The Stovebolt Site Forums The Parking Lot Tons 'o Fun Rear brake photo/dilemma

Does anyone have a photo of the rear brake assembly for an AD 1ton? I have a 1952 GMC (Canadian) 9433 which is the same as the 250-22 as far as I know and has 14" drums and the 8 bolt hubs. I have spent hours trying to get the rear drums off. I've managed to get one almost 1/2" off, the drum still turns with some drag but it won't come off. I was using a 7 ton "three leg" puller, removed the brake line, bleeder valve, backed off the two pinion adjusters, managed to undo the nuts and bolts for the park brake and even popped 6 of 8 studs back in with a rubber mallet to reduce any hang up. ( that in itself is a bit weird) I've used heat, pry bars against the back plate, wiggled, pulled maybe even cussed and had a beer without luck.
I'd like a photo to see what/if I can hook or hit anything inside to help free it the rest of the way. It's hard to imagine the rust ring stopping all this.. For what it's worth, the young guy I bought this from last year said he replaced all the brake shoes but had never seen drum brakes before, and they didn't work at all then.
Any ideas before I get the cutting torch out would be most welcome!

You haven't mentioned removing the 2 screws on the face of the drum that hold it in place. As for the pinion adjusters, they are very fragile and although they may be turning they may not actually be loosening the shoes. I've had to press on the shaft of the pinion with a big screwdriver, forcing it in towards the outside of the drum while turning carefully with an open end wrench in order to adjust the shoes. Be careful with those drums as good ones are hard to find.

Thanks - the first thing I did was remove the screws. The drum is 7/16"- 1/2" off the hub and still rotates with a bit of drag: that's the part that really stumps me. I'll try fiddling with the pinion adjusters as you described and see what develops.

Hy Thornfield, welcome, all drum brakes that I have ever worked on have had a ridge develop on the inboard edge of the brake drum. In order to remove the brake drum you must back the brake shoes back down so that the ridge on the brake drum will clear the brake linings. As has been stated previously the brake shoe adjusters are fragile and don't always back the brake shoes down, that may be the case here. If that is the case then using whatever force is necessary to pull the drums off over the brake linings may be all you can do, understand that this procedure will damage something somewhere in the braking system. One thing you might try would be to undue the bolts that hold the wheel cylinders to the backing plates, cut the hydraulic line and drive the wheel cylinders into the backing plate, that action might result in the brake shoes collapsing in a bit. Hope that helps, good luck.

Thanks - just got in from the barn after successfully removing the drum! I managed, as you said, to drive the wheel cylinder down and free of the shoes. I guess that gave me the fraction I needed to get them clear of the ridge line and off with the drum. Also, as Eureka Jim mentioned, the pinions are/were delicate as I found them in the bottom of the drum where it appeared they had been for some time.
The wheel cylinders were seized up real good and it was obvious the shoes had never been arced to the drum. Maybe I'll drill some conventional access holes with rubber plugs to adjust the replacement set up.
Thank you again for the advice guys - time for a beer and on to drum number two...

Been there done that. My drums were so worn the shoes were trapped in the drum. I ended up bending one of my shoes trying to get the drum of. I have since found 1 NOS drum, just need one more to carry on. They are extremely hard to find.

Sometimes it is easier and less $, to go with an appropriate GM ff 14 bolt, higher ratios, too.

Ed

I would have suggested undoing the hub bearings so that whole assembly has more freedom to move. If you use too much force you could damage a drum and that would be very unfortunate.