Tips for replacing backing plate

[DOG]

Hello all,

I ran into a problem after converting my 87 GN from the powermaster brake system over to a vacuum system. As i was bleeding the rear drums the wheel cylinder busted. Then I attempted to remove the wheel cylinder without knowledge of the clamp holding it on the back of the backing plate thus causing me to warp the backing plate. I figured i might as well replace both wheel cylinders and now i am ready to tackle this project with a mechanic buddy.
I have new backing plates (2)
drum brake kit (2)
brake fluid
After work today i will check to see if i have a posi or limlited slip in the rear end. (Can someone tell which fluid is best for a daily driver for each)
Do i need a special tool to remove the axle or what size socket i will need. Also if anyone know the torque specs.

Thank you all in advance for your help

 

[dank GN]

Did you replace the rear wheel cylinder with the bigger 15/16th upgrades cylinders? They are off a 95 s10 with manual brakes and is a cheap upgrade that will allow u to hold more boost at the line

 

[michael evans]

No special tools needed to remove the axles. Just a little patience (now I hear the song)

After you take the brake parts off, loosen the steel line first then you can use a straight-blade-screwdriver to pop off the retaining ring for the cylinder.

Take the off the four bolts that hold the backing plate to the housing.

Depending on which size of cylinder is what socket you use to attach it to the backing plate.

 

[DOG]

No i just went with OEM replacements from the auto part store, i could probably return them but what would i be looking for?

I successfully accomplished to remove the axle and backing plate, but I am having trouble removing the parking brake from the backing plate (any recommendations).

I discovered i have a Posi rear end, so does anybody have a good recommendation on what fluid i should put in the rear diff?

 

[michael evans]

A boxed in 13mm wrench is how I did it.

 

[dank GN]

You get the wheel cylinders from a 95 s10 with manual brakes . It is bigger then the stock one so it can apply more braking force and it fits right in place

 

[GNTIM]

You get the wheel cylinders from a 95 s10 with manual brakes . It is bigger then the stock one so it can apply more braking force and it fits right in place

Can also cause problems with the rear tires locking up. If he didn't know that he has a posi, I doubt he races it.

 

[dank GN]

Can also cause problems with the rear tires locking up. If he didn't know that he has a posi, I doubt he races it.

I have never had issues with the rear tires locking up . I have herd about that issue and believe it’s because ppl ha e replaced the actual brake shoes with the 2 longer shoes .

 

[DOG]

Well i compared my original wheel cylinders to the S10 wheel cylinders, and i discovered that the bigger ones would not fit right in place. The bigger ones had two additional screw hole adapters (no idea where that would go) and the bracket on the back was not identical to the OEM.

I successfully removed the axle and now I am back to my original problem, with a brand new backing plate installed I still cannot get the round (C clip clamp with the wings) to secure on the back of the wheel cylinder. does anybody have a trick on how to get that stupid thing to secure. I'm pretty sure i need some kind of specialty pliers to complete this job. i have gotten to the point where i use a giant C-clamp to keep the wheel cylinder in place, and then i have tried everything i could think of to marry this clip to the cylinder with no luck. does anybody know how i can get that retainer clip to seat.

This website explains what im going through but doesnt tell me the tool requried.

https://www.brakebleeder.com/gm-clip-wheel-cylinders/
Thank you for all your time.

 

[michael evans]

Open the C-clamp up so you can fit the cylinder and the correct scocjet ( 1 1/8” for a stock) and squeeze it it in place.
It may take three hands to hold everything in place.

 

[michael evans]

Could not get a scocket to work on the S-10 cylinders I used, so I made a fitted tool on my lathe.

Not hard tomake but I “loaned” it to Brad at Boostcrew about two years ago.

 

[DOG]

The stupid O clamp with wings, that secured the wheel cylinder was the worst part of this whole project. I ended up removing the backing plate and using 2 screw drivers to push it flush (evenly) then my buddy to another screw driver with a small hammer and we finally secured it.
We put everything back together and bled the system the best we could, but my brake pedal is very spongy. I think we are going to put it on his lift and do a vacuum bleed to make sure there is no air.
thank you all for your time