Brake bleeding without pumping?
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Brake bleeding without pumping?
I'm still dealing with brake problems. I called CIP1 for parts and advice. The tech guy described bleeding the brakes without pumping the pedal. As I remember it, he said first get all four wheels off the ground. Then loosen all four bleeder valves. Then making sure the reservoir is full, let the bleeder valves drip for a day or two. He suggested that will clear any bubbles anywhere in the system.
Anybody heard of that?
Kevin
Anybody heard of that?
Kevin
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I have a difficult time believing that it will work. The air bubbles will rise to the highest point and that is not likely to be the bleeder.
Pressure bleeding will probably work the best. However, letting the car sit overnight and bleeding again the next day might in fact help get rid of the last of the air in the system.
If you have old rubber brake hoses, they could be swelled nearly closed inside and could cause problems trying to bleed your brakes as well as braking.
If they are more than 10 years old I'd replace the rubber brake hoses.
Scott Novak
Pressure bleeding will probably work the best. However, letting the car sit overnight and bleeding again the next day might in fact help get rid of the last of the air in the system.
If you have old rubber brake hoses, they could be swelled nearly closed inside and could cause problems trying to bleed your brakes as well as braking.
If they are more than 10 years old I'd replace the rubber brake hoses.
Scott Novak
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- Zen
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Over the years, I've tried every method of brake bleeding known . . . pressure bleeding is the only way to go. It's fast, it's easy and it clears all the air PLUS all the old contaminated fluid out of the entire system.
You can purchase a proffesional pressure bleeding system, but it's really easy and cheap to improvise a pressure bleeder on a bug. I took an extra fluid reservior cap and drilled a hole in it and inserted a wheel valve stem in it. I made a seal for it from a piece of bike inner tube. I fill up the resevior with fresh fluid, put my valve stem cap on it and pump just a little pressure on the reservior (any more than "just a little pressure" could bust open that 30+ year old reservior . . . don't go crazy with pumping). I crack one bleeder screw and keep a little pressure on the reservior untill fresh, clean fluid is running out. Then I close that beeder and go to another, then another, then another. It works best with two people . . . one to operate the pump and keep an eye on the fluid level while the other runs around cracking the bleeders. Takes 5 minutes, tops. If you still have a problem with the brakes, it's not because there is air in the system.
You can purchase a proffesional pressure bleeding system, but it's really easy and cheap to improvise a pressure bleeder on a bug. I took an extra fluid reservior cap and drilled a hole in it and inserted a wheel valve stem in it. I made a seal for it from a piece of bike inner tube. I fill up the resevior with fresh fluid, put my valve stem cap on it and pump just a little pressure on the reservior (any more than "just a little pressure" could bust open that 30+ year old reservior . . . don't go crazy with pumping). I crack one bleeder screw and keep a little pressure on the reservior untill fresh, clean fluid is running out. Then I close that beeder and go to another, then another, then another. It works best with two people . . . one to operate the pump and keep an eye on the fluid level while the other runs around cracking the bleeders. Takes 5 minutes, tops. If you still have a problem with the brakes, it's not because there is air in the system.
- bugman742002
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Hey,what is the seal you mention ?Zen wrote:Over the years, I've tried every method of brake bleeding known . . . pressure bleeding is the only way to go. It's fast, it's easy and it clears all the air PLUS all the old contaminated fluid out of the entire system.
You can purchase a proffesional pressure bleeding system, but it's really easy and cheap to improvise a pressure bleeder on a bug. I took an extra fluid reservior cap and drilled a hole in it and inserted a wheel valve stem in it. I made a seal for it from a piece of bike inner tube. I fill up the resevior with fresh fluid, put my valve stem cap on it and pump just a little pressure on the reservior (any more than "just a little pressure" could bust open that 30+ year old reservior . . . don't go crazy with pumping). I crack one bleeder screw and keep a little pressure on the reservior untill fresh, clean fluid is running out. Then I close that beeder and go to another, then another, then another. It works best with two people . . . one to operate the pump and keep an eye on the fluid level while the other runs around cracking the bleeders. Takes 5 minutes, tops. If you still have a problem with the brakes, it's not because there is air in the system.
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Progress on the 1967 bug brakes
I replaced the left rear rear wheel cylinder and was able to bleed the brakes. When I took off the drum both of the springs were laying in the drum and the retaining pins were still there. But the spring plates were mangled bits of metal. I stole parts from my other vw but they wouldn't stay in place. I ended up putting it back together without the springs and pins.
I also found the drum is bent or warped. I could see that as I spun the drum. Either the drum or the axle is warped. Replacing the drum is no big deal but I think replacing the axle would be a big deal. Anyone know which is more likely, a damaged drum or axle?
TIA,
Kevin
I also found the drum is bent or warped. I could see that as I spun the drum. Either the drum or the axle is warped. Replacing the drum is no big deal but I think replacing the axle would be a big deal. Anyone know which is more likely, a damaged drum or axle?
TIA,
Kevin
- Marc
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You've got to have the pins ("nails") and retainers installed for the brakes to work & wear properly. If you can't find some "proper" VW parts, take the nails and springs to your FLAP store and see if they can fix you up with some retainers that'll work
Replacing a bent axle on a swingaxle car is a biggy - not so much if it's IRS. With the drum removed, place a jackstand so it's right next to the axle splines and run the engine (chock the other wheels for safety), looking at the gap between axle and jackstand for any wobble. If it looks OK, repeat with the drum installed but the axle nut only hand-tight. If the "nose" of the drum runs true but the outer rim has run-out, a new drum is in order. Still OK? Torque down the axle nut (~250 lb-ft) - if that's the only time you see wobble, you've got a bad spacer that's worn/crushed unevenly and causing the axle to deflect when the nut's tightened...that's the best news you can hope for, changing the spacer is trivial.
Replacing a bent axle on a swingaxle car is a biggy - not so much if it's IRS. With the drum removed, place a jackstand so it's right next to the axle splines and run the engine (chock the other wheels for safety), looking at the gap between axle and jackstand for any wobble. If it looks OK, repeat with the drum installed but the axle nut only hand-tight. If the "nose" of the drum runs true but the outer rim has run-out, a new drum is in order. Still OK? Torque down the axle nut (~250 lb-ft) - if that's the only time you see wobble, you've got a bad spacer that's worn/crushed unevenly and causing the axle to deflect when the nut's tightened...that's the best news you can hope for, changing the spacer is trivial.
- Marc
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http://www.1800vw.bizhosting.com/images/SAPartsPage.jpg
Inner spacer (under the bearing) is #12. 111 501 281A
Outer spacer is #17. 111 501 303A
Inner spacer (under the bearing) is #12. 111 501 281A
Outer spacer is #17. 111 501 303A
- Marc
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How so? I've got a compressed-air-powered eduction bleeder like this one: http://www.harborfreight.com/cpi/ctaf/d ... mber=92924 and I love it.
A proper pressure bleeder is designed like an accumulator with a diaphragm separating the fluid from the air pressure. Merely air-loading the reservoir as Zen suggests doing will tend to aerate the fluid - it'll work, but should be followed up by a conventional "foot" bleed the next day.
A proper pressure bleeder is designed like an accumulator with a diaphragm separating the fluid from the air pressure. Merely air-loading the reservoir as Zen suggests doing will tend to aerate the fluid - it'll work, but should be followed up by a conventional "foot" bleed the next day.
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We have a vacuum (compressed air operated, much like in Marc's link) bleeder at work, it is used only for flushing the system, i.e. getting the fluid out. Actual bleeding is always done by gravity or if that doesn't work, pumping (2 people).
I hate vacuum bleeders, by design they cannot work properly. The brake system seals are designed to seal under pressure only. Under vacuum, they let air in.
It is almost free to make a pressure bleeder tool out of an old beetle windshield washer bottle. Everything is there, the pressure valve, airtight cap, and the outlet hose. All you need is a plastic coke bottle cap to push the outlet hose through, and use that instead of the original VW reservoir cap... very small pressure is needed, and then you can crack all the bleeders open and let it bleed. You have at least a quart of fluid in the washer reservoir. Nothing but fluid will come out, so you could also reverse bleed the system: Hook the pressure bleeder to each wheel bleeder valve and push new fluid upstream towards the master reservoir. Sometimes I have used that as a last resort too with success
I hate vacuum bleeders, by design they cannot work properly. The brake system seals are designed to seal under pressure only. Under vacuum, they let air in.
It is almost free to make a pressure bleeder tool out of an old beetle windshield washer bottle. Everything is there, the pressure valve, airtight cap, and the outlet hose. All you need is a plastic coke bottle cap to push the outlet hose through, and use that instead of the original VW reservoir cap... very small pressure is needed, and then you can crack all the bleeders open and let it bleed. You have at least a quart of fluid in the washer reservoir. Nothing but fluid will come out, so you could also reverse bleed the system: Hook the pressure bleeder to each wheel bleeder valve and push new fluid upstream towards the master reservoir. Sometimes I have used that as a last resort too with success