Brake Problem

Q: Brake Problem

Thanks for your input so far . I’m still undecided what to do. Is the master cylinder too small or is there a problem with the front calipers do you think? The brake pedal is going to the floor at the moment and the brake light on the dash doesn’t come on. With the two front flexible lines clamped off (near the calipers) the brake pedal is solid (it moves about 1″) and the brake light comes on when I press a bit harder. So that would indicate a problem with the front calipers? There are no visual leaks, but one of the members had fixed his problem by putting a kit thru the calipers when he had no visual leaks. Or is it simply not enough volume in the master cylinder? A local guy here quoted a couple of comparisons in Chev trucks he’d dealt with and it didn’t seem like the diameter of the m/cyl would affect things that much. The book does say 1-1/8″ though and mine is 1″. The way the brake warning light acts has got me too…… I have drums on the rear and the front are the 4 spot calipers that were an option.

How do I bleed those troublesome air gaps??

A: I still believe you have your calipers reversed from side to side, the left one on the right, and vice versa. I think the bleeder screws should be horizontal at the top of the caliper. If they are vertical, the end of the hole the bleeder screw is in may be at the top, but the other end of that hole in the bore will NOT be at the top! Therefore, big air pockets, which cause the brake warning differential light to come on when the pedal is pressed down hard.

If the bleeders are horizontal, maybe you have only half of each caliper reversed, so the air pocket is not happening at the caliper half with the bleeder, but at the half with the steel tube connecting from the other half. You have to imagine where the drilled holes lead to inside the calipers to get what I’m stating, or maybe just disassemble the calipers to see where those holes are relative to the piston bore. If they are reversed, you’ll be taking them apart anyway!

ps the size of the master cylinder bore is NOT YOUR PROBLEM!!

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