brrakes loose pressure when xar is started

[Lunzee]

Hey Guy Ima kinda lost here, I replaced my pads and rotors last night, everything went smoothly, but we started to rebleed the brakes after the install and we have a problem, there is almost no pedal pressure, it still builds pressure if you pump it up but when I start the car all of the pressure goes away, we bled them the old school way by pumping the pedal and we have also bled it with a vaccine bleeder, and we also did it in the correct order, back right,back left,front right,front left. But it just wont work. Any ideas?

[NolimitZ32]

Your order is backwards, you bleed away from the booster, that may be the problem. Never used a vacuum bleeder so I couldn't tell ya anything about that but your problem is either
A) you let air in the system
or
B) your Booster is leaking.

[AZhitman]

To my knowledge, the bleed order is correct. The only car I've ever done any differently was my C5.

It *does* sound like he insufficiently bled the system.

There's no reason to use a vac bleeder on a Z32.

[Lunzee]

There was most definetly air is the system, when the brakes were off and the lines were off if the calipers the brake pedal was compressed multiple times along with the emergency brake. Any tips on how to get rid of all the air? Or if there could be any other problems? There was what appeared to be a leak comeing from where the brake resivour meets the fire wall but it seemed air was coming out, but it has been sealed

[NolimitZ32]

Odd, Ive always been taught to bleed away from the booster, shortest line first.

[AZhitman]

From the Intarwebs:

Bleeding is done one wheel at a time. The "old timers" will tell you to start with the wheel furthest from the master cylinder and work your way closer. Typically, this would mean RR, LR, RF, then LF. However, it doesn't really matter if you start with the front or rear wheels, since they are on separate circuits on modern cars with ABS and/or dynamic stability control systems.

<-- Old timer.

Anyhow, here's a good article for Lunzee: http://www.popularmechanics.com/cars/ho ... ce/4213448

Also, back up - What is this about a "leak" near the firewall? How was it "sealed"? How do you know there was a leak? How do you know it was leaking air?

p.s. The emergency brake has absolutely nothing to do with the braking system. None.

[nissanfreak12]

p.s. The emergency brake has absolutely nothing to do with the braking system. None.

Well it does have SOMETHING to do with the braking system, just not the hydraulic side.