What the hell would cause this? I had this happen to me yesterday only when it is extremely hot outside, it does not do it in the morning and at night. I just re-bled my brakes yesterday after I noticed it happen and I just got home and it was doing it again. I will have firm pedal pressure when cruising and then coming to a stop, but in stop and go the pedal practically goes to the floor everytime until I get moving again and then its fine. Any help is appreciated

 

Perhaps you are heating the brake lines and boiling the fluid. Is there anything done to your car that would cause this?

 

Unless he's tracking or heavily abusing his car, I doubt he is boiling the fluid. Did you check for any signs of leakage in the MC? Or the hoses?

 

Its time for a new master cylinder. The seals in your master cylinder have worn out. I know this is a common problem with Integras. As a matter of fact, I'm having the exact same problem.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by p nut &raquo;</TD></TR><TR><TD CLASS="quote">Unless he's tracking or heavily abusing his car, I doubt he is boiling the fluid. Did you check for any signs of leakage in the MC? Or the hoses?</TD></TR></TABLE>

An exhaust leak could heat the rear line. Stopped traffic... heat rising... no boundary flow... yadda-yadda... boiled fluid and soft pedal.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dogginator &raquo;</TD></TR><TR><TD CLASS="quote">

An exhaust leak could heat the rear line. Stopped traffic... heat rising... no boundary flow... yadda-yadda... boiled fluid and soft pedal.</TD></TR></TABLE>

I guess it could, but I've never personally had experience with that. And not to nit-pick, but shouldn't you have told him to look for that exhaust leak in your original post? I know you're trying to help, but it would have clarified your post more and helped the guy pin-point the problem faster.

 

I am definately not over working the brakes, it happens no matter what as long as its 90+ deg out, I just got back from a ride and it just abrely doing it but its still 87 deg out now.

My friend also told me possibly the MC, I am definately not leaking fluid too, I did a full ABS removal over the winter and have just now this week started driving the car, it didnt happen at all until yesterday and it has been 95+ deg since Saturday.


Is there an upgraded MC for Integra's or just OEM? I can pretty much rule out an exhaust leak as it would go to the floor all the time not just when its hot out. The car has almost 140k on it and it 12yrs sold so I guess its time for a MC

 

accumulator seal?

 

It's your brake master cylinder. Try it when it's not really hot outside, apply constant pressure on the pedal, it'll sink then too, it just does it faster when it's hot out. More pronounced sinking. Happened to mine too.