car has been missing the passenger side rear caliper for years. i drove the car home and it had very soft pedal and no braking power.

i put a new brake caliper on the rear and replaced both rear rubber hoses. i get good brake fluid from the front bleeders but nothing from the rear. i mini vac the rear lines and removed all the old brake fluid so they are empty. tonight i replaced the fluid and bench bleed the m/c. the front res. is shooting fluid fine. the rear res is not flowing much. i got all the bubbles out and started to bleed with the mini vac from the rear inner bleeder. no fluid and mini vac would not hold a steady pressure. i did get some fluid flow by pumping the pedal while hooked up to the mini vac. alot of air not that much fluid. after removing the mini vac i got a litle brake fluid out of the caliper on the first pedal pump then nothing after that. so i cracked open the rear brake line leaving the dist. block and got a little rusty looking fluid. not much, just leaked out a little, no pressure. broke the front line going into the dist block and got a good air / fluid sound. no air sound from the rear line leaving the distr. block. i broke the rear line loose leaving the rear res on the m/c and got no pressure or fluid. the front res on the m/c had fluid and pressure. is my m/c bad? or am i doing something wrong. thanks

 

sorry, 71 power disc ls-5 car auto if it matters.

 

also, brake pedal has a slight rough spot at the top and near the bottom of the stroke. not sure what this is but the pedal stroke is not smooth as silk. this is on every stroke.

 

Sounds like a bad M/C to me. Is it new?

 

new to me. lol it looks original. thinking i might try and rebuild it. or replace and store it. just not alot of fluid flow. i don't really have the plugs to check it right but the flow to me seems weak. plus a lot of rusty lookin fluid out of the brass metering block. since brass doesn't rust i'm thinking rear res. on m/c is rusty.

 

That's a fair assumption. If there's rust particulate in the system it could definitely plug up some stuff, and will probably end up in the cailpers (which isn't good either). We have new m/c's available if you're considering replacing.

 

Is it a ditribution block or proporting valve in that car? If there is a proporting valve driving it without rear brakes causes the valve to lock the flow of fluid to the front brakes only. To get the valve to return to center you need to release the pressure in the front calipers. Bleed the rear first.