Important question

[89-W-Body-Regal]

My rear brake calipers have a spring on it. I am assuming it holds the parking brake cable in place and tightens it. When I was replacing the drivers side caliper the parking brake cable would not go back on the little notch that locks onto the caliper. I had to remove the spring to get it back on. I wasn’t able to put the spring back on. 
 

Now here comes to weird part. This is a reman ac delco caliper. I bleed the caliper and made sure the pedal was hard. I test drove the vehicle and stopped fine. I came back from the test drive and that rear wheel was smoking a lot. When I went to pull off the wheel I noticed that the wheel didn’t even spin, it was locked and this was with the parking brake off. The other wheel spin ok. Than I go to pull off the drivers side wheel and the caliper was frozen and I had a hard time taking it back off. I had to use a pry bar to remove it and damaged my pads doing it. I checked the piston to make sure it engage and disengage freely. That checked out ok. Without the spring going back on, the parking brake cable wasn’t fully attached tightly to the caliper. Do you think that might have caused the caliper to seize and make the rear wheel smoke ? I am thinking it didn’t spin because the cable wasn’t attached to the caliper tightly. I couldn’t figure out any other issue. I thought maybe I put too much grease on the pads and that’s why it smoked. The pads were even position good.

Here’s a pic with the spring on the caliper that I couldn’t get back on.

Edited June 22, 2021 by 89-W-Body-Regal

[Schurkey]

The service brake applies the piston hydraulically.

The park brake applies the piston mechanically using a screw-thread mechanism.

If the park brake mechanism isn't assembled correctly, the piston can be forced outward by the park brake mechanism even without the cable connected.

 

You're going to have to retract the piston, assemble the caliper correctly, verify that the rotor and bearings are still good, perhaps replace your damaged pads (NEVER apply grease to the pads!) and then re-adjust the park brake once the whole works is assembled.

 

On my '92 and '93 rear calipers, I used to retract the pistons by pulling the nut and washer off the rear of the caliper, removing the bracket, and then squeeze the piston back in--the screw would just spin in the caliper.  I don't remember any particular problems getting the bracket to re-attach with the nut and washer.  Maybe those calipers are different from what you have.  I haven't looked at those calipers in years.

[White93z34]

The spring is to assist in releasing the park brake. Not sure what the implications of not having it would be. Perhaps it would hinder normal operation. I would put it back and go from there, make sure the sliders move freely.

[55trucker]

Without the return spring there wouldn't be enough inertia to overcome the cable friction & release the park lever.

[89-W-Body-Regal]

On 6/22/2021 at 1:09 AM, Schurkey said:

The service brake applies the piston hydraulically.

The park brake applies the piston mechanically using a screw-thread mechanism.

If the park brake mechanism isn't assembled correctly, the piston can be forced outward by the park brake mechanism even without the cable connected.

 

You're going to have to retract the piston, assemble the caliper correctly, verify that the rotor and bearings are still good, perhaps replace your damaged pads (NEVER apply grease to the pads!) and then re-adjust the park brake once the whole works is assembled.

 

On my '92 and '93 rear calipers, I used to retract the pistons by pulling the nut and washer off the rear of the caliper, removing the bracket, and then squeeze the piston back in--the screw would just spin in the caliper.  I don't remember any particular problems getting the bracket to re-attach with the nut and washer.  Maybe those calipers are different from what you have.  I haven't looked at those calipers in years.

I use a caliper compressor kit to retract my piston back in but the rear calipers retract differently than the front calipers do. The thing I do notice with this rear caliber design is when it comes time to put new pads on the rear caliper’s piston doesn’t stop turning to a certain point after it has been retract back into the caliper. I had problems fitting new pads in the caliper installing it back onto the rotor. I didn’t know what to do from there. The front calipers stop turning the piston after it has been retracted into the caliper after a certain point. I don’t know if that makes sense. I can always make a video to demonstrate what I am taking about if nobody understands me.

Edited June 25, 2021 by 89-W-Body-Regal

[89-W-Body-Regal]

On 6/22/2021 at 6:47 PM, 55trucker said:

Without the return spring there wouldn't be enough inertia to overcome the cable friction & release the park lever.

Do you think that’s why the rear wheel was locked up and wasn’t able to spin like the other side wheel was causing it to smoke a lot during braking operation?

Edited June 25, 2021 by 89-W-Body-Regal

[55trucker]

1 hour ago, 89-W-Body-Regal said:

I use a caliper compressor kit to retract my piston back in but the rear calipers retract differently than the front calipers do. The thing I do notice with this rear caliber design is when it comes time to put new pads on the rear caliper’s piston doesn’t stop turning to a certain point after it has been retract back into the caliper. I had problems fitting new pads in the caliper installing it back onto the rotor. I didn’t know what to do from there. The front calipers stop turning the piston after it has been retracted into the caliper after a certain point. I don’t know if that makes sense. I can always make a video to demonstrate what I am taking about if nobody understands me.

1st point...the front caliper pistons do NOT rotate when pushed back into the calipers bores, they are not on a threaded stud that would require that action.

2nd point..open the bleeders screws at the calipers to release the fluid pressure out the bleeder when one is retracting the pistons. Doing this makes the job go easier. The fronts are dual pistons, if you leave the bleeder closed the fluid will act on each piston independently, while you're pushing one back in the other will be forced out. The other concern is driving dirty fluid back up into the system.

3rd point...the rear pistons DO come to a stop when fully retracted, as has been pointed out to get them back in without a great deal of fuss remove the rear parking lever from the stud & use the piston retractor to push them back in. Once they are seated to get the pads back on the face of the piston HAS to align with the short studs on the backside of the new pads. There also is the retaining clip that keeps the pads in place while one assembles the caliper to the rotor. If you haven't properly aligned the pads to the pistons the caliper won't go back onto the rotor at all.

To service the rear calipers get under the car and back off the park brake adjuster so both cables are completely free from tension of the park brake lever. With no tension there now one can remove the cables eyes from the park lever & then remove the lever so one can service the pistons to get the new pads on. When one has  got the new pads in & one has got the caliper fastened back onto the knuckle mount one will see that the pads are not snug up against the rotor, one can turn the stud with a wrench at the rear & you'll see that as it rotates it will force out the pads to contact the rotor. 

Here is where one has to set up the park lever, at full park brake application the cable/lever will come to a stop just short of the stop shoulder contact point on the casting that the cable passes thru. With a wrench you should be able to freely turn the stud to apply the park brake, do this and pull the wrench off the stud without turning the stud in the other direction. Now the park lever fits onto that hex, it can fit on in multiple angles but only one angle is going to give the proper force to apply the park brake. Without the spring in the picture align the lever onto the stud and loosely put the nut back on, if you have the lever in the right position the position of the lever should be at 50% of the levers full range of movement. With a prybar one should be able to force the lever further in the direction of brake application. Now go back in the other direction to release the lever, the lever will come up against the stop, the rotor will turn freely, apply the force again to apply the park brake, where does the cable hook on the end of the lever stop? It should be a little more than halfway. If that is where you are on both sides now you can put the springs back on. MAKE sure you have the rear seal & the thin thrust washer in place 1st.

Mark the position of the lever on the stud with a marker, remove the nut, without losing the lever position to the stud loop the spring on at both ends, position the lever over the end of the stud, (you'll see that one cannot get the lever back onto the stud completely), start the nut back on & slowly turn the nut to pull the lever into place, don't loose your lever position. Once the park levers are back on one can re-bleed the rears to check that no fluid has got in past the rear internal seal.

At this point are the park cables moving freely in their sheaths? One should be able to pull on the cable at eith ends & there should be little friction, the right cable is the one that will cause problems 1st because of it's length. Reattach the park brake cables to the calipers, now one can adjust them to set the park brake system. Properly adjusted there should be 3 pumps on the pedal to fully apply the park brake, (2 to the floor & the 3 a short stroke).

Do a visual when the park pedal has set the brake .......where are the park brake levers positioned? they should be near full application. If so put the wheels back on & manually see if you can turn the wheels by hand with the park brake both off & on.

Report back......

 

 

     

 

Edited June 25, 2021 by 55trucker

[89-W-Body-Regal]

On 6/25/2021 at 12:45 PM, 55trucker said:

1st point...the front caliper pistons do NOT rotate when pushed back into the calipers bores, they are not on a threaded stud that would require that action.

2nd point..open the bleeders screws at the calipers to release the fluid pressure out the bleeder when one is retracting the pistons. Doing this makes the job go easier. The fronts are dual pistons, if you leave the bleeder closed the fluid will act on each piston independently, while you're pushing one back in the other will be forced out. The other concern is driving dirty fluid back up into the system.

3rd point...the rear pistons DO come to a stop when fully retracted, as has been pointed out to get them back in without a great deal of fuss remove the rear parking lever from the stud & use the piston retractor to push them back in. Once they are seated to get the pads back on the face of the piston HAS to align with the short studs on the backside of the new pads. There also is the retaining clip that keeps the pads in place while one assembles the caliper to the rotor. If you haven't properly aligned the pads to the pistons the caliper won't go back onto the rotor at all.

To service the rear calipers get under the car and back off the park brake adjuster so both cables are completely free from tension of the park brake lever. With no tension there now one can remove the cables eyes from the park lever & then remove the lever so one can service the pistons to get the new pads on. When one has  got the new pads in & one has got the caliper fastened back onto the knuckle mount one will see that the pads are not snug up against the rotor, one can turn the stud with a wrench at the rear & you'll see that as it rotates it will force out the pads to contact the rotor. 

Here is where one has to set up the park lever, at full park brake application the cable/lever will come to a stop just short of the stop shoulder contact point on the casting that the cable passes thru. With a wrench you should be able to freely turn the stud to apply the park brake, do this and pull the wrench off the stud without turning the stud in the other direction. Now the park lever fits onto that hex, it can fit on in multiple angles but only one angle is going to give the proper force to apply the park brake. Without the spring in the picture align the lever onto the stud and loosely put the nut back on, if you have the lever in the right position the position of the lever should be at 50% of the levers full range of movement. With a prybar one should be able to force the lever further in the direction of brake application. Now go back in the other direction to release the lever, the lever will come up against the stop, the rotor will turn freely, apply the force again to apply the park brake, where does the cable hook on the end of the lever stop? It should be a little more than halfway. If that is where you are on both sides now you can put the springs back on. MAKE sure you have the rear seal & the thin thrust washer in place 1st.

Mark the position of the lever on the stud with a marker, remove the nut, without losing the lever position to the stud loop the spring on at both ends, position the lever over the end of the stud, (you'll see that one cannot get the lever back onto the stud completely), start the nut back on & slowly turn the nut to pull the lever into place, don't loose your lever position. Once the park levers are back on one can re-bleed the rears to check that no fluid has got in past the rear internal seal.

At this point are the park cables moving freely in their sheaths? One should be able to pull on the cable at eith ends & there should be little friction, the right cable is the one that will cause problems 1st because of it's length. Reattach the park brake cables to the calipers, now one can adjust them to set the park brake system. Properly adjusted there should be 3 pumps on the pedal to fully apply the park brake, (2 to the floor & the 3 a short stroke).

Do a visual when the park pedal has set the brake .......where are the park brake levers positioned? they should be near full application. If so put the wheels back on & manually see if you can turn the wheels by hand with the park brake both off & on.

Report back......

 

 

 Lol whew that’s a lot….to be honest I learn better with photos or a video, but that’s helpful also. But yeah I was able to fix it and I put another reman. caliber on just to be safe. What happened was, the reason the rear wheel would not spin was because the parking brake cable was not attached to the caliber correctly. If I did not remove that spring in picture everything would have worked like it should. I didn’t have any tool to compress that spring back on. So I just sent it back and got another one. I didn’t feel like fooling around with it. The one I sent back was a warranty caliber but didn’t look like it was rebuilt well so I sent it back and got another. The one that just came in looked better than the other I sent back. I installed it and did not have to remove the spring. I was able to attach the parking brake cable on there easily. If I didn’t remove the spring before, I wouldn’t have had that problem with the rear wheel not spinning, the caliber wouldn’t have been frozen and the parking brake would have worked on the one side. This time I check the drivers side calibers piston, it was able to move in and out making contact with the pads to rotor when I stepped on the brake pedal. I test drove it and it wasn’t smoking. I might have to rebleed the system because the pedal is still spongy. I had the caliber off for awhile because I had to send it back to get another so I still probably have to bleed some air out. But other than that it’s fine now. I also check the parking brake it locks like it should because the wheels didn’t spin with the brake on. When I released it, the one wheel that wasn’t spinning was able to spin good again.

Thank you 55 Trucker

 

Edited June 26, 2021 by 89-W-Body-Regal

[89-W-Body-Regal]

I did one thing stupid, I sent back warranty caliber along with the retainer for the parking brake cable that is supposed to fasten the cable onto the caliber. I found the part and order it. Thank god I found it because it’s discontinue

Edited June 26, 2021 by 89-W-Body-Regal