JCMC64

Can someone tell me how to bleed this style MC with the installed M\C bleed screws? (bleed screws have the black rubber caps on it in this pic)
THX.

MDchanic

1. Remove it from the booster, so that it's level, instead of pointing upward.
2. Keep it level.
3. You should be able to bleed it from the bleed screws, IF you have the holes where the lines connect blocked off.
   In practice, this may mean putting those little plastic bleeder pieces into the line connections anyway, just like you would do if you didn't have the bleed screws.

If it were me, I'd bench bleed it as though there weren't any bleed screws, then bleed it from the screws, then install it, then bleed it from the screws again when you are bleeding the whole system.

- Eric

JCMC64

THx Eric.
I was leaning towards bleeding it traditional way too...but I'd like to know how the bleed screws on the M\C are supposed to work.

SO I know how to bench bleed normal M\C. But I dont quite follow how the bleed screws work in your steps below.

1) If I do it the traditional way, what would loosening the bleed screws do? Isnt all the air out already from traditional method?

2) If I just did bleed it using these Bleed screws, not traditional way, do I just loosen bleed screws after pumping the brake shaft, bleed it into a jar, back into M\C reservoir? Bit confused on this method.

Traditional way is more straight forward.

MDchanic

1. Loosening the bleed screws might get the tiny bubbles of air trapped in the passages leading tot eh bleed screws out.

2. Yes, but of course you can't bleed it using only the bleed screws unless the output ports are plugged, and they can't be plugged by the lines because the M/C has to be bled level and the mounting point in the car has it at an angle, so since you have to plug them, you might as well use the little plastic bleeder plugs that came with it.

As far as how, follow the instructions that came with the M/C.

- Eric

66luvr

I recently did one of these with a front disc conversion. The instructions did say to bench bleed it like all others and ignore the bleeders, so I did. Worked perfect.

JCMC64

Thx guys.

The M\C was already off the car on the bench, just grabbed a quick photo that I already had when I mocked it up.
The M\C instructions that came with was generic, mentioned nothing about the bleed screws...in fact it said to loosen the brake lines directly to bleed air after bench bleeding and installing to booster!

I went ahead and bench bleed the traditional way, and installed it. Still dont get what the bleed screws are good for at all, but will experiment when I get to point of bleeding entire brake system. Just got the Brake pedal back from powder coater, will install it this weekend.
Thx again.
Jim

spate51

Use a vacuum bleeder to pull the fluid through the MC screws. Gets all of the air out of the piston ports. Then bleed the brakes normally. Can be done with the MC on the car. Just keep fluid in each part of the MC

Allan R

Jim, to answer your original question<--> You put a clear plastic line on each of the bleeders and run the line back into the primary and secondary wells of the master cylinder. Crank the bleeders wide open and bleed away. When the front well shows you have all the air bled, close that bleeder. That will help force out any air in the back well a little faster. Bleed till no air in the line, close the bleeder and close the top of the MC.

I've been lucky bleeding my MC - it purged the air really quickly - less than 5 minutes. But it didn't have those bleeders on it either.

JCMC64

Alan/Spate....I get both ideas.
Alan, this basically allows you to bleed m/c hooked up in the car, correct? But what about the m/c needing to be level?

Spate... in researching bleeding the brakes I came across The method you describe, as well as pushing the oil up through the calipers using a pump. These ideas certainly sound like the best way to go if you got the pump. I didn't have the pump and I wanted to get it, but I was too impatient one night and just did the whole thing that night.

Thanks for the inputs