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Using power bleeder

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Old 05-08-2007, 08:05 PM
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StratfordShark
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Originally Posted by Hacker-Pschorr
I just had what an alcoholic would call a moment of clarity. My power bleeder was leaking around the cap to the bleeder (with no fluid squirting out). I ended up taking the gromet out of the reservoir cap and installing it into the cap of the bleeder. Worked like a charm.
Nice idea H-P but I've just tested the power bleeder by plugging the line at the reservoir cap and it holds pressure fine.

My leak is somewhere in the reservoir/MC/booster area but fluid level is fine so I don't think I'm losing fluid from the MC back into the booster. Too dark now but first thing tomorrow I'll put some soapy solution on the MC bleeder and see if that's the problem.

Wondering if meantime I can still use the power bleeder by having someone (my wife can be very understanding) keep it pumped up while I open and close the bleeders? Will experiment tomorrow to see how hard you have to pump to maintain it at say 10psi.

Thanks for all your suggestions.
Old 05-08-2007, 08:11 PM
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Originally Posted by StratfordShark
Nice idea H-P but I've just tested the power bleeder by plugging the line at the reservoir cap and it holds pressure fine.
I might be missing something - I'm talking about how the cap seals to the reservoir opening.
Old 05-08-2007, 08:18 PM
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Originally Posted by Hacker-Pschorr
I might be missing something - I'm talking about how the cap seals to the reservoir opening.
Sorry I thought you meant you had a leak at the top of the bleeder bottle!

Will take a look at the original reservoir cap tomorrow and see if the grommet pops out easily. Would be great if that's where I'm losing pressure but there is that ominous hissing noise which I'm sure is from vicinity of the MC. If an MC seal has gone bad, would that show up as a pressure loss? I think I read another post here saying the pressure is same on both sides of the seal when you use a pressure bleeder.
Old 05-08-2007, 08:19 PM
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Originally Posted by Hacker-Pschorr
I might be missing something - I'm talking about how the cap seals to the reservoir opening.
Sorry I thought you meant you had a leak at the top of the bleeder bottle so I just wanted to check integrity of the power bleeder itself!

Will take a look at the original reservoir cap tomorrow and see if the grommet pops out easily. Would be great if that's where I'm losing pressure but there is that ominous hissing noise which I'm sure is from vicinity of the MC. If an MC seal has gone bad, would that show up as a pressure loss? I think I read another post here saying the pressure is same on both sides of the seal when you use a pressure bleeder.
Old 05-09-2007, 10:01 AM
  #20  
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Originally Posted by Hacker-Pschorr
I might be missing something - I'm talking about how the cap seals to the reservoir opening.
You cracked it H-P!

Went to check power bleeder cap this morning - no gasket. Wait a minute, at the bottom of the box is a short tube for collecting fluid at the bleeder, and that rubber ring round it which I had assumed was just a kind of clip to secure the tube on the nipple turns out to be the gasket that should have been in the cap!

Popped it in, pumped up, no leaks!

Just waiting for rain to stop so I can do the bleed now.

Many thanks for pointing me in right direction. I don't think it would ever have occurred to me without your suggestion Hacker-Pschorr.
Old 05-09-2007, 11:12 AM
  #21  
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Did a power bleed on my 89 S4 this weekend. Instructions said no more than 20psi, so I went to 15. No leakage, hissing, etc..

Did off-side rear first, then sequence to fronts. Tipped the bottle on it's side when done, MC sought it's own level, i.e. no overfill. S L O W L Y opened the bottle, depressurized & dumped the excess fluid (took about 10-12oz).

When I first opened the bleeder valves, fluid looked like coca cola. I let it run until nice and clear. Now have a much better pedal - high & hard.

BTW, to simplify the process take an empty, clear 12oz plastic drink container & drill a 1/4" hole in the cap. Place a few old bolts or small rocks in the bottle for weight/stability. Then take approx. 2 feet of 1/4" silicone tubing (surgical supply house has it or try usplastic.com) and fit through the hole you just drilled, to an inch off the bottom. Now take another 2 feet of soft wire and wrap one end around the bottle neck, bend it up and place the other end in the open side of the tubing to hold it up/vertical. this keeps it from dragging on the ground and the wire can be bent around any portion of the caliper/wheel stud/backing plate to keep the bottle in place.

The silicone tubing stretches over the bleed nipple nicely, no leakage. Clear bottle lets you see the fluid color & any bubbles. Wire keeps everything in place. When you are done, just pinch the tubing, tighten the bleed valve, and pull the tubing off, hold it vertical to drain any excess into the bottle & place the wire back into it. Voila! No drips, no leaks, no messy brake fluid on the floor.

Have fun.

Hawkeyes
Old 05-09-2007, 01:17 PM
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Originally Posted by Hawkeyes
Did a power bleed on my 89 S4 this weekend. Instructions said no more than 20psi, so I went to 15. No leakage, hissing, etc..

Did off-side rear first, then sequence to fronts. Tipped the bottle on it's side when done, MC sought it's own level, i.e. no overfill. S L O W L Y opened the bottle, depressurized & dumped the excess fluid (took about 10-12oz).

When I first opened the bleeder valves, fluid looked like coca cola. I let it run until nice and clear. Now have a much better pedal - high & hard.

BTW, to simplify the process take an empty, clear 12oz plastic drink container & drill a 1/4" hole in the cap. Place a few old bolts or small rocks in the bottle for weight/stability. Then take approx. 2 feet of 1/4" silicone tubing (surgical supply house has it or try usplastic.com) and fit through the hole you just drilled, to an inch off the bottom. Now take another 2 feet of soft wire and wrap one end around the bottle neck, bend it up and place the other end in the open side of the tubing to hold it up/vertical. this keeps it from dragging on the ground and the wire can be bent around any portion of the caliper/wheel stud/backing plate to keep the bottle in place.

The silicone tubing stretches over the bleed nipple nicely, no leakage. Clear bottle lets you see the fluid color & any bubbles. Wire keeps everything in place. When you are done, just pinch the tubing, tighten the bleed valve, and pull the tubing off, hold it vertical to drain any excess into the bottle & place the wire back into it. Voila! No drips, no leaks, no messy brake fluid on the floor.

Have fun.

Hawkeyes
Now I've put in the gasket in the lid I get no leaks or hisses either. Was mistaken or just pessimistic when I thought the hiss was from the MC.

Nice tip on the collecting bottle Hawkeyes - thanks.

When you tipped the bleeder bottle on its side when you were done did you also open a bleeder to let air back into the MC or was the level just OK by itself?

Thanks,

Adrian
Old 05-09-2007, 01:18 PM
  #23  
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Great idea on the drink bottle!

Carrying that a step further, keep a spare cap handy and you can seal and dispose of the old fluid right in the drink bottle. Make sure it doesn't look like diet pepsi in there though!
Old 05-10-2007, 07:23 PM
  #24  
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Originally Posted by StratfordShark
Now I've put in the gasket in the lid I get no leaks or hisses either. Was mistaken or just pessimistic when I thought the hiss was from the MC.

Nice tip on the collecting bottle Hawkeyes - thanks.

When you tipped the bleeder bottle on its side when you were done did you also open a bleeder to let air back into the MC or was the level just OK by itself?

Thanks,

Adrian
Yes, I opened the closest (LF in U.S.) bleeder valve in order for MC to reach level. Sorry for the omission.

Hawkeyes



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