[Cossie]

Hey guys, i've been living with this prob for 6 months now, and it's started to shit me. When i'm giving the car a flogging (through the hills, or round the Great Ocean Road-coast) and have to suddenly stomp on the brakes, there's a short period when it feels like there's no power assistance.
Seems to only happen when the engine is at high revs and then i simulatneously clutch it and hit the brakes. Does anyone please have any ideas. when i pull my foot off the brake and re-apply, the power assistance is there.
Cossie

 

[ZZT231]

Hey Cossie,

Check you brake booster... You might have a vaccum leak or the diaphram might be going... When idling pump the brake a few times, if the RPM doesn't drop you have a problem with the booster cylinder (I think or could be the other way, can't remember happened to me in the celica a few years ago). Good luck.

Cheers.;

 

[Square]

How old is your brake fluid?

What type of fluid is it?

If you are driving hard with moderate braking here and there you may be in a situation where you are heating up the brake fluid and it is boiling near the calipers. When you get on the brakes hard the air in the lines compresses and you feel like you have less/no braking power. When you pump the pedal, you increase the overall pressure enough that the air dissolves back into the fluid and you have "normal" brakes again. Flushing your fluid and using hi-temp fluid will help if this is your problem.

 

[Cossie]

brake prob solved

Thanks for the replies guys, found out what it is by accident the other day, hopped out my car to fiddle with the battery terminals while the car was running, and as soon as i switched it off, i heard the hissing noise of air escaping from the booster. Lucky ive got a spare, now just got to find the time.
Thanks again
Cossie