Brake booster?

[HOrunner]

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]

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]

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]

Its easy enough so worth a try.

 

[Toyotanut]

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]

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

 

[68jeepsterkid]

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?