I have very little pedal pressure, basically. For about the first 1/5th of the pedal travel, it dosen't do anything. Then it builds a bit of pressure, but not much. The brakes will sometimes hit the floor, but only when I really step on em, and I can't lock up my 31s from any speed. The brakes don't build pressure if you pump them. Sometimes there is some inital pressure when I step on the brakes, but rarely. I've tried bleeding all 4 corners till every corner is shooting out nothing but clear fluid. Whats odd is then when I fill up the container, it seems like some drains back in to the system. I've replaced the master cylinder with a new reman. I'm out of ideas. The truck rolled over 120k miles on the drive home from putting the new master cylinder on at a friends house today.

 

http://www.motiveproducts.com/02bleeders.html

You want the 0251 Model, It's like the 8th one down. Either try that or take it in to get it power bled.

Sounds like you still got some air in it somewhere.

 

If that dosen't fix the problem?

 

Stuff I looked at on my vehicles everytime a tire comes off. So far I have replaced one caliper, the front pads, rear shoes, rear wheel cylinders. Still got a master cylinder I am keeping a close eye on and a questionable booster. Holding hard pressure on the pedal will give an eratic idle.

Does the pedal have a slight sinking feeling as you press on it?

Is there a slight wetness on the front of the power booster under the master cylinder? (This should have already been fixed if you just replaced your master cylinder.)

On your front pads. Is the in-board pad wearing the same as the outboard pad? Is the right wearing the same as the left?

Pull the rear tires and drums. Slightly peel back one of the boots. Is there any wetness?

After 120K miles, Have you ever replaced the hardware/Spring kits on the brakes?

How well does your parking brake work? Does it completely release?

Make sure you use your parking brake as well. If need be, crawl under the back of the vehicle and start tugging on your cables on each side. This will help to adjust the rear brakes. Just a quick and easy way to do it without digging out a bunch of tools and fighting the adjusting hole. (Tip of the day)

The proportioning valve (the one in the front) and the distribution(?) valve (the one over the rear axle) could have an effect on manually bleeding brakes which is why I recommend a power bleeder.

Brake fluid also absorbs moisture. As a annual or semi annual service, the vehicle should be power bled to change your brake fluid. Not doing that will cause your fluid to create the rust and other products that will take out wheel cylinders, calipers and master cylinders.

 

Yeah, it sounds like you've got air in the lines. Motive Power Bleeder may be your answer. You mentioned that you've replaced the m/c and then the problems started. I'm assuming that you didn't have to pump your brakes prior to the installation.

Troy

 

Ahh yes, when I quickly pump the brake at idle, it studders and almost dies. Is that a sign of a bad booster?

The pedal does sink (bleed off pressure) a bit if you stamp on it.

I don't know as we spilled some fluid changing the MC, I will check in a couple of days.

Didn't think to check, will tonight or tomorrow.

Will check.

I've had it since 114k, and I haven't in the last 6k.

Yes, it does. It isn't super strong, but it works some. Actually it works very little, but it does in fact work.

The fluid that came out of the rear lines was horrendous. It looked like chocolate milk. I went through probably 2.5 bottles of fluid between all 4 wheels.

 

Oh no, the problem has been the same before and after the MC.

 

Anyone?