Vacuum

[redneckaggie]

did you ever replace the vacum pump?

I have replaced every single component except hard lines on my truck. start the truck up with a vacum gauge hooked to it coming directly from the pump. should have 22 in hg within seconds at idle. kill the truck after you note where the gauge is and walk away for 15-20 min and come back to make sure gauge isnt loosing vacum. if that checks good move down the line to the hose right before the booster and check that to check for leaks in the lines(happened to me). if that checks out good and the pedal is firm when you unhook the vacum from the booster then its the booster.

 

[Cincinnati Guy]

Ill go try that, and no I havnt replaced the vacuum pump. I always thought a bad booster would make the pedal hard?

 

[redneckaggie]

not in my case I had a mushy pedal first, and a new mc fixed that but then i had a hard pedal and i replaced the vacum pump(tested bad) and the prob persisted and i replaced all of the vacum lines. then the pedal got mushy again and i went through 6 mcs(from napa i wouldn't buy any hydraulic part from oreillys) with no luck and then finally I said eff it and replaced the booster and all was well.

 

[Cincinnati Guy]

Replaced the brake booster, the old one was all rusty inside maybe some parts were sticking. Found out the seal on my cap for the master cylinder is torn. Can't find a store that has one! I'm repairing mine until I can go to ford or where ever to get a new one.

 

[redneckaggie]

Oreillys had the whole plastic reservoir for mine. took them a little time to dig it out though. I wouldnt have bought it from them but they were the only ones that had it at the time. In my experiance unless I have no other option I wouldnt buy hydraulic parts from oreillys or electrical from autozone. I went through about 6 master and slave cylinders from oreillys that would work fine and then start goin after a while. I also helped a buddy with his truck and we chased electrical gremlins forever and couldn't find a thing wrong causin auto zone starters and alternators to blow evvery few months, swapped to napa and those napa parts are still in it about 5-6 years later. IMO a lifetime warranty aint worth swapping parts every few months.

 

[Cincinnati Guy]

Got it all bled out and nothing has changed! The only thing brake wise that hasn't been changed is the abs unit, brake lines and vacuum pump!

 

[HankHill]

guess its the vacuum pump then? are you sure maybe theres no holes in your brake lines?

how much did that booster cost you

I think napa has vacuum pumps for $125, expensive for me however I don't think I've seen a lower price elsewhere

hey maybe theres a pinhole in one of your vaccum lines? not sure what would happen if there was but maybe one of your vaccum lines are torn

Edit: I just reread your post, isnt there a vave on the abs unit under our trucks where you can bleed air out of it? I think I recall something about this

 

[Cincinnati Guy]

Im going to hook my vacuum gauge and see if it holds vacuum.

Yes there is a bleeder on the ABS unit.

 

[Cincinnati Guy]

It has to be the ABS unit. Bled the brakes a lot this morning. With the truck off I can pump up the pedal and have a nice firm pedal but as soon I start the truck is sinks to the floor.

What is all involved in by passing the RABS?

 

[Cincinnati Guy]

I think I figured it out!! Took the RABS off and opened it up and wow!!! Bunch of rust and what looks like water. Time to go to the junkyard. The blue piece inside isnt that a piston? Mine dont move.

 

[HankHill]

any pictures?

 

[Cincinnati Guy]

Ill get some.

What vehicles can I get one off of?

 

[icanfixall]

Your better off buying a new part... How will you know the wrecking yard part is any better than what you have... Remember... These are brakes.... Not speakers but do what you can afford. I understand cost issues. Ebay has them offered really cheap. Probably around $45.00 to $65.00 and your going to know things are right. Its not fun to panic hit the brakes only to find out you don't have any... My heart can't take two surprises that close together these days....

 

[Cincinnati Guy]

Right now thats just going to have to be a chance I take. I will keep on the look out for a new one on Ebay and here. I have a few things I need replaced on the truck so I gotta do what I got to do.

here are a few pictures like I said.

Isnt that blue piece the plunger and suppose to move?

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

 

[nitro joe]

i had the same problem and i replaced the booster only to have to adjust the rear brakes, now i have good brakes