Attention: TDR Forum Junkies 
Thought I'd post my recent experience with the drum system on my truck in case there's more guys out there that are in the same position I am (was).
Background: I had paid big bucks a few months ago having the fronts redone and I was worried that they'd be trashed again soon from the back ones not working well. So I did a lot of research on the TDR and the first step was adjusting the star wheels on the brakes. Seemed to help some but still not the level of performance I was comfortable accepting. So, I ordered bigger wheel cylinders and new shoes.
Today I put a new set of shoes on the back as well as new and slightly bigger cylinders on each rear wheel in hopes of getting some stopping power to the rear. After doing that I was still unhappy with the performance. It just didn't seem right. At this point I really got an eye opener... ...
I put the truck up on jack stands, started it up, put in gear and let it idle. Then I pushed down on the brake pedal and guess what..... that's right, the wheels kept on rollin'
Sometimes, they'd act like the shoes were pressing against the drum but not enough to stop the motion. At this point I put it in neutral and let the wheels spin slow and lightly; step on the brake and both wheels stop. Hmmm. I knew I had cylinder actuation, had them shoes adjusted to slight drag, and knew the lines were well bled. Back to the TDR search forum... ...
I remembered reading posts about the rear height sensing load proportion valve and a TSB for some trucks. Boom, found many posts and read in a few places where folks disconnected there proportion valve rod and tied it up so the valve was in the full open postion; figured that was worth a try. I popped off the lower mount point of the rod, tied it up and tried the in-gear/on stands test again. Result: Great and immediate wheel stoppage every time I pushed down on the pedal.
I'm going to drive it for a few days to make sure I don't get wheel lockup but I have a feeling I'll be getting rid of the proportion valve via the TSB part. There are also posts about leaving the rod in and making it adjustable. My truck is probably like most in that it's already meeting the operating at 75% GVW recommendation/suggestion of the TSB without having a load or having the trailer hooked up.
Conclusion/Recommendation: Those of you who have rear wheel drum brakes I would suggest you try the break test I did (on the jack stand test). I was already doing the jack up and adjust star thing but with little to no fluid pressure getting back to the cylinders it was pretty much not helping anything. It was watching the wheels still turn with the brake depressed that opened my eyes.
The bad news is I probably didn't need new cylinders and my old shoes where hardly worn (but cracking in places). The good news is clyinders are real cheap so I'm not really out much there and the even better news is the rear brakes are actually doing something at the present time.
Hope this post helps someone else out.
Rich
Background: I had paid big bucks a few months ago having the fronts redone and I was worried that they'd be trashed again soon from the back ones not working well. So I did a lot of research on the TDR and the first step was adjusting the star wheels on the brakes. Seemed to help some but still not the level of performance I was comfortable accepting. So, I ordered bigger wheel cylinders and new shoes.
Today I put a new set of shoes on the back as well as new and slightly bigger cylinders on each rear wheel in hopes of getting some stopping power to the rear. After doing that I was still unhappy with the performance. It just didn't seem right. At this point I really got an eye opener... ...
I put the truck up on jack stands, started it up, put in gear and let it idle. Then I pushed down on the brake pedal and guess what..... that's right, the wheels kept on rollin'
Sometimes, they'd act like the shoes were pressing against the drum but not enough to stop the motion. At this point I put it in neutral and let the wheels spin slow and lightly; step on the brake and both wheels stop. Hmmm. I knew I had cylinder actuation, had them shoes adjusted to slight drag, and knew the lines were well bled. Back to the TDR search forum... ... I remembered reading posts about the rear height sensing load proportion valve and a TSB for some trucks. Boom, found many posts and read in a few places where folks disconnected there proportion valve rod and tied it up so the valve was in the full open postion; figured that was worth a try. I popped off the lower mount point of the rod, tied it up and tried the in-gear/on stands test again. Result: Great and immediate wheel stoppage every time I pushed down on the pedal.
I'm going to drive it for a few days to make sure I don't get wheel lockup but I have a feeling I'll be getting rid of the proportion valve via the TSB part. There are also posts about leaving the rod in and making it adjustable. My truck is probably like most in that it's already meeting the operating at 75% GVW recommendation/suggestion of the TSB without having a load or having the trailer hooked up.
Conclusion/Recommendation: Those of you who have rear wheel drum brakes I would suggest you try the break test I did (on the jack stand test). I was already doing the jack up and adjust star thing but with little to no fluid pressure getting back to the cylinders it was pretty much not helping anything. It was watching the wheels still turn with the brake depressed that opened my eyes.
The bad news is I probably didn't need new cylinders and my old shoes where hardly worn (but cracking in places). The good news is clyinders are real cheap so I'm not really out much there and the even better news is the rear brakes are actually doing something at the present time.
Hope this post helps someone else out.
Rich
Last edited:
