New brakes set up, I bench bled the MC, and everything plumbed tight. All 3/16" ss lines, no residual valves, all discs, and the dual MC came from hotrodusa designed for all discs. Tried traditional bleeding with pedal and with hand pump vacuum, and having a tough time getting all the air out. Car is level, MC is high. So I thought I would try gravity bleeding. Topped off reservoirs, opened bleeders, and half a day later, the reservoirs haven't dropped at all. Are 3/16 lines with 028 wall too thin for gravity bleed? Is there some valving internal in a disc/disc designed MC that is stopping it? Should I just wait longer?
I gravity bleed all my junk, even 3/16 lines. Close all your bleeder valves and pump the pedal a bunch of times. Then, reopen the valves and that should work. Sometimes they get air locked and will not bleed without some agitation. My 63 truck is that way. Once the fluid gets to moving you should be able to do them fairly quickly. I always just sit in a chair and drink a Coke or something. Look under the car every 5 minutes or so to check for puddles under the wheels. Once you get a nice puddle forming, close the valve and that wheel should be done. Continue until all 4 have run freely. It goes without saying, but be diligent keeping the master cylinder full. Once all 4 start dribbling, it can empty pretty fast.
i dont have the patience for gravity..if you werent able to get it by doing it manually..somethin aint right.. maybe the MC is ****? not sure on the "stopping it from gravity bleeding question" ive never had that much time on my hands
First, make sure the master cylinder is returning fully (should have '040"-'060" play in the push rod). Second, leave the cap loose but covered to allow normal air PSI. (I would only do this in very dry climates, as you want to minimize any moisture contamination). Use Tygon clear tubing, either 3/16" or 1/4" ID, to fit on one bleeder screw cracked open at a time, and empting in a can/jar. (This can be found at any good hardware store). Have the Tygon run above the caliper before going down to the can, as this slows and allows visual fluid and/or air flow, and works great anytime when pressure and/or pedal bleeding. The 3/16" brake tube is not too small, and there should be no other internal valves in your disc/disc master. In addition to my first sentence, make sure your master bottoms out before the pedal hits the floor, as this is a new system. If the master cannot be fully stroked, you might not ever get a good bleed. One thing you didn't memtion, what kind of fluid are you using? DOT 5 will require more patience, ie slow pedal movements. Bob
Sounds like you may still have a leak somewhere or the byp*** port in the MC isn't getting uncovered or is plugged up. Gravity bleed should only take a few hours and vacuum or pump/crack bleed should always work with a conventional setup.
okay, i got it.... after waiting a half day of trying to gravity bleed, i went back with the traditional pedal method, and it worked great ?!? kinda weird, maybe it burped a phantom air pocket or something. thanks for suggestions. used DOT 3, and the MC was bench bled in a vice with the little kit it came with, using big philips to plunge and keep circulating until no bubbles. Bob- good point on the plunger return gap... that has bit me before.
I was never much for gravity bleeding (almost as good as watching paint dry) and with manual bleeding you have to have a good technique down and an alert person at the pedal. They have to know when to hit the pedal and not mash it to the floor. As the bleeding gets finer, they have to use less foot pressure. You can have some control at the bleeder with some precision cracking of it. Most of the time, I crack the bleeder, hold a finger over the end for the entire up & down thing, close it when that wheel is done. I figure on going around the car 3 x before I have it bled to my liking. Bob
Ever try the speed bleeders? They have a spring loaded check valve internally in the bleeder screw. You crack the bleeder, pump the pedal until you get flow, tighten the bleeder screw, done. Starting at the wheel that's furtherest from the master cylinder and working your way to the next closest and so on insures you get all of air out. I'm sure they are available elsewhere but I know Speedway has them. A couple of bucks more than conventional bleeder screws but the h***le they save is worth it. Besides it makes it a one man job. Frank
Easiest, cheapest one man bleed, just take the rubber cover from the bleed screw,with razorblade make small slice in it ,crack bleed screw on wheel cyl and pump brake pedal a couple times till all air is out. tighten go to next wheel ect. A little messy so put a rag over it as not to squirt all over. Let me know if it works for you
O'Reily has speed bleeders, mine were about $6 each, but I needed them that day, put 'em on my daily '06 Silverado, bleed out the brakes when I rotate the tires to get new fluid thru the calipers.
i'm having trouble bleeding the antilock brakes on my wife o/t.send me a p.m.as i know that is not what this site is for.but there are some pretty sharp folks on here that i trust more than most local guys and i would greatly appreciate the help.wife can't understand how i can completly rebuild the brakes on my59 chevy but can't fix hers.HELP
my favorite trick is to go to a farm store ,buy a horse hypodermic syringe,you don t need the needle part,get a piece of vacuum rubber tubing that fits on the bleeder valve and hypo snuggly,next next **** up some brake fluid in the hypo,crack open the bleeder valve,and inject the fluid into the wheel cylinder making sure no air is in the syringe.This will force any air left in he system backwards and vent out of the mastercylinder's open cap.When syringe is empty close bleeder with a wrench.....one man job,no drama or very much mess.
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