aol.com/smartasreality/page08.html
graemlins/thumbsup.gif

I don't find it necessary to set the parking brake every time, but I'm sure it's a good habit to get into! Once a month or so, I'll simply apply the parking brake repeatedly for like 5 times and go from there. Once you drive the car a while, you'll notice when the pads are wearing a bit and need the 'slack' taken up a bit. Then the pedal comes up a bit and feels better.

Bill C.

It is a very good habit to get into. Not that it has to do with my rear brakes....but My 95 Impala SS has over 150K and still running on the original trans. I attribute it to setting my parking brake while it is in Nuetral and then taking my foot off of the brake pedal, letting the parking brake take the load of the car, and THEN setting the trans to PARK. My trans never sees a preload, and has never busted on me...A lot of the guys on the Impala SS forums go thru trannies like crazy! Maybe from racing them or abusing them, but I notice that these guys also never set their parking brakes.

But now that I have my rear Caddy brakes on my 66 Malibu, I'm already in the habit of setting the parking brake, and will continue to do so and keep the preload off of my M22.

while your on the subject, i will not be needing these 80-85 cadillac Seville, eldorado .... rear caliper parking brake and rebuild parts. these are new parts. email me if anyone is interested. smile.gif
http://www.chevelles.com/showroom/FO_FDYFO/fordparts.jpg