Over the weekend, myself and BigBlue upgraded the wheel cylinders on my rear drum brakes to the larger Chevy wheel cylinders. The swap itself was fairly easy, although getting all the springs apart and back together was a nightmare. Anyway, long story short, I'm now experiencing problems with the brakes.

1) the brake pedal has a lot of "dead travel" in it when you first push it; it does nothing for a ways, then it starts to brake

2) when you release the brake pedal, it SLOWLY eases back into the neutral position (it doesn't pop right back)

3) the parking break has to go almost all the way to the floor before it stops, whereas before it stopped much further back

4) after driving for a few minutes, the ABS light and the BRAKE light come on and stay on until the truck is turned off and restarted

The biggest problem for me is the fact that the brakes don't begin to work as soon as you push the pedal. I'm thinking that maybe there is some air in the system, but I'm also thinking that the rear brakes need to be completely re-adjusted. Can someone detail the procedure for adjusting the rear brakes? I found a post about how to bleed out all the air on another thread. Thanks so much.

 

1. You have air in your lines. You need to bleed them properly.
2. See answer #1, and the second 1/2 of answer #3.
3. The clyinders have nothing to do withg the E. brake. You might not have put them back togeather correctly, or the springs might be in the wrong position or slipped off.
4. Adjusting them is faily straight forward. Plenty of threads about adjusting the rear drums.

If BB helped see second 1/2 of answer #3.

I just could not resist BB! It was a slow pitch right across the plate and a little low.

 

Is there an adjustment in the back for the emergency brake? If so, I think we might have adjusted it without realizing it and it needs to be re-adjusted. If there's no way to adjust the emergency brake at the rear wheels, then...I don't know what's going on.

 

If the star wheel is not adjusted correctly the E brake is not either. They are one in the same. Just take a deep breath, we'll fix you up. You have the hard stuff done. The rest is easy. Start with proper bleeding of the entire system. Start at the right rear, left rear, right front, left front. Be patient and DO NOT reuse brake fluid.

Get a diagram of the rear brake drum (or use BB truck as a guild) and make sure everything is where it is suppose to be. Adjust the rear drums per instructions.

 

My truck has disc brakes like a normal truck should. We bled the brakes but only the back two. Fluid came squirting out of both drums. Didn't even think about the fronts. I put the star wheel adjuster thingys right back in the middle of the little bracket they rest upon. That's where I found them and that's where I put them back to. The springs, while although a pain to get on, are all back in their correct positions and are very well seated in their original positions. I pulled both drums off and used one as a guide while I put the other one back together. The fact that they at least half way work is impressive to me since this was the first (and hopefully the last) time I've ever done shoes.

Refresh me on bleeding the brakes. You start the truck and have someone in the cab to press the brakes. You have them press the brakes while you crack the bleeder. As soon as the pedal is depressed all the way or fluid comes out you shut the bleeder. If no fluid came out, you repeat until a nice stream comes out, right?

 

I know you said it, but just to confirm...the front breaks have to be bled too, eventhough we only messed with the rears?
Where can I get this diagram and what is BB truck? It'd be good to have these instructions on how to do the adjustment.

Edited to add: what level of disassembly has to be done to adjust the drum brakes?

 

Regarding bleeding procedure, Wannadiesel posted this on another thread:

 

BB truck is my truck. BB, BigBlue. Get it? Good aggie.

 

Ah! Well, BigBlue's truck is in a different city than I'm in now, so I can't use that. Also, his truck has rear disc brakes (thank God!). I'm pretty sure everything is put back right though, so I think that's fine. I don't have any instructions on the adjustment procedure though. Was hoping y'all could help. Thanks so much for everything guys...y'all are amazing, really.

 

https://www.dieseltruckresource.com/...ing+Rear+Shoes

 

What kind of brake fluid should I use? If I'm going to go to the trouble of doing the bleed, I might as well do it right and use the best fluid available. I need to get this **** working ASAP. Got an out of town trip this weekend. Thanks again guys.

 

even having only done the rears, you should always bleed all four when done. this assures you have no air left in the lines.

here is a good generic description of How-To Bleed Brake Lines... remember NEVER let the master Cylinder go dry or empty while doing this.. if it does, start over from the begining...

Bleeding Process:

Begin at the corner furthest from the driver and proceed in order toward the driver. (Right rear, left rear, right front, left front.)

Locate the bleeder screw at the rear of the caliper body (or drum brake wheel cylinder.) Remove the rubber cap from the bleeder screw – and don’t lose it!


Place the box-end wrench over the bleeder screw (10mm for discs, 8mm for drums.) An offset wrench works best – since it allows the most room for movement. (If you do not have an offset wrench, avoid pushing the wrench head to the bottom of the bleeder screw – since the wrench may interfere with other parts during movement. Allow a standard wrench to sit near the top of the bleeder screw contact point.)


Place one end of the plastic hose over the nipple of the bleeder screw.


Place the other end of the hose into the disposable bottle.


Place the bottle for waste fluid on top of the caliper body or drum unit. Hold the bottle with one hand and grasp the wrench with the other hand.


Instruct the assistant to "apply." The assistant should pump the brake pedal three times, hold the pedal down firmly, and respond with "applied." Instruct the assistant not to release the brakes until told to do so.


Loosen the bleeder screw with a brief ¼ turn to release fluid into the waste line. The screw only needs to be open for one second or less. (The brake pedal will "fall" to the floor as the bleeder screw is opened. Instruct the assistant in advance not to release the brakes until instructed to do so.)


Close the bleeder screw by tightening it.


Instruct the assistant to "release" the brakes. Note: do NOT release the brake pedal while the bleeder screw is open, as this will suck air back into the system!


The assistant should respond with "released."


Inspect the fluid within the waste line for air bubbles.


Continue the bleeding process (steps 11 through 16) until air bubbles are no longer present. Be sure to check the brake fluid level in the reservoir after bleeding each wheel! Add fluid as necessary to keep the level above the seam line. (Typically we repeat this process 5-10 times per wheel when doing a ‘standard’ bleed.)


Move systematically toward the driver – right rear, left rear, right front, left front - repeating the bleeding process at each corner. Be sure to keep a watchful eye on the brake fluid reservior! Keep it full!


When all four corners have been bled, spray the bleeder screw (and any other parts that were moistened with spilled or dripped brake fluid) with brake cleaner and wipe dry with a clean rag. (Leaving the area clean and dry will make it easier to spot leaks through visual inspection later!) Try to avoid spraying the brake cleaner DIRECTLY on any parts made of rubber or plastic, as the cleaner can make these parts brittle after repeated exposure.


Test the brake pedal for a firm feel. (Bleeding the brakes will not necessarily cure a "soft" or "mushy" pedal – since pad taper and compliance elsewhere within the system can contribute to a soft pedal. But the pedal should not be any worse than it was prior to the bleeding procedure!)


Be sure to inspect the bleeder screws and other fittings for signs of leakage. Correct as necessary.


Properly dispose of the used waste fluid as you would dispose of used motor oil. Important: used brake fluid should NEVER be poured back into the master cylinder reservoir! Dispose of the fluid as you would motor oil.

 

Not true.
There is no need to bleed the fronts unless you run the master completely out of fluid. Even then it's hard to effect the fronts since the master has two halves, front and rear.

It sounds to me like you just need to adjust the brakes, I would start there before bleeding again. Jack up both rears, there are two rubber plugs at the bottom back of the wheel. I always forget whether it's the front or back one but anyways remove one, under it there is a starwheel, turn the star wheel upwards with a screwdriver while spinning the tire. Once you hear the brakes start rubbing stop, you are done, do the other side.

 

What kind of fluid should I use? Also, I don't have the rubber caps on the rear wheel cylinder bleed valves anymore--we threw them away cause they were messed up anyway. Is this going to be a problem?

 

Good old o'reilly brake fluid. You could buy really expensive stuff but then you'd have to flush the whole system out to take advantage of it. Just buy the same stuff you bought the other day and you'll be fine. The caps are only there to keep dirt out. Don't worry about those either. Try adjusting the brakes first and see how that goes before you decide to bleed the system.