Trying to get a decent pedal, 42-46 Ford juice brakes up front, 57 chevy rear drum. 67 mustang drum/drum master with ch***is eng bracket and pedal. and 10lb res valve fornt and rear had an ok pedal, drove it in traffic, carefully, leaving room between me and others, and again no prob, although I can't gurrantee if i had to panic stop it would stop in time Rears are ajusted as follows: turn the star thing unitl brake lock, then back off 7-10 clicks so slight drag is felt. Front ford brakes are the kind with the 2 adjusters on top the 11/16 cams, bottoms are fixed, and I adjusted them to drag as well, maybe more drag than not like 1/2 to 3/4 turn when spun. Two dayd ago seemed to lose some pedal ,so me and jr do the 3 pumps and hold brake bleed, and got what i thought was all the air out....drove to work today and had to pump once to get a good pedal...so tried to bleed again today starting with the wheel/cly furthest away from mc Drove again and same, with stampng down hard she stops but rears lock, front don't then I got the idea ogf trying my mitywac to re bleed the front, and after doing that now I have no pedal at all...WTF? plus now I stripped a bleeder but luckily I am close to macs autoparts. Any help is appreaciated. ps I just picked up a speedway disc brake set up with calipers and the wokrs including a disc drum master, and 2lb residual valve, anyone have experience on how long it takes to swap that over? I was planning on doing it this winter as it looks like I need to run all new lines up fornt but...
i thought you were supposed to start at the closest slave and worked your way away from hte master. hmmmm there are pumps that you just run a return line to the MC and letter go. that gets the air pumped out, then you do a final bleed just to be sure. i once knew a total nut case that put a few drops of red food coloring in the bottom of the reservoir with a syringe just as he pumped ****ing it in (an eye dropper might work). then he would bleed til he saw the red blur flush out, plus a few pumps more. bleeding and not getting results can be frustrating. my thoughts tell me to look towards the MC. if your not having any leakage at the slaves, they're most likely fine. You might have a MC that is internally damaged. get a couple stubby metal lines and flair fittings for the MC. run a few feet of clear line hooked to the line outlets around your engine and back to the reservoir ( make sure the ends stay under the fluid level. pump it and see if air is being introduced. you can also plug the lines and put it under moderate pressure. wear eye protection of course. or, put another MC there for a bit. trial by elimination is still acceptable in shade tree mechanics circles lol As for the height. i had a car with the MC under the floor inside the frame. pert near the same as the slaves. makes one wonder though.
Bleed from rear to front -- After you fix that bleeder, pump up the pedal and jamb a stick between the seat and pedal holding pressure, crack the right rear/ close bleeder, then repeat 2 more times...now the left rear...top off brake fluid every fourth bleed. I gave up on the mightyvac, it seems to pull air through the bleeder threads, always seeing bubbles
this works for me get a piece of clear tube that fits over the bleeding ****** crack the ****** place the other end in a clean gl*** jar with enough brake fluid in it to cover the end of the tube go back to the peddle and pump go back to slave and see if the tube is full of fluid and no bubbles if so lock of the ****** move on to the next slave keeping an eye on fluid level in mc good luck
^^^^^thats how i do it.but i usually pump the brakes till the jar is full than dump it back it the mc.start with the farthest brake{p*** rear}then ds rear,front p***,then driverside.i dont understand the res valve unless the mc is under the floor.you mightt also want to put in a porportioner valve{SP?}they sell ajustable ones.
the mc is under the foor, attached to the pedal ***embly, ,I am ***uming that I pulled air into the system using the mityvac, and lost my pedal that way cause after bleeding with the mity vac I had the pedal go tot eh fllor and cannot pump it up at all...
I use a pressure bleeder and do all four at one time. My the master cylinder is located under the floor. Are you sure that the fronts are adjusted correctly? Pat
no, I am not sure they are adjsuted correctly...I adjusted them with a good drag, using the two cams on the backing plate. My thought was the closer to the drum the shoe was the better force when braking, maybe that is wrong.
I always set my brakes with a slight drag to start. You used a mighty vac? I use a mighty vac almost all the time and never have a problem with it. it is a little hard to tell of you are getting all the air out unless you are accustomed to looking at the hose. You have to keep a close eye on the master it will **** on dry in a heart beat. You said you lost brakes in the front. This is the ultimate dumb question but have you looked in your master? you have brake fluid right? You should always start bleeding at the farthest wheel cylinder from the master and work your way up to the closest. We just had a problem with a disc and drum setup on a '48 Ford and discovered that the pump rod was too short. It was doing the same thing locking up the rrears and not the fronts. But it was a power setup on the forewall maybe yours is all right. Be worth checking. You should be able to change out your fronts for the disc setup in a weekend. But I would make the drums work first just so it doesn't kick your ***.
If the MC is below the wheel cylinder(s) level, you need 2# residual valve(s) to keep the fluid from draining back to the MC. Using a MITY-VAC to vacuum bleed is not always successful as the bleeder screws are NPT and as you open them air will be drawn around the threads relieving the vacuum draw. I think you said (is this same thread?) that you are using a FORD OEM drum/drum MC. If so, the 10# residual valve(s) should be included in the MC. External 10# is not needed.
I think what I will do is get 2 new bleeders from Macs autoparts today, and re bleed the front. I did have fluid in the master, and with the cover off and pushing the brakes I get a big stream of fluid out of both front and back of the master....
Well, i went and picked up new bleeders for the front, I am going to check the adjustment again, check the system for leaks or loose fittings, and try to re bleed the front again... I was auing the three slow pushes on the pedal and hold method, loosen the bleeder, watch the fluid/bubbles and close the bleeder, then have the pedal let up, but I know he was letting the pedal up with the bleeder open, so...try it again.
Suspect a bad wheel cylinder or cracked or improper flared line. Try conventional bleeding techniques, clear vinyl hose and a clear jar with an inch of fluid in it. Connect one end of the hose to the bleeder and the other needs to be submerged in your clear fluid reservoir. Have a helper push the pedal as you open the bleed screw on the down stroke of the pedal. Close the bleeder and have the helper let up on the brake pedal. Do this for three or four cycles, if you notice one wheel producing more air than the others, that is where you start looking for the issue.
Those Ford front brakes can be a bear to get adjusted right. If they are not adjusted up just right it will act just like there is air in the lines. The first pump takes up the extra play and the second pump gets a pedal.
If that's still true, I'd suspect a problem at the master. & it may be a brand new problem . I would start from square one by isolating the MC and bleed it to satisfsction before going any further. You can replicate bench bleeding while its still bolted in the car.
what would the proceudres be for bleeding the master in the car? disconnect the line and run hoses to the bores, push the pedal and watch bubbles? thanks
If you are not carefull with the Mity Vac you CAN collapse the wheel cylinder. Then you'll have to "pump it back up" before the brakes will work again. This won't happen often, but it has happened to me.
I may have done just that, I could have ****ed those ****ers in to much...I think I am going to take each wheel off and check the wheel cylinders, then bench bleed then bleed the fornt....
just finished round 1 in the garage he is what I found. When I first ***embled the brakes a long while ago, I did not realize that there were two types of shoes on early ford brakes. The long shoe or leading shoe goes with the larger part of the wheel cylinder, and the shoe with the short material goes toward the back. Me being the genuis that i am or was, matched them per wheel so I had two long shoes on one side and two short on the other. So I changed them to the way it should be, and then adjusted the brakes again, and this time feel that the brakes were adjusted correctly. The wheel cylinders appear fine. Bench bled the master cylinder and there were some bubbles in the front section, so I should be ready for part two of re bleeding the brakes....
If your master cylinder when installed in the frame is pointing anything but downwards you'll never be able to 'bench bleed' it in situ as the air will have nowhere to get out. Raising the front of the car might help you though - i'm ***uming the underfloor m/c is pointing rearwards. Even if it's level or slightly downwards it might not be enough to get any trapped air out of the port (which isn't at the end of the cylinder, so all too easy to get trapped air). I'm not familiar with the adjusters, but if they're the type that aren't suituated between the cylinder and the shoe (ie the ones that move the shoe out but effectively leave a gap between the cylinder and shoe) then the bleeding action can be lost in the cylinder as it is allowed to move in and out. Bleeding with the brakes fully unadjusted or with the drums off and the cylinder wired or clamped closed should fix you up. Brake problems can be a real headscratcher Chris
The rear brakes are self energizing, the early ford front brakes are not. The rears will lock with much less pressure, so a way to balance front to rear pressure may solve the lock up issue.
To Clarify - A #2 RESIDUAL PRESSURE VALVE is only needed on a drum circuit if the normal #10 valve (drum brake) is not used for some reason. It would be needed on a disc circuit as a disc circuit does not use or need a RPV. The #2 valve prevents line fluid leak-back to the MC lower install than the caliper on a disc circuit. To check a master cylinder for proper bench bleeding or possible failure, used block-off plugs @ the MC line(s) outlet(s) to see if there is a hard pedal. Then go through the system bleed. I hope that made sense and was entered to clarify my earlier post.
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