Re: IML: 69 Lebaron brakes pulling

This is Shaun from DuraBrake and i can only give my opinion on the rotors as I am definitely not an expert on any of the other components. From the best of my knowledge I believe that this amount of runout should not cause this problem. In response to the literature that says to not turn these rotors I have found the following information about other Chryslers that might help you

http://www.allpar.com/history/mopar/disc-brakes.html

"Factory literature of the period stated emphatically that these rotors were not to be machined thinner, but replaced if the grooving made the rotor unuseable. Research, however, has uncovered the reason for that statement: the factory had little confidence in the ability of the lathes then in use to properly maintain runout and thickness variation specs. Today, however, every garage has equipment capable of easily maintaining those tolerances, so machining is now considered acceptable."

This was for A-body rotors but I assume that the conclusion would be the same that not turning rotors was only suggested because of lack of capabilities of machine shops.

Hope this helps

Shaun

From: "john sadowski" <jsadowski@xxxxxxx>
Reply-To: mailing-list@xxxxxxxxxxxxxxxx
To: <mailing-list@xxxxxxxxxxxxxxxx>
Subject: Re: IML: 69 Lebaron brakes pulling
Date: Sun, 22 Jul 2007 15:48:00 -0700

If you notice in the service manual that it says the rotors must not be turned. Some think this is B/S & any rotor should be able to be turned.

Just thought I'd point that out.

John

----- Original Message -----

From: DickB@xxxxxxxxx

To: mailing-list@xxxxxxxxxxxxxxxx

Sent: Sunday, July 22, 2007 10:41 AM

Subject: RE: IML: 69 Lebaron brakes pulling

I?m not a brake expert, but the run out measurements seem fine to me ? I certainly would not suspect that amount of run-out to cause a problem. I do notice that you don?t mention changing the brake hoses ? and those can certainly cause a brake to fail to release completely. They seldom fail by bursting, they do very often fail by developing blockage which does not affect the application of brakes (the pressure is so high that it blasts through any restriction) but the blockage will prevent the brake from releasing completely (much less pressure in that direction). This has come up before on the IML ? and it is repeated here ? always replace all 3 (yes, 3) brake hoses when you do any brake work ? it?s cheap insurance against this sort of problem.

Dick Benjamin

From: mailing-list-owner@xxxxxxxxxxxxxxxx [mailto:mailing-list-owner@xxxxxxxxxxxxxxxx] On Behalf Of Frederick Joslin
Sent: Sunday, July 22, 2007 9:34 AM
To: mailing-list@xxxxxxxxxxxxxxxx
Subject: IML: 69 Lebaron brakes pulling

I recently replaced the entire braking system on my 69 LeBaron Coupe. Yesterday was my first chance to drive the car.

This is always an exciting proposition after major brake works has been done, even if you are sure that everything was done correctly.

Everything looked good and worked great. The car stopped well and the pedal feel was firm and high up. The only problem is that the car pulls to the left.

I replaced the master cylinder all wheel cylinders (CalipersOnline calipers at front), pads, shoes and front rotors (Dura Brake).

After I had completed the assembly I checked the run out of the rotors. The DS was 0.007" and the PS was 0.003" and the DS front wheel is noticeably more difficult to turn than the PS front wheel. Is this causing the pulling?

If so it seems that the remedy is to have my brand new rotors turned to make them more true. Not what I had anticipated!
Fred Joslin