I have a 1990 Toyota Celica GT with a 2.2 engine. The brakes went out on it
but it does not seem to be the pads or roters as there was no grinding,
I checked the brake fluid level and it was very low (I had put fluid in 4 days ago) leading me to believe that there may have been a line go out (I do not drive this car, my friend does, so I am not sure if it lost pressure over time or if it happened all at once)
To check this I got in the car and pumped the brakes three times. They built up pressure leading me to believe that the lines were okay as in my experience a line went out no pressure could be built.
I then immiediatly thought of the master cylinder but found it to be dry both on the firewall in the engine compartment and the firewall within the car.
I added brake fluid and I did not see any major leakage anywhere under the car.
At this point I am thinking that it may be a wheel seal leaking brake fluid. Does this sound like a possibility and if so how can I check it without actually removing on wheel at a time. Also if it is a wheel seal how much can I expect to pay for this item.
masters can leak internally... really, the only way to know for sure what's up is to remove the wheels. start w/ the rears b/c blown wheel cylinders are pretty common (replace them in pairs) and will cause low pedal. but DO check it all out. brakes aren't something to be taken lightly, especially a problem of this nature. good luck! :thumbs:
(To check this I got in the car and pumped the brakes three times. They
built up pressure leading me to believe that the lines were okay as in my
experience a line went out no pressure could be built.)
This points at least to there being air in the system as a good braking system should not pump up at all! Unbolt the master cylinder from the servo and check to see that the seals haven't gone on it and are leaking internally into the servo. If that is OK clamp each brake hose leading to each road wheel in turn and see what the difference in the feel of the pedal is. When you get a good pedal without having to pump, this points to the offending quarter of the car.
I hope that this is of some help.
Not sure where you got your info but it's very incorrect. With the engine
off, a good pedal will build pressure and be too firm to push down after
3-4 pumps. If you have a pedal that is this firm on the first pump, there
is a big problem.
Air in the system will usually cause a spongy pedal when braking due to the fact that air compresses much more than brake fluid(which doesn't really compress at all). This can usually be cured by a brake bleed.
Now back to the original complaint, if the master is low it's not an internal leak because that just leaks back into the resevoir. If you say you couldn't detect an external leak on the master, then it may very well be a wheel cylinder leak. It could be a very small leak that seeps over time and that's why your pedal will get firm when you pump it up. Over time it may leak enough to be low.
Hope that points you in the right direction and as always, the opnion from an experienced tech will be your best bet if you know one that won't charge to look at it.
go back to school, brake fluid does not compress, those are the physics behind a hydraulic system, and why would there be a serious problem if the pedal is high and hard on the first pump with the key off?
Lol did you not even read what I said? I clearly stated air makes the pedal
spongy because it compresses unlike brake fluid. You even quoted me saying
that. I used the phrase "doesn't really compress at all." I thought that
would give the general idea but now I see I have to explain myself. Fluid
does compress, but your hydaulic brake system is not capable of compressing
it. I'm kinda picky about making sure I state things technically correct so
I said it like that. I can see where I may have mislead you.
As far as hard pedal on one pump, I exaggerated when I said big problem, but that's not normal.
that would mean that either the linkage is binding, or the booster is not holding a vacuum for some reason...
My brakes are the same with or without the engine running. Does this mean I have a problem? No, it just means I have an un-assisted braking system. Do not make assumptions, especially when dealing with the only thing that can and should stop a car (without hitting something). As for the pedal stopping moving after several pumps...I don't think so, because if that is the case then the slave cylenders (which, tenchnically, the wheel cylenders and calipers are) are all siezed and not the problem. This is a forum where people come to get advice about repairing thier cars, not where people come to espouse whether or not fluid compresses and at what pressure, temperature, etc. :evil:
Sorry, bad headache today. :banghead: :laughing:
Or it could be leaking past the piston seal into the booster. :2cents: