My brake pedal started going to the floor one afternoon so I changed the brakes thinking they might just be getting low. They still had a good amount on them, but I put the new ones on anyway.

They were good for a little bit, maybe a few weeks and then suddenly started going to the floor again. If I pump the brakes it doesn't make any difference, the pedal still goes nearly all the way down before stopping.

Sometimes If I press down hard and let up a little slowly and then press back I get some resistance but it doesn't last after that.

Could this be the brake booster? Should I start by bleeding them and see if it still goes to the floor?

Thanks!

 

That sounds like the master cylinder. But, I'd check the system for leaks (especially the rear wheel cylinders) and make sure there are none.

If there are no leaks, I'd try the master cylinder first, they are not that expensive. Then flush the entire system with new brake fluid. Most people don't know, but you are supposed to change the brake fluid about every 2 years.

 

Yeah, little bit more work. Dont you need to bleed all 4 when you replace the master cylinder?
Breaks are stick and all the way up when the car is off as well (after one press in to the floor) so I guess the brake booster is good right?

I know the the fluid in the system now is pretty old as well

 

Yes, if you replace the master, you'll have to bleed all 4 - just make sure you bleed until the fluid that comes out is new at each corner.

The brake booster rarely fails, and if it does, it is only an assistance device so the brakes will still operate without it - just need more pressure on the pedal. It has nothing to do with the pedal going to the floor.

 

if you get a Master cylinder buy new. I bought a rebuilt and it was as bad or worse than the one I was replacing.