P15 dragging the rear brakes?

[Slickster]

New to me P15, '48, runs well, first time out on road, car stops by itself at slow speed, definitely binding up, both rear drums are warm, driveshaft spins freely with E brake released, jack it up, wheels spin with effort backward,do not spin forward, seems brakes are tight, backed off external adjuster, no change, brake pedal freeplay at 1/2 inch....waiting on drum puller tool...any thoughts, seems both sides are binding, btw, appears like PO has been into entire brake system...

[Doug&Deb]

Stupid question but did you back off adjusters for both shoes on each side? Sounds like an adjustment problem but check for leaking wheel cylinders also. Check the technical archive for information on how to make an adjustment tool. The correct tool is almost impossible to find. 

[Slickster]

I backed off the external adjuster, no change, don't have drums off yet, waiting for puller....seems the adjustment procedure is crazy with multiple measurements and special tools....on the front, I sanded down the linings with a beltsander until I could barely get drum on without binding, worked great, good brake feel and action

[squirebill]

See if the rear brakes are binding because the hydraulic pressure of the system is not releasing.  Open one of the rear brake bleed fittings to relieve any retained hydraulic pressure.  If the wheels then spin freely you probably have a hydraulic system problem. Regards

[Sam Buchanan]

3 hours ago, Slickster said:

I backed off the external adjuster, no change, don't have drums off yet, waiting for puller....seems the adjustment procedure is crazy with multiple measurements and special tools....on the front, I sanded down the linings with a beltsander until I could barely get drum on without binding, worked great, good brake feel and action

Be sure you completely  understand the brake adjustment procedures before performing surgery! These brakes are unlike anything on modern cars and require careful study of the manuals to understand how all the adjustments interact.

 

Here is an article from the Tech section of this forum to get you started:

 

https://p15-d24.com/page/p15d24/tech/brakes.html/

Edited November 12, 2020 by Sam Buchanan

[Slickster]

I did open the bleeder, no change...I've read several of the threads on repairing the brake system, one thing was clear, the thickness of the lining was way too thick to ever get the drum back on, looked like 1/4, OEM is 3/16?...that's about what I removed....stops straight easily...

[squirebill]

Confuses me that the drive shaft spins freely when E brake is released but rear brakes are dragging. 

[martybose]

Both times that you have mentioned the brake adjustment you said "the brake adjuster", singular.  These shoes have a separate adjuster for each shoe, that is what makes them so difficult to get right.

 

Marty

[Slickster]

Sorry....the driveshaft isn't bound up by the e-brake, it is easily rotated 1/4-1/2 turn, I realize there are 4 adjustment points, the two external ones don't make any difference no matter what direction I rotate them...seems the PO or someone has been into the brake system, both rear axle nuts we EASILY loosened, estimate 25 ft lbs to remove, one side missing cotter pin....backed off nuts and went for drive around block, drums didn't move....waiting for puller...the plot thickens...