Rear Brakes binding??

Fullchat289 · #1 (**permalink**) 08-12-2010, 09:20 AM

Since taking receipt of No.2124, there has always been excessive brake dust on the rear wheels relative to the front. Even the original owner pointed this out to me. I have had a suspicion that the rear brake pads are running a little too tight against the rotors and I believe this to be correct due to the temperature difference I can feel between the front and rear spinners after a drive. The car will coast just fine, and I don't have a problem pushing the car out of my garage (something I do prior to start-up) so they aren't binding "bad", but I suspect there to be contact between the pad and rotors in the "free" state. Both sides exhibit the same amount of brake dust and feel similar in temperature. As far as checks go, I've thought of the following:

- Check Parking brake adjustment when fully disengaged
- Bleed Brakes
- Check Balance Bar adjustment.

Can anyone think of anything else or relate to this situation in general??

Thanks in advance,

- Allen.

Jerry Clayton · #2 (**permalink**) 08-12-2010, 10:17 AM

do you have residual valves?

Fullchat289 · #3 (**permalink**) 08-12-2010, 11:07 AM

Jerry:

Not that I am aware of...I'm not sure they are typical on an ERA...

- Allen.

patrickt · #4 (**permalink**) 08-12-2010, 11:20 AM

Allen, I take it you have the outboard braked rear. The PBR brakes have a "parking lever adjuster screw" on the back of the caliper that you would never find unless you knew it was there. But before you even think of screwing around with it, check and make sure that your parking brake lever on the caliper is releasing fully and not dragging. Here's a pic, do you see how the cable pulls the lever? It should release fully and not be tight when the brake is off.

strictlypersonl · #5 (**permalink**) 08-12-2010, 11:23 AM

No RPVs for more than 15 years.

I suspect that the problem is not dragging at all, but pads that are not exactly "dust free".

Is this the ERA or Jag rear?

Check the balance bar for proper orientation and/or binding.

ERA rear:
Check that the caliper is centered on the rotor, and free on the pins.

patrickt · #6 (**permalink**) 08-12-2010, 11:37 AM

Allen, if your parking brake isn't obviously dragging, then check the stuff Bob P. mentioned, and then just replace your pads with some quality stuff, and then check your free travel as per below:

Fullchat289 · #7 (**permalink**) 08-12-2010, 11:51 AM

Everyone, thanks for the information. Patrick, as usual, very helpful...

From that diagram you posted, I'm wondering what the smaller springs are for that are adjacent to the measurement point "B". I do remember from having the wheels off just recently that the one end wasn't connected to anything.....wonder if we are on to something here... Are they return "helper" springs for the caliper pot?

But in any case, I'll get the rear of the car off the gound this evening when I get home and apply a few of these checks..

PS: yes, I have the ERA rear.

- Allen.

patrickt · #8 (**permalink**) 08-12-2010, 11:52 AM

Quote:

Originally Posted by Fullchat289

Everyone, thanks for the information. Patrick, as usual, very helpful....

Take that, Chas.

Fullchat289 · #9 (**permalink**) 08-12-2010, 11:55 AM

Quote:

Originally Posted by patrickt

Take that, Chas.

Poor guy gets dragged into every thread, doesn't he??

- Allen.

ERA Chas · #10 (**permalink**) 08-12-2010, 12:03 PM

Quote:

Originally Posted by Fullchat289

Poor guy gets dragged into every thread, doesn't he??

- Allen.

Allen,
Follow BOB's advice- he designed the thing.

Carnac only shows-off his photo skills at the drop of a turban...

And remember who answers the phone at ERA-it ain't our boy here.

patrickt · #11 (**permalink**) 08-12-2010, 12:04 PM

Quote:

Originally Posted by ERA Chas

And remember who answers the phone at ERA-it ain't our boy here.

In time, in time....

patrickt · #12 (**permalink**) 08-12-2010, 12:08 PM

Oh, and I'm still working on a particularly cool upgrade to my car....

Fullchat289 · #13 (**permalink**) 08-12-2010, 12:14 PM

I will take Bob's advice into account for sure.. but my line of thinking was in-line with Patrick's suggestion as the ERA rear was assembled by the previous owner and I figure since he has always had the excessive brake dust issue and the spinners are "warm" after a drive relative to the fronts, I suspect there could have been some error made in adjustment.

But to respond to a previous suggestion, yes, I've made sure that the e-brake lever is in the fully released position.

Can anyone respond to what the two little coil springs are as shown in the diagram? Are they "helper" springs for the pot as I suspect? I know that one of them on the passenger side isn't connected to anything on one end of the spring..

- Allen.

patrickt · #14 (**permalink**) 08-12-2010, 12:42 PM

Quote:

Originally Posted by Fullchat289

Can anyone respond to what the two little coil springs are as shown in the diagram? Are they "helper" springs for the pot as I suspect? I know that one of them on the passenger side isn't connected to anything on one end of the spring..

I think so. Go to the owner's page on ERA's site, then go to the Manual Supplement page, then look under "Brakes" and click on Pad Replacement, Rear GM. That will open up a PDF that shows the overhaul of the caliper and pictures of those little springs, like this:

patrickt · #15 (**permalink**) 08-12-2010, 12:53 PM

Quote:

Originally Posted by Fullchat289

I know that one of them on the passenger side isn't connected to anything on one end of the spring...

Uhh, I think we could get Chas. to opine on whether or not a spring does anything if it's only hooked up on one end....

Fullchat289 · #16 (**permalink**) 08-12-2010, 01:31 PM

hmmmm...Parking Brake collar return springs... I'll update this thread with what I find when I can pull the wheels off later this evening. Thanks again for the info and reminder of the suppliment pages on the ERA site!

- Allen.

Excaliber · #17 (**permalink**) 08-12-2010, 06:25 PM

Quote:

Oh, and I'm still working on a particularly cool upgrade to my car....

Patrick has a Skunk Works shop???

patrickt · #18 (**permalink**) 08-12-2010, 06:27 PM

Quote:

Originally Posted by Excaliber

Patrick has a Skunk Works shop???

Ha! I thought that said "skank."

Fullchat289 · #19 (**permalink**) 08-13-2010, 09:29 AM

Well, turns out everything checked out OK last night. Put the car up on stands, pulled the two rear wheels and did a visual of the rear calipers and checked the adjustment of the e-brake cable. Turns out the hook on the end of the tension spring for the e-brake collar isn't supposed to really connect to anything...the tab on the collar actually sandwiches in between the coils of the tension spring...which seems strange to me. Confirmation of this can be seen on the .pdf file on ERA's website for brake caliper replacement/reconditioning. So working my way up the car, I pulled the cover for the master cylinders and aside from the fact that my front and rear master cylinders were swapped relative to ERA's diagram for balance bar adjustment, all appeared fine there as well. The balance bar was biased the recommended amount to the rear master. So for now, I'll just keep an eye on the position of the e-brake handle - making sure it is fully in the released position. My car has a Series 1 Jag handle and I found that at it's absolute lowest position, the button of the handle remains pushed in. The claw that rachets on the e-brake rack must be riding on the beginning of the rack in this position. I'll remain concisous of this while driving and see what my hand senses on the rear spinners after my next run.

So the cliffs notes version is I didn't find anything amiss..

- Allen.

patrickt · #20 (**permalink**) 08-13-2010, 09:33 AM

Quote:

Originally Posted by Fullchat289

So the cliffs notes version is I didn't find anything amiss..

That's good. Are you going to change the pads?