Soft Brakes???

When it starts warming up, and I've run my car for a while my brakes start getting soft - they go almost to the floor before they start getting harder. Any ideas what this could be?

check your brake booster. Mine did the same shit and kept getting worse. Turned out to be my booster. Id look at it asap too because your always going to need to stop.

it could also be a problem with air in the brake lines, they may just need to be bled. i had a guy in my class that had the same problem, but don't just count on the first thing someone tells you. this problem could be alot of different things.

Yea, i agree. Thats another possibility. But to check your booster, heres what you do... Dont start the car, just sit in it and pump the pedal a few times so it gets nice and stiff (dont laugh) when it does get stiff (if it never does its a bad check valve), hold it down and if it gradually sinks or goes to the floor, you may have either a leaky hose, leaky cylinder, or a bad master cylinder. Now, with your foot on the brake, start the car and it should sink a bit. This is to test your brake booster. If it doesnt sink, the booster or check valve is bad.

chronic brake-booster syndrome - CBS!

Well, it's not a leaky hose cause I've had the same brake fluid amount for the last few months -

Master Cylinder??? Before I got the car that happened to my parents after a while and it was the master cylinder, i believe.

I'm going to bleed my brakes tomorrow, but whats really weird about this is that the brakes can be really soft one stop light, and the next they are normal. They keep going back and forth, fine, then soft, then fine - really weird - I'm hoping it's just a bubble or air in the lines. I don't feel like messing with the master cylinder. BTW - how easy is it to remove and/or replace the master cylinder or parts to it???? I've never messed with it.

Its not too hard at all. Pretty much just take the old one off, put the new one in, bleed the lines, and your set. It really does sound like a master cylinder or booster problem to me though. Kinda sounds like the primary or secondary seals are getting too soft which means replacement of the MC.

i have the same problem ever since this guy took out my master cylinder to get out my alt. but anyways...when i stop and SLAM the brakes they work fine but say if i stop and gradually come to a stop i have to usually pump it at least once sometimes more...im pretty sure i need my lines bled but i dunno...the fulid has been the same for a long time too so its not leakin

Ya, mine is like that too - if I try and stop really quick and slam on the brakes they are fine, but a gradual stop they slowly go to the floor. We'll see what the bleeding does.

sounds like the master cylinder to me... same thing happened to my wifes accord.
do yourself a favor and buy a rebuilt one and throw it in. i went to Kragen and bought one and it was the same one as the factory one that i pulled out and it was really cheap.... haven't had any problems since.

Also, if it turns out to be the MC, dont forget to bench bleed the MC. makes bleeding a lot easier.

Also, if it turns out to be the MC, dont forget to bench bleed the MC. makes bleeding a lot easier.


was just about to mention that, me and my buddy replaced mine in 2 hours mainly cuz the lines to the mc were a bitch to loosen, and cuz the bench bleeding took a lil while to do, its not a hard job to do tho

I bled my bakes some today - and I noticed something - what color is brake fluid supposed to be - the stuff that came out was like this greenish color (darker too) - the new stuff I bought to put in is clear? Is that normal?

hey lemme know if u just had bleed the lines or if ur gonna hafta replace the MC

I bled my bakes some today - and I noticed something - what color is brake fluid supposed to be - the stuff that came out was like this greenish color (darker too) - the new stuff I bought to put in is clear? Is that normal?
Lol you used the antifreeze! j/k. I hope u get this problem fixed.

Lol you used the antifreeze! j/k. I hope u get this problem fixed.
Damn - that explains it - last time I take my car to Les Schwab to have the brake system flushed. Update - I bled the brakes some today to see if there were any brake bubbles - didn't find any, but from driving through out the day, I noticed that it takes a lot longer (driving time) before the brakes get soft - I'm wondering if maybe it's just really old brake fluid and it needs to have new stuff put in. We'll see.

Damn - that explains it - last time I take my car to Les Schwab to have the brake system flushed. Update - I bled the brakes some today to see if there were any brake bubbles - didn't find any, but from driving through out the day, I noticed that it takes a lot longer (driving time) before the brakes get soft - I'm wondering if maybe it's just really old brake fluid and it needs to have new stuff put in. We'll see.


that could be a possibility, if u havent changed ur brake fluid for a long time it could be breaking down on u