brake sinks only in hot weather

[village1]

Just recently, my 1991 Honda Accord has had brake problems. Only when it is hot out and the car has been in the sun, the brake pedal goes down to the floor with no appareet brake pad contact. When it cools down outside, things are fine. I just had the brake fluid changed. If it is a master cylinder or hose, why would it only happen when it is hot outside, even when I only drive it for a few miles.

 

[Michael Pardee]

Just recently, my 1991 Honda Accord has had brake problems. Only when it is hot out and the car has been in the sun, the brake pedal goes down to the floor with no appareet brake pad contact. When it cools down outside, things are fine. I just had the brake fluid changed. If it is a master cylinder or hose, why would it only happen when it is hot outside, even when I only drive it for a few miles.

I can't think of a time when brake pedal sinking was anything besides the master cylinder (assuming there was no big leak somewhere.) I bet if you wrap the master cylinder in cold rags after it starts sinking the sinking will slow or stop. Or just take the short cut and replace the master cylinder. If it's the original, it's definitely lived a long life.

Mike

 

[jim beam]

Just recently, my 1991 Honda Accord has had brake problems. Only when it is hot out and the car has been in the sun, the brake pedal goes down to the floor with no appareet brake pad contact. When it cools down outside, things are fine. I just had the brake fluid changed. If it is a master cylinder or hose, why would it only happen when it is hot outside, even when I only drive it for a few miles.

master cylinder. some elastomers shrink when warm. time to change. you can get seal-only kits from majestic honda or replace the whole cylinder.

 

[village1]

master cylinder. some elastomers shrink when warm. time to change. you can get seal-only kits from majestic honda or replace the whole cylinder.

thanks -- any idea what this will run in $$?

 

[Jim Yanik]

wrote in

thanks -- any idea what this will run in $$?

Most of the local auto parts stores are online,you can check parts availability and pricing easily.

 

[dgk]

thanks -- any idea what this will run in $$?

I was losing brake fluid (91 Accord) and the problem was that the white plastic reservoir that sits on top of the Master Cylinder had a crack at the bottom. You can't get that part separately, it's only sold as part of the MC. So I went to the local junkyard and got a used MC for $40, took the cup off and replaced the cracked one. Works fine.

That, however, left me with an unneeded used MC which is currently sitting in a plastic bag on the floor of my garage. If you want it I'll be happy to drop it in the mail. Ill monitor a junk email account and if you want it just send your address to:

takethebird@(dropthis part out-even junk accounts deserve a break)hotmail.com

 

[John Horner]

Just recently, my 1991 Honda Accord has had brake problems. Only when it is hot out and the car has been in the sun, the brake pedal goes down to the floor with no appareet brake pad contact. When it cools down outside, things are fine. I just had the brake fluid changed. If it is a master cylinder or hose, why would it only happen when it is hot outside, even when I only drive it for a few miles.

Probably a master cylinder. The bore expands as the temperature rises, so it might be right on the edge. In any case, replace it!

John

 

[Sam Nickaby]

wrote:

master cylinder. some elastomers shrink when warm. time to change. you can get seal-only kits from majestic honda or replace the whole cylinder.

I'm looking for this kit. My seals are shot. I've looked for it at Sleandro Honda and Majestic and found none under their listings. Where would it be?

Thanks

 

[jim beam]

I'm looking for this kit. My seals are shot. I've looked for it at Sleandro Honda and Majestic and found none under their listings. Where would it be?

Thanks

depends on the vehicle. they're not offered on all models, only the high volume stuff like 13/16" civics, etc. if majestic don't list it, you can't get it and whole cylinder is your only option.