Hello,

I'm trying to troubleshoot my "mushy brakes" problem that I have with my 89 Maxima and was wondering if any of you guys would happen to have a picture of a properly functioning master cylinder installed in a 3rd gen Maxima.
It would be helpful if the picture(s) showed the brake line connections and the connection to the brake booster if possible. This is the second master cylinder that was installed and I can't think of where else the problem may lie as the rest of the car's braking system was replaced except for the power booster (which should make the brakes harder to push instead of softer if there was something wrong with it from what I've read).
My google searches turn up a bunch of parts sites and pictures of the individual part.

Thanks for taking the time to read this odd request

 

I would say check for vacume leaks first on the car being that it is so old and could be part or the problem as you said that the unit has already been replaced once. And it's cheaper...

 

maybe redundant, but how do you know that you master cylinder is gone? Not much help I know, but have you tried to bleed the braking system thoroughly? inspecting brake hoses? checking to see if the connection from the master cylinder to the booster are not cracked/chapped?

 

check your lines for drop in fluid level. if you have a leak in your lines somewhere, fluid level should drop as you drive more and more. check area around master cylinder and booster. see if theres any corrosion around there. with the car off, press on break pedal, it should stiffen up to the top, start up your car and it should drop a bit. if none of the problems occur, you prolly just have air in the system/ or your system is contaminated. also it is fairly important that your brake fluid is throughly flushed from the system when you install the new master cylinders. otherwise there could be contaminants damaging the seals.

 

stupid question:
Have you bled the brakes correctly