Alright guys, here's the deal. It's a 1974 bronco.

1st I change from drum/drum to manual disc front/drum rear on the EB axles

2nd changed to full widths 44/9" with ford disc front/chevy disc(1/2 ton truck)rear.

I bought a new booster/MC from ebay. Mounted it all up and no good pedal!
I put the old f250 MC I was using w/manual disc(on the EB axles) and had a great pedal-problem was the rear brakes were dragging really bad...rear smoking after 1 mile run!
So I did what others said, and bought a lincoln MC from a '79 mark V. I could never get a good pedal. I bled,bled,and bled...still no luck! I counldn't even get the front to gravity bleed! So today, I thought I would try yet another lincoln MC from the store-thinking the one I had was faulty. I installed it, bled the system again...no F*cking brakes still:mad3: I even eliminated the H-block mounted to the frame using unions. Now there is just lines from the MC to the fron and rear main brake lines(nothing else). I bled everything again-still no brakes. I have adjusted the pedal rod 'til it feels right over and over. Still no brakes. I have to pump atleast 4-5 times for a somewhat firm pedal, let it up and hit them again- no pedal!!:shaking:

WTF!!!!
heres a pic for those that need something to look at while reading!:flipoff2:

I would like to fix this today, gotta do some local wheeling tomorrow!!!!
http://img.photobucket.com/albums/v319/dbuhrmaster/IMG_0066-1.jpg

Are you bench bleeding these MC's before you ever install them??

Are you bench bleeding these MC's before you ever install them??
yes! once I've done that, I have gravity bled, then go back to bleed them with help from a bud pumping the pedal.

Hmmmm...

I had this problem once.....

I ended up haveing to use air to completely blow all the old fluid out of the lines, and start all over.

Try to bench bleed again, and make the fluid recycle back into the MC (use hoses to put it back in), one bench bled, try to gravity bleed again, when fluid comes out, close it off and give it an hour or 2, and then pump the pedal.

If that doesn't work, try blowing the lines out and starting over.

Is the booster any good?

Hmmmm...

I had this problem once.....

I ended up haveing to use air to completely blow all the old fluid out of the lines, and start all over.

Try to bench bleed again, and make the fluid recycle back into the MC (use hoses to put it back in), one bench bled, try to gravity bleed again, when fluid comes out, close it off and give it an hour or 2, and then pump the pedal.

If that doesn't work, try blowing the lines out and starting over.

Is the booster any good?
the booster is new, and seems to work just fine. I just adjusted the pedal rod out as far as I can go-to give me the most travel on the pedal. I'm waiting for some more fluid to show up so I can bleed it all over again! I know this will not fix it...I'm sure there is no air in the system. I have bench bled the MC's twice each! I guess I will have no choice, but to slap the old f250 MC on again, then figure out what the hell cause the brakes to drag so badly!! I was hoping for more input from others. I guess I should have posted this in general...seems to have more traffic. Did I mention, all the lines are new?

You do have the bleeder screw at the top of the caliper correct? Try taking the calipers off and turn and tap them to get any air out.

You do have the lines hooked up to the proper ports right? I know on some MC the front port is not the front brake.

Is there a loop in the lines where air could get caught?

I know these are basic questions but sometimes the simple things get overlooked.

It sounds like air in the lines or MC, keep after it, you'll get it sooner or later.

Brewchief:D

You do have the bleeder screw at the top of the caliper correct? Try taking the calipers off and turn and tap them to get any air out.

You do have the lines hooked up to the proper ports right? I know on some MC the front port is not the front brake.

Is there a loop in the lines where air could get caught?

I know these are basic questions but sometimes the simple things get overlooked.

It sounds like air in the lines or MC, keep after it, you'll get it sooner or later.

Brewchief:D

I mounted the rear calipers so the port in straight up. There is a loop in one of the front lines. I couldn't find the right length yesterday, so i cheated...wanted it fix right away. I never have any luck flaring the lines..so I put a small loop in the pass side front. I can get them to gravity bled, a nice stream out of each wheel. I have even removed the calipers to lower them and bleed the system that way. Go figure!!!

bla bla bla, bla bla brewchiefs avatar...bla bla. Sorry Chuckroast couldn't resist! :eek::flipoff2:

what a huge difference!!! I haven't tried everything out just yet, but now I have a pedal-A firm pedal! I'm sure this is the fix.

To clue all those who are wondering whats up...a buddy suggested I check the length of the rod going into the MC. Well, I've already said the f250 worked good, but nothing else would.

I measured the depth of the hole on the f250 (1.375") and the lincoln was (1.415"). So I began inspecting the rod going into the MC from the booster bracket...it has a small adjusting bolt/lock nut:shaking:. I screwed this out a few threads(about 4turns).

Wahlaa!!! Firm pedal! I will still test everything out good, and post the results...Thanks A bunch ED!!Chuck

Most of your problem is the residual pressure valve. A MC meant for disk/drum will have one valve, a drum/drum will have 2 valves. A residual pressure valve on a disk setup will cause the calipers to drag. The valve is a rubber nipple on a spring under the brass cone in the port on the MC, use a screw and a pair of dikes to remove the cone, spring, nipple, and reinstall the cone.

Most of your problem is the residual pressure valve. A MC meant for disk/drum will have one valve, a drum/drum will have 2 valves. A residual pressure valve on a disk setup will cause the calipers to drag. The valve is a rubber nipple on a spring under the brass cone in the port on the MC, use a screw and a pair of dikes to remove the cone, spring, nipple, and reinstall the cone.
So I did what others said, and bought a lincoln MC from a '79 mark V.

its a 4 wheel disc MC...should be no valve. changing the length of rod made all the difference.