Brakes not working Properly

Sorry if this came off as a butt head.... was not my intention.

 

I might have to try this... i am almost sure i dont have ABS on my truck.

 

This where the ABS module is located.

 

No we can't unfortunately. Our trucks are too old and not compatible.

I didn't take it that way.

 

I do not have this on my truck... so i would say i do nnot have ABS. Thanks for the picture though.

 

It is mentioned often, because many people aren't aware it is there. Also, it is about a foot above the rear axle brake lines, air in that section will travel up and get trapped in the frame section of the lines, bleeding that air is very challenging without a bleeder at the highpoint. When bleeding at the rear cylinders, that air at the frame level will push down slightly but not all the way down to the axle then it can float back up to the frame between each pump and bleed cycle, forever trapped in the high point. Forever mushy brake pedal.

 

Op - do this first and then go from there. Chances are it's multiple things. I can't overstate how much the rears affect braking in our trucks. Until the rear is sorted everything else will feel off.

On my last tundra, the parking brake hadn't been used in so long that it wouldn't even adjust, I had to get under the truck and pull the bell crank until it started to tighten, then the parking brake would adjust it the rest of the way.

Since you did so much work on the rears, I'm guessing they are very loose.

Get the rears working and then fight the mushy bleed.

 

UPDATE!!!! I adjusted the back brakes to the proper specs and all is fixed... Have the brake pedal I have always had. Thank all of you for all the help.

 

Rear brakes out of adjustment, due to failed or out of adjust parking brake, is usually the source of this problem. I don't know what it would take to get a sticky on this subject but wish we had one as this keeps happening and there isn't always someone around to explain the importance of rear shoe adjustment to brake feel.

 

So let me ask you this. I've adjusted my parking brake per instructions here. It works great. It also passes the test found in the FSM(see next post).

Moving on, I've also manually adjusted the rear shoes while both tires are off the ground. I did this so I could spin them, adjust, spin, adjust again. I got them to the point that I can hear them lightly dragging the drum and I believe they were adjuted correctly. They are tight enough I can't slide the drum off at that point. This made my mushy pedal feel better for a little while before it starts to suck again.

This made me think all my rear components might be worn out. Almost like the rear are coming out of adjustment because the springs and self adjusters are fucked. I ordered all new OEM parts that I'm planning to swap out soon to see if it helps. Even if it doesn't I won't be too pissed because it's probably good routine maintenance on a 20 year old truck.

Unfortunately the passenger side self adjuster is discontinued so I may just have to reuse that one with new springs.

 

Found that rear brake troubleshooting guide that @jpink made from info in the service manual.

 

In my experience, its very hard to properly adjust the rear drums.

When I replaced my rear drums brakes, I did what everyone does, adjust them manually until the drums are lightly dragging, and like most people, I had mushy brakes and my parking brake did not seem to work.

That was when I dove into the brakes and fixed my parking brake system, from the pedal, to the drums. Once I did that, I got about half a dozen more clicks by using the auto adjuster PAST the point where I had thought they where correct. The actual 'correct' adjustment, was significantly tighter than I thought it should be doing it manually.

I think that 'lightly dragging' is essentially irrelevant when manually adjusting the brakes, because under actual braking force, the shoes shift and flex in position. Remember, the shoes just 'float' against the backing plate, held only by springs. The whole mess of springs, levers, and cables, is going to change shape under the thousands of pounds of force it experiences under braking. What we can do with our hands and what feels 'tight' to us, is nothing compared to the forces the wheels and brakes actually go through.

Also, new brake shoes will never perfectly match the surface of the drums. The high points will wear away very quickly as only a small percentage of the brake shoe actually contacts the drum until they wear to match. New brakes will need frequent adjustment until this happens.

With the auto adjuster working, its really obvious as you can use the parking brake until no more clicks are heard, drive a couple miles, using your brakes often, and then get a few more clicks right away as in that period of time those high points have worn down, and this will keep happening for a few days until the shoes and drums have settled into each other. I think this is what you are feeling when you say it seems like your brakes are coming out of adjustment.

I really cannot stress enough, how frustrated you will be with your rear brakes, until the auto adjusters are working properly. The margin of error between so tight they overheat, and so loose they don't work, is really small on our trucks and hard to set manually, and once set, then has to be routinely set again as parts wear and flex. It sounds complicated, but that is why there are auto adjusters to do all this for you.

 

I did mine on jackstand with the truck running, since i have lsd. Adjusted until they locked up evenly, then verified in 4lo lasering the drum temps with em dragging. Within 2-3 degrees.

fgv, i dont wanna be that guy, but are the adjusters engaging the right direction?

 

How would I test this?

So if that's not the correct way to adjust the rear shoes what is? Like I said, my parking brake works great. I know that is critical. I'm willing to listen.

You said you fixed from pedal to drum. What did that involve?

 

I’d think they’re supposed to spread when the brake is applied, and the arm will catch the next notch when released. There oughtta be pics.

 

The correct way is to use the parking brake and let the auto adjusters do the work. This is the only way mentioned in the factory service manual. The thing everyone does to adjust the drums until they lightly drag, is not really a 'thing'. Its a work around, that from all the posts here I've seen about rear brakes, doesn't ever actually work.

You mention that the passenger side self adjuster is disconnected. I think this is your problem.

What I had to do on my truck was tighten the parking brake cable, and fix the drivers side bell crank, which was rusted and seized.

 

The reason the parking has to be adjusted properly for the rears to work, is they are actuated at the lower end of the brake shoe. Getting the parking brake adjusted so that it’s working positions the lower part of the shoe in the proper place. That lower end has to be in proper position in order for the uppers to properly engage when pressing the brake pedal for normal braking. The brake cylinder is at the top and presses the top portion of the shoe into the drum. If the lower isn’t properly adjusted, very little shoe will contact the drum.

 

He wrote disconnected, but actually meant discontinued He had to get aftermarket for the pass side.

 

My trouble was a leaky mc, and it would be fine until things started warming up. As the brakes warmed up the brake pedal got stiffer and stiffer. I know its not the same, but i also gravity bled everything until the fluid cleared up. Until the end when id push the brake, set a board on the pedal and bled the pressure.

 

That hasn't worked for me yet. I adjusted the turnbuckle under the cab. That helped the parking brake but didn't help brake pedal SpongeBob.

Thank you. I fixed it. I haven't found an aftermarket one yet. Rock Auto sells self adjuster rebuild kits bit I'm leery of trying more Chinese parts.



And like Sirfive, I too have replaced my master cylinder.

 

Have you physically checked if your adjusters are working?

Manually back them off several 'clicks' and then have someone apply the parking brake while you listen under the truck, you should be able to hear them re-adjust the same number of clicks, or even watch the adjuster move through the manually adjustment port.

The parking brake adjuster is only able to move the adjustment gear by one or two teeth each time its used so you may need to do it multiple times to get all the slack out.

 

Good info here. When I go to replace everything I'll test that. I'm hoping the self adjusters are my issue. Really bummed Toyota is starting to discontinue more parts. I had to get an aftermarket MC too.

 

NAPA has aftermarket kits too, and they are different from the RA ones. I used RA on one side and Napa on the other, due to (un)availability, on my recent rear brake job. If I were you, I would get one of each and try them both out. Probably both made in China though.

 

I set mine with vacuum on the system. And dual spreader springs on each caliper. New and spread on top, old and stretched on bottom.