Brake booster?

HOrunner · May 24, 2007

I have an 85 4runner, i just swapped in a dual diaphram brake booster from an early 90's truck, brakes are awsome but when i push on the brakes and hold down the pedal goes all the way to the floor. Is this normal as it seems it should not be. Anybody know whats up with this?

Not Jobless · May 24, 2007

Did you remove any of the brake lines from the master in the process?

Sounds like you have no pressure building up in the master which means you have a serious leak or a lot of air in the lines.

HOrunner · May 24, 2007

no, but after i put in the booster, my passenger caliper blew a piston seal. I put on a new caliper, but only bled the front passenger hoping air didn't get to far into the system. do i need to bleed all four corners?

cisco · May 24, 2007

Its easy enough so worth a try.

Toyotanut · May 25, 2007

does it go to the floor when running or with the engine off? and you may as well bleed the whole system just for grins.

HOrunner · May 28, 2007

Bleeded the whole system and still goes to the floor, but only when the truck is running?

68jeepsterkid · May 29, 2007

there is a check valve right where the manifold vacuum line hooks in, its plastic.if you run the truck and pull it out of the booster it should have a large suction sound.(after you turn the truck off)if not you may have a bad check valve or your vacuum line may have a pin hole in it.is the vacuum booster new?