hey everyone i have a ke30 corolla and i think my brake booster is knackered. i still have brakes ( most of the time ) but every so often my pedal just goes to the floor. just wondering what brake booster ( off what model car ) people are running because you can't get thenm anymore ?

Its not you brake booster it the pedal goes to the floor ,its your master cylinder .

 

To check you booster pump pedal with engine off till its hard ,hold down on the pedal and start the engine should drop down

 

slightly ,not to the floor!!

If its pre 1978 ish, you can get a new one off ebay. If it's the dual cylinder rectangle version (late model ke30), you can buy a seals kit to refurbish the one you have.

thanks for the help guys ill replace it and see how i go

I would start With bleeding brake system. Look for leaks as you go

As others have said, it's not the booster, the booster only reduces pedal effort, a dodgy one will give you a stiff pedal, it won't let the pedal drop to the floor or give you no brakes, you'll just have to push harder.

 

 

Is the fluid level going down?

If it is you should be able to see a leak.

If it's not the master is bypassing internally, probably able to kit it if the bore is ok.

 

Jon

No leaks anywhere and i'm not losing fluid.

I completely lost brakes tonight for a good 5 minutes, got home turned car off went and checked it about 5 minutes later and i had brakes again.

I'll get a new master cylinder and new fluid, change them out and see how i go.

 

Thanks for the help guys

Edited August 3, 201610 yr by Seeno

If I was you, i would take the master cylinder out of the car and bench bleed it. Plenty of tutorials on the net to explain how to do it. Once you get air in the master cylinder, it is very hard to get it out whilst it's fitted to the car and it can cause the sort of problems you describe. You can bleed at the wheels as much as you like and the problem will persist.

 

If you do fit a new master cylinder, make sure you bench bleed it before you install it.

 

Also, on the side of the master cylinder there is a bolt. This is the piston stop bolt, and it keeps the internal pistons correctly located. If you mistakenly believe this to be a bleed valve (it isn't) and back it off to try and bleed the master cylinder, the pistons will sit incorrectly and your brakes won't work properly either.