Brake booster question

[Ranger_danger765]

Hello,

I am new to this forum and was hoping I could get some help with a problem I've been having with the brakes on my '99 Ranger 4x4 3.0L.

My question is basically what are the signs of a worn out brake booster? Right now my brakes feel fine under normal braking, but when I try to stop quickly, the pedal will go down a ways and then get stiff. In order to stop any quicker, or to get my abs to kick in, I have to really stomp on the pedal.

It seems to me, that the brake booster is working up to a point, but then runs out of vacuum causing a weak booster.

Any other ideas of what may cause this?

Thanks in advance,
-Nathan

 

[rileyrs]

sounds like your brakes might just need to be bled.

 

[Ranger_danger765]

Maybe...

Here's a little background. My truck has been like this for about 2 years, progressively getting worse. Last fall I did some work on my brakes in hopes that I would find the problem as well as take care of some other issues. I ended up replacing pads, shoes, rotors, drums, wheel cylinders, and I completely flushed the brake fluid. Now, me and my friend did a decent job of bleeding the brakes. We bled each corner (starting in the back) multiple times, until there was no more air. Even after doing all that, I still had the same issue with the brake pedal.

Could I be bleeding them wrong? I thought it seemed pretty basic. Push down on the pedal, open bleed screw, close bleed screw, lift up on pedal, repeat.

Also, I just noticed I posted this in the wrong section, so if someone could move it, that would be great.

Thanks for the help,
-Nathan

 

[rileyrs]

it helps to pump the brake up about 4 times, then open bleeder, then have the person in the cab push to the floor, and then close the bleeder before the flow of fluid stops.
repeat a few times at each corner, then move on.

 

[mr2fix2it]

i have seen this on econolines before if im correct this has just rear abs than the rabs valve could be causing this to see try to isolate the rear or the truck and see how high you can get the pedal isolate the rear from the front by blocking it off at the master cylinder to see if you get a higher pedal note dont do a lot of driving like this you only have front brakes its only a test.if its better next step is the valve

 

[Ranger_danger765]

Thanks for the tips.

I should also mention I have been having a problem with the rear tires locking up occasionally under normal braking. Maybe related?

Oh, and BTW I do have 4-wheel abs.

 

[rileyrs]

is your fluid overfilled?

 

[Ranger_danger765]

Fluid level is fine

 

[Ranger_danger765]

Ok, I think I finally figured out what was going on. I believe the low pedal was caused by my drums being out of adjustment (adjusters are not working), then when I changed out my wheel cylinders I must have gotten a little fluid on the shoes which caused them to be sticky.

Since discovering this, I have cleaned up the shoes and adjusted the adjuster. The truck stops much better now, and the pedal feels more like it should. The rear still feels a bit grabby, I'm hoping the shoes will wear in and the remaining brake fluid residue will burn out, but I will most likely have to replace them.