well.. yesterday after not driving my 89 si for a month i finally got to drive it, then i noticed that when i would step on the brakes for the first few seconds it worked fine, but after that the pedal would travel almost all the way down and barely stop the car, so i have to step all the way down and it seems like it aint going to stop.... last month when i drove it, it was working perfectly fine... what can i check for??? i need help guys... i hear no weird noises or anything like that...
thanks

 

you might need to bleed your brakes there might be air bubbles in the lines. if not check your master cylinder or booster as they might be leaking

 

Bleed the brakes and inspect for any obvious brake fluid leaks. If the problem persists, your brake master has probably thrown in the towel. The leak is most likely internal, so you won't find brake fluid leaking. Brake master replacement would be your next step.

 

yeah sounds like master cylinder, you could find out if its leaking by, removing the master cylinder from the vacuum booster and checking for wetness around the pushrod of the master cylinder. if theres any moisture, its the master cylinder, also if you have lost a lot of fluid, it may be in your vacuum booster. I suggest replacing and installing the master cylinder, and when its installed you can check to see if the vacuum booster is working properly (pump the brakes with the car off, about 20 times, then keep pressure on the brake pedal, start up the car, if you feel the brake pedal depress when the engine is started, then your booster is working, if not then, you must replce that too. If you have any other questions I would more than willing to help. Hope that helped a little

 

I second the master cylinder. The same thing happened to me.

 

thanks for the help everyone.. i will check it out tonite...
thanks again...

 

Today i checked all my lines and nothing seems to be leaking, but im still having the same problem.. now when the car is just standing, i step on the brakes and the pedal goes all the way down to the floor gradually... anyone have any idea of what is going on???? i think it might be the master cylinder...???

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by crxtreme27 &raquo;</TD></TR><TR><TD CLASS="quote">... now when the car is just standing, i step on the brakes and the pedal goes all the way down to the floor gradually... anyone have any idea of what is going on???? i think it might be the master cylinder...???</TD></TR></TABLE>
It's your master cylinder. There's more than one place for it to leak. Sometimes they leak both places at the same time...

If it was leaking thru the piston shaft seal, then you'd see fluid when you took it out from the booster. But then the pedal wouldn't necessarily sink to the floor.

If it leaks past the piston, then the pedal sinks to the floor. But then it never actually leaks OUT. It just leaks back into the reservoir.

If it was air in the lines, it would be soft & sink to the floor immediately. But you said it was OK for the first few seconds, then it sank.

 

Thanks for your explanation... i should be changing it tomorrow...
thanks

 

I had the same exact thing happen, even when i would pump the brakes i would get pressure for a few seconds...then nuthin, i took off the master cylinder from the vacuum booster and there was moisture where the push rod is. there wasnt any moisture around the master.
now the only problem is that is you have lost a lot of fluid, it could be in your vacuum booster, there is tool (kinda looks like a gas siphon) you can put that in your vacuum booster and siphon all the liquid out, also what i have found to work is (now this is a bitch, but its better than buying a new vacuum booster) is take off the vacuum booster, rinse it with water, since brake fluid is water soluble, and make sure it is COMPLETELY dry, then re install. when you do the master cylinder install (you probably already know) dont forget to bench bleed it, and then bleed all the wheels at the bleeder valves starting from the tire furthest from the master cylinder. sorry for the long post.

 

Thanks for the info, i will try this tomorrow.. if it doesnt work i will replace the master....
thanks

 

everyone, thanks for your help... it was the master cyl. i replaced it yesterday after testing everything i could i decided to replace it.. that was my problem.. now it works great...
thanks everyone..