Mystery Brake Problem After Engine Rebuild

[manage13]

Mystery brake problem- R32 GTR

Hi everyone, I have had some issues with my brakes that not even my family mechanic can solve (he knows his V8’s however his knowledge with jap turbo engine is scarce).

The problem I’m having is that my brakes are not feeling the same as they once were before my engine build. Basically the brakes feel as if one was to drive a car and switch off the ignition and try and brake. That same feel I have constantly.

I checked the vacuum at the brake booster (where the one way vale is) and if feels as if there is not enough vacuum. On my boost gauge at idle reads 5 psi on the vacuum side.

Does anyone have the slightest idea as to what my problem is? Any help will be greatly appreciated.

Thanking everyone in advance.

[PHATR32]

so there definetly is vacuum on the hose while the engine is running? have you pulled the hose off from the booster side to see?

[ali-turko]

what dose it mean when u take the hose off the booster and your brake pedel feels like it should coz i got a spongy pendel but when i pull the hose off the booster the pedal feels great

[[WLDCRD]]

just cut a hole in the floor and use a stick to slow you down

[ebola]

what dose it mean when u take the hose off the booster and your brake pedel feels like it should coz i got a spongy pendel but when i pull the hose off the booster the pedal feels great

Sure, it "feels" like it should.

I lost vaccuum on my brake booster in my magna once. The brakes "felt" alot harder - much like I am sure yours do.

The problem (!) is that you still have the same amount of braking for the same amount of pedal throws - its just alot harder to get the pedal down that far.

Also, brakes are brakes. They all work on the same principle (regenerative braking aside - but you don't own a hybrid, right?). Stand brake advice applies.

(I'm not a mechanic, so.... advice from here on is... opinion only. I have lots of opinions.)

bleed first.

Then check all cylinders.

take it to a brakes specialist.

--ebola

[blind_elk]

You have a permanently "heavy" pedal, is that your problem?

Here's a dumb thought - is it possible to put the hose on "arse-about"? Maybe the valve is facing the wrong way. Or the valve is cactus.

[ali-turko]

nar my pedal is slopy but when i take off the hose for the booster the pedal feels great

[CameronBNR32]

I'm thinking its the one valve like blind_elk said, it should have a arrow indicating the correct air flow direction.