Got a brake problem any ideas?

[mercuryfreak200]

Ok so I searched through the threads this one was close to what is wrong. But I just want to know if its my brake master cylinder or booster. So I drive for awhile and the brakes start to get soft then a little softer and then they go to the floor. There was no resolution in the thread that I found being it sounded more like they broke their bleeder valve and couldn't get fluid to the reaer brakes. Heres the thread,


http://www.supramania.com/forums/sh...e-problem...&highlight=loosing+brake+pressure

Anyways I'm not loosing any brake fluid, the master cylinder is full and I don't have any vacuum lines missing or off. I checked under the intake, the ones on the power steering pump, etc.. Any help or ideas would be great or if you think its the brake master cylinder or booster how do I check and make sure thanks again..

 

[Freshmaker]

A booster problem would give a rock hard pedal. You can rule that out.

So what restores the firmness to the pedal?

ps don't drive the car until you figure this out.

 

[mkiiichip]

Sounds like you need a new master cylinder. If your going to get one from a local parts store i would recommend "ASIN" brand. Its oem.

Likely not a booster problem, but might as well check it. Your going to have it half way off anyway.

To check booster, put a vacuum on booster with a handheld pump, and make sure it holds vacuum and does not bleed off.

 

[mercuryfreak200]

Obviously driving the car would be stupid it started today when I went to get a drink. Doesn't help that I'm already pissed off the someone side swipped it last night and took out my mirror and scrped the side of the car all up in places and scratched my hood when the mirror went into low earth orbit.

 

[mercuryfreak200]

What restores firmness to the pedal is just shutting the car off and then turning it back on. I think it because it all looses vacuum and the master cylinder reseals or returns to a somwhat normal state.

---------- Post added at 05:14 PM ---------- Previous post was at 05:12 PM ----------

I've only been driving the car for three days and I figured after sitting for three years not driving somthing would go haywire, thats why I havent took it very far just drove to work and back.

 

[IJ.]

Car off pump the pedal 5>6 times to exhaust the brake booster

Hold firm pressure on the pedal and see if it creeps to the floor over time.

report back here.

"Pedal Height Retention Test"

 

[mercuryfreak200]

Alright I will try this IJ

 

[mercuryfreak200]

Okay so I tried what I was told to do by IJ, and with the car off and I pump the pedal and hold it stays hard as a rock, when the car is on and I pump it and then hold it the pedal will start to creep down to the floor.

 

[IJ.]

Check the Booster where the master cylinder bolts up and see if it's wet at all.

 

[mercuryfreak200]

No its dry I just wiped my fingers around all the fittings and where it bolts to the booster. I haven't lost any fluid either its still full. I checked my abs box fittings too nothing there same for the calipers.

 

[Poodles]

There is a seal between the booster and master, you have to loosen it to check for leaks.

 

[IJ.]

Crack the Master Cylinder nuts loose where it bolts up to the Booster and break the master loose and see if anything comes out.

The pedal height retention test you just performed indicates the seals are sad but not at the point where it's leaking badly yet.

Is this an ABS car?

 

[mercuryfreak200]

Yes it has abs I was thinking about getting rid of them even though they still work amaizingly. I will try taking the mc off real quick.

 

[Poodles]

It sat for 3 years, did you flush the brake fluid?

 

[IJ.]

Don't need to take it off just loosen the nuts and crack the gasket a bit, if it's wet inside you'll see it.
(have some water handy to flush any leaked fluids off the bay paint)

 

[mercuryfreak200]

Yeah its a little wet not bad though. I'm loving having this new garage, so easy to work on things. Anyways so I'm guessing that means I need a new master cylinder and a ride to work lol.

 

[mercuryfreak200]

Am I right? And no I didn't flush the brake fluid its not dark or anything looks new.

 

[IJ.]

Yes a new MC is in order, also grab a few extra bottles of fluid and flush the entire system through as brake fluid attracts water.

 

[mercuryfreak200]

Oky doky will do this coming weekend when I get paid which mc should I buy?

 

[IJ.]

Don't know if you get much of a Choice, personally I went factory but if it ever needs replacing I'll get it sleeved in SS and put a kit through it that way it'll never rust/corrode again.