Hi Folks,

I bled the master cylinder in my 68 Dart a while ago, using looped piping. I must have introduced quite a bit of air into the brake lines while I had them off, because after that I had literally no brake pedal (straight to the floor).

So I went about bleeding the brakes today. Bought a little kit with a clear tube, a plastic bottle and a magnet to hold it to the fenderwell. Here's what I did:
-Loosen bleed screw 1/2 turn, attached hose.
-Placed bottle above the upper A-arm.
-Had spouse pump brakes until bottle half full, then stopped.
-Refilled master cylinder.
-Emptied bottle while leaving hose attached and started over from step 2.

My problem is that I have been working on the front passenger side (9" drums all the way around) for several hours, and have gone through more than 32 oz of fluid. Still have air! Sometimes in fairly large quantities, sometimes will go a pump or two then end up with a large slug of air in the tube, maybe 1" long. There seems to be no end to this.

I have doublechecked all the fittings, they are tight and don't leak. I finally ran out of time this evening and put it back together. The brakes work fairly well, but they have been better!

Any thoughts on where all this air is coming from? Seems like once I got the fresh clear fluid through the line the air should have been gone, but that's not the case. Could it possibly be coming in around the threads of the bleed screw (heard this happen once, but realized I had loosened the screw way too much).

Could my old Dart be this air bound?

-Mac

Some air can seep past the threads on the bleeder valve.

Wrap them with teflon tape.

Then get a aquarium airline check valve (rubber flap kind, not spring load valve) to make a cheap DIY speedbleeder.

Keep Pumping......

BTW, once you're sure you've got all the old fluid out, you can reuse the fluid by putting back into master cylinder..........

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

Unles the hose has a real tight fit on the screw it can leak there and suck air back into the system when you lift the pedal.

Most people overthink brake bleeding. For years My method was to open all bleeders and pop master cyl cap until fluid flowed. Then had someone open the bleeder and I pushed the pedal down and held it until bleeder was tightened. you only have to do this a couple times per wheel most of the time.

If you have introduced so much air that it will not flow open bleeders on one end and pump pedal twice. I know people are afraid of taking air in on the upstroke but it wont matter. Once fluid flows close both bleeders and do the same for back wheels. When the fluid flows from the rear close them and proced with the process I described above.

Do not pump the pedal a bunch of times and then hold it till someone opens the bleeder. this is good for nothing but strengthening leg muscles.

I have a mityvac and a reverse injection unit but this way has always worked quicker and better.

remember pedal up,open bleeder,pedal down,squirt,close bleeder,pedal up open bleeder,pedal down close bleeder. reoeat this procedure a few times per wheel or as is necessary.

Useing this procedure you will have success every time unless there is a problem with a component.
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Ss
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