Understanding brake system on 280ZX

[mzllodr]

The brakes on my 1980 280ZX have become very difficult to stop my car. Pedal is hard and all, but car won't stop quickly.

Took it to my Nissan dealer, he says the brake fluid was black. He flushed the system, checked that the power system is working and O.K., the discs are O.K, checked that the calipers are all working, (pistons going in and out) but he says only one caliper is really working well and O.k., (will slide that tire, but he says the other 3 corners seem weak).

He doesn't know what is wrong, he says maybe the master cylinder, the proportioning valve, bad brake hoses or ????

I checked the system diagrams and I don't see any proportioning valve, looks like the master cylinder does that job. Am I right ??

I'm ready to replace the 4 brake hoses and the master cylinder, all 4 wheel brake pads, anything else I should consider ??

Appreciate your help, I can also be reached at mzllodr@iowatelecom.net

Thanks

**** Brees

[RogerZ]

doesn't sound like that nissan dealer knows a lot if he can't diagnose a simple hydraulic brake system I'd go elsewhere. You can take the calipers off and see if they are free. You should be able to turn the piston. there are bosses on them to turn them down when you install new pads. If they don't move then they don't self adjust and you don't get full pad pressure when you push on the pedal. Did they fully bleed the system and displace the old cruddy brake fluid. Check auto parts stores for rebuilt calipers they aren't that expensive. Replace them all. Check hoses to see they haven't collapsed. Again not a real expensive item to replace if you do it urself. Rear brakes on my 83 turbo would not self adjust even tho I took them apart and freed everything up that I could get to. remember your car is old enough to drink legally in most states.

[zbane]

Agreed-you might as well change all those brake hoses, just be sure to use flared wrenches, and hit the connections with some PB Blaster before you start the job. I found the job to be easy and straightforward, as long as you have everything you need beforehand, though I only had to deal with one caliper.