MC question

[Billybobjunky]

So i'm puttin' power brakes on the truck and I got a question. I am pumpin the brakes and they are kinda resistent and then kinda plunge, but not to the floor, they plunge til they seem to "bottom out". I checked the MC and the front lines are gettin' fluid, but nothin to the rear line. Is the pushrod too short, I adjusted it b4 I installed it, or is the MC just bad? Any info on where to start guys? Thanks!

[fordman]

is it a new mc? if not it might have some crud in it. if it is did you bench bleed the mc? if not you need to get fluid through the mc before it will go into the lines and work. and you may have to recheck your adjustments i don't know what you have going on there.

[Billybobjunky]

the adjustable pushrod head is all the way in, like as short as it will go. it's an old MC so, possibly residue or whatnot in it? think it'd be easier to clean this one up or just buy a new one?

[fordman]

you should be able to clean it up pretty easy just bleed the heck out of it until clear fluid is running out of the mc. then reconnect your lines.

[Billybobjunky]

BLAHH!!!!! Is there something I am supposed to do to new calipers that I didn't know? I got good fluid flow at the bleeders, but the pistons just wont engage the pads!!! When I am bleedin power brakes, does the truck need to be running? Also happening with the back drums. I got fluid at the bleeders, but the wheel cylinders aint comin out, and they are brand new. what is goin on!?!!?!?!? I cant test drive this new motor til I got brakes....what is goin' on!!!!!!! Oh yeah....thanks!

[fordman]

that sounds wierd. no the engine doesn't have to be running. maybe the back brakes aren't adjusted out enough to catch. the front should squeeze togther if there is fluid going to them. maybe you haven't got all the air out of the wheel cylinder/ calipers. or maybe it has something to do with the proportioning valve.

[Billybobjunky]

could it have something to do with the pushrod length? maybe not enough pushrod, or too much? i adjusted it when I put it together, and the MC didn't sit against the booster. It sat about an inch out from the booster due to the MC and then i just bolted her down. I really don't understand brakes and it's drivin me nuts! I've been "test drivin" her through a course of strategically placed cinder blocks. I need brakes!