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Power drum brakes problem

2317 Views 11 Replies 3 Participants Last post by  atxrhino
Hey guys i'm working on my buddies 65 mustang and decided to upgrade to power drum brakes, he will upgrade to disk later. He got the ssbc a28143 1965 FORD MUSTANG SSBC Master Cylinder and Booster Assemblies A28143 - I hooked it all up to the back port at first because i didn't have the fittings to separate all the brake times. I bench bled it like your supposed to and when i hooked it all up there was a bunch of air in the lines (bled 5 or 6 times each). i decided not to mess with it any more and just got buy the proper fittings. I have the front cylinder on the MC going to the back brakes and they bled just fine and no longer have air in them. The fronts how ever still have air no matter how many times i bleed them. I checked for leaks and tightened all the fittings and still have air. I re set the tension on the brakes and still have air. My last guess is the "T" to split the front to lines. Also i changed all of the brake cylinders and none of them leak. Any one have any idea what could be wrong?

Thanks in advance Garrett
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How are you bleeding the brakes? I use a small vacuum pump at the bleed screw, as I found it to work much better than having someone push the pedal in for me. Also do the one furthest from the master first, followed by the next furthest until your done.
That's how i bleed them minus the pump. I had my friend pump it 5 times and hold it then i would open the line and shut it. even when i just had fluid coming out for a pump or two the brake fluid was aerated
Oh crap I remembered it wrong, exactly opposite.

Q: What is the proper sequence in which to bleed my brakes when using the Mityvac® pump for vacuum brake bleeding?

A: When using the vacuum bleeding method to bleed brake systems on vehicles which are rear wheel drive the sequence should start with the wheel closest to the master cylinder and end with the wheel which is farthest from the master cylinder.

I suggest using the vacuum method. It's a lot easier and hasn't failed me yet. The pumps are cheap and they are an essential tool for many types of repairs on these old cars.
hmm ive never heard that but i will give it a try and see if it works better. at this point in time its worth trying all the small tips like this
So i bled the brakes from front to back driver to passenger and still had air problems so i decided to double check the hoses on the front and found the passenger side rubber hose was bad. i replaced it and the "T" but i still have a lot of air in the lines. Could the booster already be bad?
The booster doesn't have anything to do with air in the lines.
Why replace just one hose? Replace all three. If one is bad chances are the other are the same age and therefore same level of deterioration.

What about the lines themselves? If they are old just replace them.
The line i replaced was the only old line that he didn't replace. Do i need a proportioning valve? The car didn't come with one but i just ask my boss because he's a retired mechanic but says going from a single cylinder Mc to a dual cylinder i need one
You probably don't need a proportioning valve with drums at all corners. I don't have on any of the ones I've converted from single to dual, and I've done an F100, a Mustang, a TBird and a Galaxie.
If you bled the brakes from front to rear, you are doing it wrong. You need to start at the fartherest wheel from MC, passenger rear, then move to driver rear, then passenger front and last driver front. You may need to bench rebleed the MC before you start bleeding the wheel cylinders. I have seen it take a long time to get all the air out of the MC. Be patient when bleeding the MC so as ensure that you get all the air out before hooking up the brake lines.
@computerwise. it bled better when i did that because i just replaced the MC and booster. But still did not fix it with doing that.

I have fixed it now and found out there was a small leak on the passenger hose then i gravity bled them for 30 minutes and i have brakes now! thanks for the help guys.
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