LaGSaLoT

For the past month or so I have been having to refill my brake fluid reservoir every week and a half. First I thout maybe one of the bleed valves on the wheels was lose, so I blead my brakes and tightened them up real nice. Still leaked. I checked my master cylinder for leaks and I couldn't see any noticeable ones. This problem is for my front brakes only so I was wondering if I should replace the Master cylinder or what? And where could I find a new or rebuilt one for a decent price, I just want to replace it because I am a daily driver and don't want to get in a wreck because of a leak in my brakes. Any and all information is welcome.

Oh I was also wondering if I should invest in some of the steel braided hose lines that MSA has, would they be worth it or should i find some stock replacements?

fenderbender02

You should check you caliper pistons. Mine went bad and I found replacements at Autozone. So I replaced all four just to be on the safe side of course I didn't find this out until I had replaced ALL of my brake lines and hoses, master cylinder & resevoir. I found out because when I decided I must have bad brake pads I pulled the caliper off and the piston fell out. Hope this helps.

LaGSaLoT

Does the actual caliper itself leak? I mean I can break just fine when i fill up the resevoir. Maybe Ill check them out.

rifleman502

i just replaced a rear caliper and roter and all the pads, also purged the brake system and put all new fluid in... brakes work good now... my caliper was leaking out of the boot around the piston...
wow what a pain in the ***...

Bleach

To answer your question, yes the calipers themselves can leak a little and still function properly. The leak might get worse though and possibly start sucking in air. Also, if it gets bad enough, something could give while you are driving and you could lose enough fluid to lose brake pressure even if you checked your reseviour before you started driving. Inspect the calipers, quick!

Also, note that on the master cylinder the front resivour is for the rear calipers and the rear resivour is for the front calipers.

fenderbender02

I agree check it quick don't do what I did and come up to a red light at 40mph with no brakes at night. I had to cut across 4 lanes of traffic, jump a curb and get on the cross road and let it coast to the nearest parking lot.

Bleach

When this was happening to my Z a while back I would just fill it up every few days and that was fine. The leak was slow. Then one morning before work, I started the car and pressed the brake pedal to the floor. The leak had suddently gotten worse and at that point I had air in the master cylinder so it required a bench bleed. I had to drive my truck that morning.

The problem on my Z was the rear parking brake lever on the caliper. The inside was dry of grease. Every time I would pull the parking brake it would grind the hindge internally. After a while it started to let brake fluid leak from the back side of the cylinder through that parking brake hindge. These 82-83 rear brake calipers are always giving me trouble. I think they are a poor design. That is the second caliper I've had to replace due to a bad parking brake lever.

LaGSaLoT

I guess I will go ahead and take off my wheels and check them out then. it is my front brakes only cus when I bled the brakes, only the front ones had air in them, and only that reservoir was empty so I guess im half lucky, heh. Just hope that its somethign mildly cheap to replace because I work for minimum wage, in california!

LaGSaLoT

So I popped off my right front wheel today to check out the caliper. I dont have a jack, or hoist so it was basicaly on the ground. Looking at the piston their wasnt a single drop of fluid, so i dont think the calipers are the problem. I may take off the left wheel and check that out if i have time, but the right wheel took me like 2 hours to take off and get back together. My friend pushed the brakes like 3 times while the caliper was off the rotor so all the pressure built up and i couldnt fit the 2 pads back on. God that was horrid, sitting indian style holding the caliper up trying to force the piston back to normal position while not ripping the stock brake line off the caliper. I was so stressed out after getting the wheel back on that I forgot to tighten the lugs on my wheel for my drive back home.... LUCKILY I am not a crazy driver taking turns at 100, I realized this about half way home and started stressing out, so once i got home i busted out my tools and tightened them to saint swithens day.

Back to the main point, while doing the calipers my friend was looking in the engine bay for leaks. This being a 1979 vehicle, your bound to find leaks. He found a wet spot on the break line where the metal tubing attaches to the firewall. Its the first connection from the master cylinder to the firewall. He took off the bracket but the rubber peice was still on it. Could it be possible for the line to break in that area? I mean it is gaurded by rubber and a bracket and seems pretty tight.

AHHH man I need a garage so I can just tear my Z apart and fix every leak on it, so stressful. I need more input, perhaps one of you lives in the bay area and could come down and check it out with me to help me out, I am not a rich man so I don't want to take it to midas or whatever to have them fix it, plus I like to learn and gain experience from my own mistakes and whatnot.

fenderbender02

the rubber piece should be split so you can remove it. Could be there is a worn spot or something of that nature then. Let us know what you find.

LaGSaLoT

Ok I just loosened that peice and felt up the tubing, felt pretty damn dry and looked like new. So thats not where its leaking from. i think ill do a 4 wheel caliper check this weekend when I have the time, but if its not the calipers, where should I look next, that way I can get it all done on one weekend.

Bleach

Follow the brake lines from the master cylinder to each wheel and look for the dark oil spots. Luckily a brake fluid leak doesn't dry up like water. It'll stay visibally wet for quite some time. It could be leaking at any of the six rubber brake lines also. There are just two on the front, and four in the rear.

...or it might be leaking at the master cylinder. Did you check really good right below the master cylinder?

LaGSaLoT

well I had time today to check my left front, dry as dirt. Perhaps it is leaking from the master cylinder because the metal brake line is moist from the cylinder to about 1' of distance. Should i just start it up, have someone pump the brakes for a while to see if it starts leaking? Perhaps I shall..