Author Topic: Help with rear disc brakes!!  (Read 17917 times)

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Offline eroc022

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Help with rear disc brakes!!
« Reply #15 on: July 29, 2012, 12:28:30 PM »
Take the emergency/parking lever off and rotate the std with a 9/16 wrench, then put you lever back on with the lever in the "released" position and reconnect everything
Eroc
Fixing the car that Restore A Muscle Car jacked up....

Offline mattblack84

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Re: Help with rear disc brakes!!
« Reply #16 on: July 30, 2012, 12:23:50 PM »
ok and if the 9/16 nut is not turning or hard too is there a way to sort of loosen it?  Or is it time for a rebuild?

Offline eroc022

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Help with rear disc brakes!!
« Reply #17 on: July 30, 2012, 12:29:50 PM »
Should turn one way or the other, one will back the pad from the rotor the other will push it towards the rotor if it's not turning, I would say new calipers or rebuild yours
Eroc
Fixing the car that Restore A Muscle Car jacked up....

Offline mattblack84

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Re: Help with rear disc brakes!!
« Reply #18 on: September 07, 2014, 01:18:18 PM »
ok so an update bought new rear calipers, pads.  everything went in ok but still soft pedal and after fighting to get it adjusted the brake light comes on radomly.  Does anybody know how to even get this damn thing adjusted or have the procedure I read the one in the service manual and it dosent make sense so im kinda getting confused and frustrated at the same time........

Offline Angelo

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Re: Help with rear disc brakes!!
« Reply #19 on: September 07, 2014, 01:42:05 PM »
I suspect the prop valve, hose ballooning or a leak.
81' ex-Turbo Trans Am - Resto-mod

Offline mattblack84

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Re: Help with rear disc brakes!!
« Reply #20 on: September 08, 2014, 09:10:50 AM »
Checked this morning no leaks or hoses ballooning do you think there might be air in there ?  I'm going to try bleeding the car again and let you know.

Offline Angelo

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Re: Help with rear disc brakes!!
« Reply #21 on: September 08, 2014, 10:36:00 AM »
Air would make your brakes spongy, you would notice that right away. The reasons that cause the brake line to come on:

* Emergency brake set
* Leak in system
* brake line taking up too much of the pressure (brake hose ballooning)
* A lot of air in the brake system somewhere (if it's excessive to one of the front calipers, you would feel the car pulling to one side or the other during braking, this will at least narrow down this particular symptom to the front or rear brakes.)
* Proportioning valve not working correctly.

The prop valve is what turns the brake light on (other than the emergency brake). I would not suspect the booster or master cylinder, though others with more experience may if they have encountered some weird situation that could explain it.
81' ex-Turbo Trans Am - Resto-mod

Offline Angelo

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Re: Help with rear disc brakes!!
« Reply #22 on: September 08, 2014, 10:39:29 AM »
Do you trust your friend who checked that the hoses were not ballooning when you pressed the brakes? Or did you have a friend press the brakes and you observed that the hoses were not ballooning? Not saying whom ever is helping you can't be trusted, but they may not understand what you are looking for with the hoses. It is not going to balloon out like a kids balloon, you're looking for the hose changing shape (getting larger) when the brakes are applied.
81' ex-Turbo Trans Am - Resto-mod

Offline mattblack84

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Re: Help with rear disc brakes!!
« Reply #23 on: September 08, 2014, 04:08:57 PM »
Well me and my dad bled the brakes and found the emergency brake on the passenger side wasn't working right took off the caliper reworked it got it to ratchet out rebled the brakes and the car is stopping great got a nice pedal looks like problem solved.

Offline Angelo

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Re: Help with rear disc brakes!!
« Reply #24 on: September 08, 2014, 04:30:34 PM »
That could do it. BTW Make sure you use the emergency brake regularly, it is required for the rear caliper pistons to adjust.
81' ex-Turbo Trans Am - Resto-mod

Offline randr

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Re: Help with rear disc brakes!!
« Reply #25 on: November 15, 2014, 07:44:58 PM »
  I think I'm having the same problem with my rear calipers.  No matter what I do the brakes feel spongy. No leaks, Vacuum bled 4 times and bench bled 4 times. I'm sure it's not recommended, but someone tried telling me to eliminate the e-brake and that front calipers should bolt right on to the rear? Anybody ever hear of this? Also anybody have a link to the proper procedure to adjust e-brake? Could it also be that I vacuum bled my brakes without using that PV bleeding tool that was show earlier in this thread? If so how can I re-center the proportioning valve and where can I get one of those tools? Thanks.
« Last Edit: November 15, 2014, 08:06:14 PM by randr »

Offline Angelo

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Re: Help with rear disc brakes!!
« Reply #26 on: November 15, 2014, 09:00:24 PM »
80's s10 front calipers bolt right up to the rear. Same brake pads as well. You will have no e brake, so if you plan on doing any racing that requires it like autocrossing you will want to keep the ebrake.

If swapping to non ebrake calipers solves your problem then either your ebrake calipers aren't ratcheting properly or you never adjusted them before bleeding. Its pretty easy though, first you get the ebrake working then you bleed the brakes. If the ebrake is never adjusted though then those calipers will never be close to the rotors and would explain a lot with the braking condition.
81' ex-Turbo Trans Am - Resto-mod

Offline randr

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Re: Help with rear disc brakes!!
« Reply #27 on: November 16, 2014, 09:30:49 AM »
Thanks. I'll try adjusting the e-brake again before I do anything rash. It's an automatic and I don't plan on  racing.  As matter of fact I don't think I ever even used the e-brake. What about bleeding without using the prop tool? Could that be causing problems?

Offline Angelo

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Re: Help with rear disc brakes!!
« Reply #28 on: November 16, 2014, 10:16:59 AM »
Prop valve?

'Prop tool' there's no specific tool needed to bleed brakes, There are many ways which seem specific to every mechanic. I use name brand speed bleeders myself, its a bit voodoo to most.
81' ex-Turbo Trans Am - Resto-mod

Offline randr

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Re: Help with rear disc brakes!!
« Reply #29 on: November 16, 2014, 11:01:55 AM »
Sorry. Maybe I wasn't clear. I was talking about the proportioning valve tool that there is an image of on the 1st page of this  subject.