82streetracer

iTrader: (1)

alright, got all the GSL-se suspension and brake stuff into my 82.

Remaned calipers and Thermoquiet brake pads all around.

Stainless braided hoses.

New hard lines on the rear axle.

I rebuilt and honed the original SE Master cylinder. Bench bled the master on the car, Vacuum bled the calipers one at a time, twice in a row. pedal still goes to the floor. I get some braking pressure, which will stop the car, but not the rock hard pedal I should have. With the car running it feels like nothing is there.


so I get a new remaned master from champion. Bench bleed that and twice around bleed out the calipers again. felt about the same. then my buddy Mike comes over and we manually blead each caliper. Strong flow of fluid from each caliper and it is perfectly clear, no airation.


Still no pedal. So Im thinking maybe its the dot 4+ valvoline synthetic fluid Im using, its extra thin for ABS system.

So I flush all that out with some cheap Advance Auto brake fluid. Bench bled and vacumme bled.


still no pedal,


WTF is going on, I work as a mechanic and do brake work all the time but this makes no sense.

Ill be getting a 3rd master cylinder in by the end of this week.

Its either the master, or the proportioning valve

the proportioning valve is the only thing I did not replace, I sprayed some brake cleaner through it, as I looked pretty dirty. but why would that give me a dead pedal?

GavinJuice

you sure you have no air between the MC and the PP valve?

85rotarypower

Bench bleed the master on the BENCH, then install it on the car. After that, manually bleed each caliper the old fashion way, starting with the one furthest from the master cylinder. If that still doesn't solve your problem, look into the brake booster. Mabey its got a problem?

$100T2

iTrader: (1)

And don't push the pedal to the floor when bleeding the brakes, that ***** up the master cylinder. Never go more than halfway down when bleeding.

82streetracer

iTrader: (1)

Why on a bench? it looks like its sitting level on the car, and its a lot smoother with the pedal than pushing a screw driver. and the brake booster is working, although I can tell it has a leak, pedal movement has an slight effect on idle.

but the pedal should be rock hard with the car off, and really firm with it on. It is really soft.


I put a new master and two new calipers on my Ford Probe, and had no problems like this. I didnt even bleed them as thoroughly as I have here, with much better results.

I only really used the pedal when bleeding the master. I could see the flow of fluid and bubbles, and the front brake side would flow first, and the rear side coming on about halfway down. they didnt seam to flow at the same time.

I had the LF caliper line hooked into the master when I was bleeding it out, but it was already full of fluid.

GavinJuice

What?????

82streetracer

iTrader: (1)

yeah, Ive never heard that either.

and does someone know the bleeder thread sizes, im looking to get some speed bleeders

imabyter

WE did a group buy of SpeedBleeders with some friends and guys I work with, and everyone threw them away within a year. They like to leak around the threads so when you let off of the pedal, air gets sucked around the threads. I tried teflon tape and pipe dope, but could never get them to hold solid.

If it is a once every couple of years thing, they might work, but I bleed 7-8 times per year (I do a lot of track events) and the Speed bleeders just don't hold up.

perfect_circle

what exactly is bench bleeding??

OnlyOnThurs

^^When you bleed the actual master cylider out side of the car (not installed).

82streetracer

iTrader: (1)

not necessarily, it usually refers to bleeding the master while its not connected to the rest of the system.

and I dont plan on using the "Speed bleeder" brand, Russle just came out with a new one, where it has a spring loaded conical seat, instead of a check ball. ALthough fluid may run through the threads, it is getting sealed at the cone and not in the bleeder.

Dan_s_young

iTrader: (1)

Huh? That makes 3 of us that have never heard of this (and I should mention im a mechanic as well...). Who told you this and whats the reasoning behind that? I've bled brakes many of times and NEVER, had any problems pushing the pedal to the floor.

Dan_s_young

iTrader: (1)

Are you making sure to pump the brake pedal multiple times (until the pedal is stiff) between opening up the bleeder?

Stanly08

I would get some plugs that would screw into the ports on the m/c and after bench bleeding it, block off the ports. Then if you install the m/c into the car and try the pedal (gently) it should be hard and not go down at all. Then Hook up the line to the rear brakes and bleed them and try the pedal again. If it is still hard, then hook up the fronts and bleed them. This may help pinpoint where your problem is.

trochoid

iTrader: (6)

Just venturing a guess here, but it sounds like you may have a bad fitting somewhere in the system that is sucking air back in.