Hi - I have a problem with a braking system air leak and wondered if anyone knows of a diagram of the master cylinder and associated pipes online anywhere?

 

Symptoms are that the brake pedal is spongy, goes right down to the floor, and I can hear air escaping while pumping the brakes. Are there any known common faults?

 

Thanks in anticipation for your help as always :helpsmilie:

Yes brake servo has died - sounds like.

Check the hose running from plenum. Also, there is a valve on this hose, that lets

the air pass only in one direction, check that also.

 

I suppose that if there was a hole in the servo mechanism

you would get the outside air sucked in while braking.

Let someone step on the brake pedal and see if you can

suck air through the hose.

If you can breathe normally that would mean there's a hole

in the servo. On the other hand, if you suffocate then

everything is perfectly fine... :-)

Here are the sum of the parts..

 

http://www.courtesyparts.com/betasite/300zx-z32-1990-1996/genuine-nissan-parts/brake/470-brake-servo-servo-control/-c-882_883_982_989.html

Thanks very much Andy, will let you know how we get on :)

sounds like a problem I had and it was the brake booster that failed took me 4 hours to get it out and half an hour to get new one in:hammer:

My OH has had a look and reckons air might have got into the system from not having the brake fluid above its minimum marker, so we're going to bleed the system tomorrow, see if that cures the problem :-S.

 

Does anyone happen to know the order of bleeding the brakes? as in front right hub first, then rear left etc.

 

Thanks for your help - would be lost without this forum :)

furthest away from master cylinder(on servo) first, which is rear passenger side, then other rear, then front pass. side, and finally front drivers side. always longest pipe to shortest in order. hope this helps. Cheers.:rockon:

My OH has had a look and reckons air might have got into the system from not having the brake fluid above its minimum marker, so we're going to bleed the system tomorrow, see if that cures the problem :-S.

 

Does anyone happen to know the order of bleeding the brakes? as in front right hub first, then rear left etc.

 

Thanks for your help - would be lost without this forum :)

 

 

If the air ONLY entered the system from the low master cylinder level then you ONLY need to bleed at the ABS unit in the boot, there are two bleed nipples on the unit, do these first and see how you go.

 

Jeff TT

Hi guys. Just wanted to let you know that Jeff's suggestion of bleeding the ABS has cured my problem and I'm back on the road again :) Thank you all muchly :)