Having a little trouble with Rear Drums I feel.

Quick backstory, I have an 06' SR5 DC 2WD with 147k on the clock. Today I swapped out front pads, rotors and hardware, went to clean the rear drums and to my dismay, found that the forward shoe on both sides was just reaching bare metal. Rebuilt the drums, adjusted to tolerances, and flushed the system.

Now my pedal is super soft in forward gear, but going in reverse I have a nice tight pedal, so it leads me to believe that the problem lies within something I had missed In the rear.

Oooooooor, I'm just totally missing something.

S.O.S!

 

There's lots of threads on the rear brakes of these trucks. Take a look around and do some searching on the forum. I don't have any pointers other than to make sure and bleed from your LSPV (load sensing proportioning valve) above the axle.

 

Totally missed that. I'll be checking that first thing back at the shop. Thank you!

 

I agree with this. Also, make sure to adjust the parking brake by taking the slack out of the cables and make sure the cables are moving freely.

 

one problem many make when bleeding via the brake pedal pump method is that they squarsh the pedal all the way to the floor instead of putting a block of wood under the pedal to keep it only pushed 2 inches.

squarshing blows yer master cylinder and booster sometimes. just sayin’..

 

https://www.tundras.com/threads/drum-brake-star-adjuster-lever-revisited.94151/

Look in here for pics of proper installation. And make sure you did a proper fluid flush.

 

Probably need about a thousand reps of parking brake engagement.

 

Keep in mind, the parking brake only automatically and properly adjusts your rear brakes....if its working. There have been many many posts here about bad rear brakes and the root cause is usually a loose parking brake cable, which prevents the auto adjusters from working, which prevents proper regular rear brake operation.

 

Two words...Bell Cranks

 

can you link that thread you started on rear breaks?. i remember reading it a few weeks ago right after surgery and it was super informative.. cant find it now

 

I'll try later when I have a little time. It was posted over a year ago and I think most of it was actually in a reply to someone else's thread. I kinda hoped someone would make a sticky out of it as it seems like a problem that pops up fairly often. Its actually pretty easy to fix as long as you understand how the rear brakes work.

The short story is really just that you have to go through your parking brake system and adjust, or replace parts until ALL the slack is out of it. The adjuster only works in the last little bit of the parking brake travel, so if it has any slack, it will never move far enough to adjust the drums properly, and the drums are a lot harder to adjust manually than people think. I only know this, because I did it wrong twice before I figured it out. I got something like six more clicks from my adjusters using the parking brake, than what I 'thought' was correct doing it manually.

The other problem, as hinted at, is that your bell cranks, those funny little levers on the back side of your brake backing plate, can get rusted and seize in place, which of course also prevents the parking brake system from working properly.

 

it should be a sticky becuase it had everything in it iirc. it covered all the bases with pix and fsm diagrams.

 

Everything is functioning well, still have to tweak the adjustment a little, but I found that I hadn't routed the parking brake cable correctly. (That little guide at the bottom) Now I'm getting more bite on my left than my right and that's entirely me adjusting them 10 minutes before shift start and calling it good. haven't gone back to play with it any more.

 

As I was adjusting made sure to check the Bell Cranks as the truck was in NY for almost 4 years whole its previous owner was in and out of deployment. But luckily everything was moving freely and easily, I'm sure the screws have an entirely different story to tell, but everything, luckily, is still in spec so I didn't mess with it anymore than I had to.

 

Be sure the parking brake bracket on the axle is pivoting. It's frequently overlooked, but critically important.

 

My bell cranks were rusted and frozen up in their rubber boots. When I replaced them with new parts, I left off the rubber boots. It seemed like the boots trapped moisture more than preventing moisture. Instead, I covered all of the exterior parts in grease. So far so good.

 

I think the boot may be shielding the hole in the plate the crank passes through, so you don't fill your drums with water/road grime. Covering the crank is just a "happy accident" that traps salt and moisture on the crank. They didnt boot the equalizer at the axle or the turnbuckle at the frame, and if those get crusty you are just as fooked. If someone lives where moisture, and or salt are going to collect it would be wise to coat the crank with a corrosion inhibitor of choice due to the boot. But don't ignore the equalizer bushings and the turnbuckle.

 

geting into some nuance. those connectors where the cable meets the crank those pivots connectors seize up and dont articulate. iow the cable will pull the cranks but the pivots tabs wont pivot so the full measure isnt accomplished. there is another 1/4-half inch of play left on the table when those are wrking proper. disassemble cable and see those tabs.