Drum Upgrade Question

Hey All,

I don't really have the luxury of being able to work on my CJ at my condo, but there is a place nearby where I can rent a full bay w/ lift for an entire day so that's what I usually do. Planning on doing a bunch of things this weekend, one of those being overhauling my rear drums (cylinders are leaking and the drums (and likely internals) are rusted to hell).

Here's my question. Without being able to take my wheel/drum off and measuring the interior at my condo, I took a rough measurement of the exterior and ordered parts for 11" brakes. In the event, I pop open the drum and discover I was wrong and they are 10", is there anything preventing me from just installing/upgrading to the 11"? Also, what parts would I be missing to do so, besides the backing plates? I have a Dana 44 rear axle.

Here's a list of what I have already from Rock Auto:
BOSCH BS228R Brake Shoe
RAYBESTOS H7137 Drum Brake Hardware Kit x2
RAYBESTOS H2541 Drum Brake Self Adjuster Repair Kit
RAYBESTOS H2540 Drum Brake Self Adjuster Repair Kit
RAYBESTOS 2307R Drum
RAYBESTOS WC370192 Wheel Cylinder
RAYBESTOS WC370193 Wheel Cylinder

Also, if this is a completely dumb question, I'm not a gear head (but learning) so feel free to tell me to go pound sand.

 

If you have the 11" backer plates and all the hardware plus the wheel cylinder and shoes, bolt em on.. If you don't, you can't just use 11" parts with 10" backer plates and hardware to make it work.

 

That's exactly what I needed to know. I've bought all hardware (cylinder, shoes, etc) for 11". The only thing I didn't purchase was new backing plates so if they end up being 10", I'll just get the 11" plates. Thanks!

 

If it's an unmodified '73, it has 11"x2" Bendix drum brakes. I had to look in your profile for that info - it would be helpful to add it to your signature file so it's in every post.

I don't know that there is a source for new replacement backing plates. They are not something that wears out normally.

The aftermarket suppliers are sometimes clueless about which parts are correct for which year range of Jeeps. Until you know more, it's good to ask like this.

Those parts look fine. I don't have a parts book for 1973, but my 1974 book will be the same. It says the rear cylinders are 15/16" diameter. Realize that the self-adjusters are handed, ie one is left handed threads and the other is right handed. Be sure to put them on the right side. The TSM has a picture for you to follow, and also test that the self-adjusters work. When you pull on the cable so the lever climbs the toothed wheel, you release and the lever turns the toothed wheel. This should make the self-adjuster longer, moving the shoes out.

You may need to loosen your parking brake adjustment. I would leave the parking brake kinda loose until I had done the go in reverse - apply brakes routine to adjust the new brakes.

 

Your self adjusters may be frozen. Real common to happen. Make sure to spoon them together if you can to get your drum off. If you can't, it's going to be annyoying. If they are ok, take them apart and put some anti seize on the threads.

 

Thank you both! Hoping they are 11x2 because as you mentioned, I took a quick search online and it’s gonna be a little bit of a mission to track down new backing plates. Will report back this weekend!

 

Also, my parking brake has never worked so gonna try to tackle that as well.

 

Success! Everything went smooth. They were in fact 11x2 so everything fit perfectly. New drum, shoes and all new hardware. Left side wasn’t leaking too bad, but right side was completely covered in brake fluid.

Also replaced my master cylinder.

Question for you guys...when bleeding the brakes, the rears would shoot fluid up out of the master cylinder when pumping the brakes, as expected, but the fronts (discs) didn’t move the brake fluid in the master cylinder at all. Additionally, when bleeding the fronts, fluid would squirt out the bleeder nipple during the first pump, but then only trickle for every pump after that. Is that normal? They seem to be stopping just fine.