74 260z brake question

[russo]

I did some searching but not sure which avenue to persue. The brakes have been neglected for years, probably 10+ since last fluid change from the completely brown/black fluid that came out today. along with some particulate.

The symptoms are that the pedal goes down about 3-4 inches without any reaction from the brakes, then it starts to brake during the last 2-3 inches of travel and will stop the car but you have to stand on the brakes. my calf actually hurt after driving for a few days to fix a carb problem.

So should i look at the pushrod length and verify it is set correctly? do I have a booster or M/C problem? The car is my father in-laws that will eventually be given to me and my wife but he wants to enjoy the car until then. Any suggestions would be greatly appreciated.

This winter the car is getting an overhaul, all new bushings, shocks, interior, and brake work for next season.

[Zs-ondabrain]

Some of this will be :stupid: obvious so consider it a "Check list"

Inspect the vaccum hose from the intake's ballance tube, to the firewall, then from that valve to the big vac booster behind the master cylinder.

You can also pull both end off and test that valve on the firewall, air should only go toward the motor and not towards the vac booster. Replace if bad.

Pads are cheap and easy to instal.

Bleed the hell out of all 4 corners.

Once the brakes are bled and the fluid is topped off, try the brakes again. Master Vac Boosters can and do go out. You can also check the push rod on the backside of the pedal. Use a 12mm? open end wrench and crack it loose. Spin the rod clock-wise so the rod goes towards the booster, but make sure the rod still has enough teeth on the pedal bracket to not fall off, then retighten.

Look for leaks around the Master Cylinder (MC) and the firewall behind the booster. might be time for a new MC. They're pretty cheap (around $30 or $40) and cheaper if you use your old resevoirs on the new MC. Just clean the hell out of them before swapping them out.

You can also adjust the outer rod of the booster into the MC but make sure they are Just Touching each other. You can gauge this by using some thick grease on the end of the rod and see how smooshed the grease is when you pull the MC back off.

Hope this helps, at least a little.

Dave

[Neumeier]

Dirty brake fluid is a bad sign. I recommend replacing the master cylinder, rear wheel cylinders, rebuilding the calipers, and replacing all rubber brake hoses. It is not so expensive if you do it yourself. Brakes are important!