spelosi77

I recently purchased a 91 1LE Camaro. with 60K on the odometer.

The brake performance was very bad from the start.

The brake fluid was black as night.

I replaced the master cylinder and bled all the brake lines using a kit that I hooked up to my air compressor.

I bench bled the master cylinder before installing it on the car.

I did this once before on my first car, an 84 Z28... in 1996.

I stopped bleeding it when I stopped seeing air bubbles.

What I did see however and was unsure if it is correct is fluid squirting out of the front most reservoir when pressing in the piston.

This fluid is still squirting out of the front reservoir with the Master Cylinder installed on the car (to expect anything else would be silly, I know).

Is this a sign of a bad Master Cylinder?

The calipers are getting piston pressure but there's not a lot of stopping power.

Thanks.

rsmith085

iTrader: (1)

I've had new ones do that when I thought I was going to save some time by leaving the cap off the reservoir while bleeding. To me signs of a bad master are fluid leaking past the piston then it runs down the firewall/brake booster. Also brakes being impossible to bleed when doing it the old fashion way, the master will draw air into the system. Being a 1le it'll have the big rotors so it should stop pretty good. Maybe a stuck piston in one of the calipers or a hose collapsed? Also check that the caliper pins that the caliper slides back and forth on aren't corroded up.

spelosi77

The pins definitely have some oxidation on them. They are VERY tight. I don't feel like a lot of sliding occurs. Should this pin be lubricated?

I can't say I understand the operation of this system.

thanks!

rsmith085

iTrader: (1)

Yep, it's whats known as a floating caliper. What happens is when you apply the brakes it puts pressure on the pistons but because there's only pistons on one side of the caliper the caliper has to move so there will be equal pressure on both sides the rotor. The caliper is designed to slide back and forth on the bolts that bolt it to the caliper bracket. Clean up the caliper bolts and the sleeve that they go into and put some good high temperature grease on them. There should also be some little rubber boots to keep dirt out of the sleeves but they might be gone from age. You should be able to get whats called a caliper bolt/pin kit that'll have new bolts and the little boots in it down at the auto parts store if you want or need to.

spelosi77

The 1LE dual piston caliper pin does not have a boot. There is one pin on the bottom of the caliper and it's used to hold the caliper in place. The pin is held in place with a C clip. Removing the pin is the only way to service the caliper. Does this type of setup require grease?

rsmith085

iTrader: (1)

Them 1le calipers are different than I was thinking, I had to google it lol. Pretty much look for where the caliper makes contact with the carrier/bracket(should be some smooth machined places) and anywhere that it does remove the corrosion and put some grease on it. As for the pin I would imagine it would need some grease to but without actually seeing how it all goes together I can't say for sure. Maybe someone with some hands on with it will chime in?