touchy brakes

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May 12, 2022 | 07:36 PM

#31

AuroraGirl

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Quote:

Originally Posted by gccch

I have not done anything to the RABS except to bleed the port on it as well as all other bleed points.

Rear brakes are not locked up. They are just activating too soon - mostly on driver side. They spin freely when no brake is applied. So I guess I am having a hard time understanding how they would spin freely but also hanging up? Do you mean there is not enough "play" in the rear brakes that they are grabbing too soon? Maybe I should adjust them loose?

Quote:
Originally Posted by SFaulken View Post
Could be a rotten softline between the frame and axle in the back. Could be a wheel cylinder that has crap in it, and is hanging up the system, could potentially be a bad residual valve on the rear brake circuit, that isn't releasing. I can't recall if the residual valve on these trucks is built into the port on the master cylinder, or if it's down in the proportioning valve.

You should try that line on the axle and flush the metal lines going to each side. debris was in mine. and also, that valve on the MC i posted the pic of, thats the one controlling when/if the rear gets full pressure. go get her

May 13, 2022 | 02:58 AM

#32

gccch

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Mountain Pass

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From: Mass.

Quote:

Originally Posted by AuroraGirl

Thanks. I did the valve on the master already. I'll go for that last flex line next.

May 15, 2022 | 04:59 PM

#33

gccch

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Mountain Pass

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From: Mass.

I think I solved it! Still need to bleed the rears again, but the flexible hose to the differential seems to have been the culprit. Would have done this at the same time as the fronts but I forgot there would be one in the rear. Thanks to reminders on here I got to it and the "bite" is so far gone. Brakes are totally better even before bleeding out the rears.

May 17, 2022 | 02:38 PM

#34

gccch

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From: Mass.

Not really solved. I think my shoes are grabbing when cold. It has to be temperature at this point. Once I stop a few times they are less grabby. I'm putting new linings on my list.

May 18, 2022 | 01:23 AM

#35

AuroraGirl

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Quote:

Originally Posted by gccch

Not really solved. I think my shoes are grabbing when cold. It has to be temperature at this point. Once I stop a few times they are less grabby. I'm putting new linings on my list.

how old are they and how do they look wear wise? did you have the primary/secondary shoe on the right side, is the adjusters on the right side?

also, grabby may mean you have air in your circuit. imagine if your fronts dont grab because compression from air, but the rear are perfect and ready to go.

they will be grabby. also, springs weak?
severely worn rub points on the backing plates?

Jun 4, 2022 | 03:51 PM

#36

gccch

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Mountain Pass

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From: Mass.

Quote:

Originally Posted by AuroraGirl

I changed the shoes on the side that was grabbing the worst and whalla! now the other side is chirping a bit. The lining must have been hardened or old, or contaminated or something. Major difference right away. Should have tried that earlier. Been chasing hydraulics for no reason. At lease I have clean fluid and good rubber lines now.

Jun 4, 2022 | 04:38 PM

#37

AuroraGirl

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Quote:

Originally Posted by gccch

You should do the brake linings at the same time the drums work together to be equal, one doing more work will quickly overheat or wear one out and then they dont have the same braking characteristics

Jun 5, 2022 | 07:58 PM

#38

gccch

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Mountain Pass

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From: Mass.

Quote:

Originally Posted by AuroraGirl

Yep. I got to the other side today. It's been pouring rain for a few days. All is well now. Even better with both sides smoothly braking. No lock ups.