What is wrong with my brakes

[Joeyk94]

OK so ever since i put this new rear end in, everything was going great about 2 months ago my passenger side slack adjuster backed in and brake cylinder piston ejected. Fixed it. A Christmas eve the driver side did the samething. Fixed it. Tonight it did the same thing. Every time is doing it the piston is poping out and draining the brake fluid and the master cylinder goes dry so I have to replace it and bleed the brakes. What is going on here? This is becoming a big Hassel and I'm over drums now because of it.

Sent from my SM-G900T using Tapatalk

 

[Joeyk94]

You must be registered for see images

You must be registered for see images

You must be registered for see images attach

You must be registered for see images

Sent from my SM-G900T using Tapatalk

 

[Jrgunn5150]

Are you adjusting them until the drums drag? Have you replaced the springs and hardware?

 

[Joeyk94]

Yes I'm adjusting them until they drag. Everything was new when I put the rear end in the truck 6months ago

Sent from my SM-G900T using Tapatalk

 

[Jrgunn5150]

I'm out of idea's, other than replace the wheel cylinders.

 

[east302]

Are these duo servo brakes the ones that came with the truck or was it originally leading trailing type? If it originally had leading trailing style (RPO code JB5) then let us know what all you changed.

Are these the correct wheel cylinders? I know they had at least two variants depending on drum brake style.

Looking at a Haynes book, it looks like they hooked the two top return springs differently. Not sure if it matters but here it is...

You must be registered for see images attach

Their #10 hooks "up" at the center where yours faces down if that makes any sense.

Their #9 faces down where it hooks to #8 where yours faces up.

Granted, the book picture is for the opposite side, so it's a mirror image and I could be wrong here.

Last, do the duo servo spring and hardware kits differ from driver to passenger side? Make sure you put the right one on if that's the case.


Sent from my iPhone using Tapatalk

 

[michael hurd]

You must be registered for see images

You must be registered for see images

You must be registered for see images attach

You must be registered for see images

Sent from my SM-G900T using Tapatalk

Looking at the picture, it seems to me that the adjuster is screwed tight, and the wheel cylinder over extended. There are left and right adjusters, perhaps you have them swapped from side to side and with normal use they are backing off instead of ratcheting tight when backing up and braking.

The top of the left hand shoe is not contacting the anchor pin at the top. It's been a while since I looked at a 10 bolt backing plate.

It is also very possible that someone has purchased the adjusters previously, swapped boxes and returned them in the wrong box. ( I used to work at an auto parts store... and U-joints were a common mixed up item like that )

 

[Joeyk94]

The RPO code is JB5. I got this rear end from a 98 suburban. I went and bought all new stuff (drums shoes springs adjusters and wheel cylinders) for each side. I went off a Google image when I put everything back together so I will see how this goes this time around

Sent from my SM-G900T using Tapatalk

 

[east302]

Your truck came with the 10" drums but since you've replaced everything in the back to 11" then it shouldn't matter. The master cylinder is the same across the line, but I'm not sure if the brake combination valve at the abs unit is the same or not. It probably is.

It's probably a hardware issue like Michael suggested. Double-check the spring orientations, the way that they're hooked on is probably key. I'd buy new spring and adjuster kits and try again. It may help to take a few pictures when it's done so we can see the "before" if it comes apart on you again.




Sent from my iPhone using Tapatalk

 

[Jacob]

Are you sure you put the adjusters and hardware in the right way? If backward they would loosen going forward instead of tighten when backing up I think.

It also looks like the shoes are the wrong size for the backing plate.