I spent another 1-2 hours tonight bleeding the brakes on my 914. The rears bled fine but one of the fronts (which I rebuilt) is giving me what seems like an endless stream of tiny bubbles. I haven't checked the other front yet but I am guessing it will too.

How long is this supposed to take?? Is bleeding brakes a day long job after you rebuild the calipers and put them on dry?

I've been through over 2 quarts of brake fluid so far. I think just on this one caliper we pumped it about 100 times! Tiny little bubbles forever and ever.

Also I noticed that the assembly lube I used is dissolving into the brake fluid, I get some blue bubbles from time to time as well. That doesn't seem right. I used the Permatex stuff in the little packets that says you can use it on caliper pistons etc etc.

Anyone have a pressure bleeder I can borrow?

QUOTE

Anyone have a pressure bleeder I can borrow?

When do you want to pick it up???

I "might" be going to Belmont tommorow...on Friday I am going to SJ around lunch time to do some welding on Bowlsbys 914 (I hope it's the LE, I've always wanted to do something destructive to one of those, welder or sawzall, I'll be happy, LOL)

of course you know where I work, so you could always pick it up.....

You doing it by yourself? Either get a helper or some speed bleeders....if you keep getting air in one line...."I" would look for a leak up stream.

Have you considered replacing the rubber lines and looked for leaks in the steel line?

Jeff, if you need help let me know. I've never bled brakes except for stepping on the pedal for B while he bled them. But if that would help, I'm just down the street from you!

Jen

Once you get a hold of a pressure bleeder, you may want to consider putting in the brake fluid through the caliper nipple. Just do it slowly so it doesn't overflow the resevoir. This tends to push all the air bubbles out.

This is a trick that I did on my motorcycle after I rebuilt the caliper and put on new brake lines. I imagine this should work for the 914 as well.

Look luck and let me know if you try this and if it works for you.

I have a pressure bleeder as well you can borrow if you don't like Mike's.

QUOTE

but one of the fronts is giving me what seems like an endless stream of tiny bubbles.

This may be air that is drawn in around the threads on the bleeder. Try loosening the bleeder just enough to force fluid thru it or use some thick grease to seal around it. Speed bleeders usually have some sealing compound on the threads to prevent this.

Get a spare cap for the brake fluid resevior.
Get a tire valve & stem.
Drill a hole in the center of the resevior cap, the same size as the hole in a wheel (or measure the narrow part of the tire valve).
Pull the valve stem through the hole.
Remove the plastic screen in the resevior.
Fill the brake resevior completely, not to the fill line, all the way full to the bottom of the tube that holds the plastic screen.
Put on your new modified pressure bleeder cap.
Drain your air tank to 10 psi, for cheaper compressors setting the regulator at 10 psi may not work. If you put too much pressure in the system, you'll blow off the blue lines that connect the supply lines to the resevior, or worse.
Take a clip on air chuck and clip it on your new pressure bleeder cap.
Bleed the brakes, starting at the furthest bleeder from the master cyl, and finish at the bleeder nearest the master cyl.
Pump the pedal hard about ten times and repeat the proceedure.
Do not get brake fluid on painted surfaces it will ruin them.
If the pressure bleeder cap retains pressure, bleed it down before taking it off the resevior.
This works very well, and makes it a one person job.
Replace brake fluid every two years.
Properly discard used brake fluid.

Hey Jeff,

I brought the pressure bleeder to work today.....I'm working late so I'll be around here until about 10pm or so.....

do you have a good timing light? mine is acting goofy on my and I'm not sure if it's the light or my car electrical acting up

9146: My air compressor spits a lot of water with the air. I would need at least one dryer to get the air supply dry enough to even THINK about getting near brake fluid. It's a good idea but my compressor may not be suitable.

ejm - Good point about the bleeders leaking air. I thought about that. Maybe I could put some PTFE thread sealant on the bleeder threads, or would that contaminate the brake fluid??

Z - I will check for air leaks and tighten some connections. Is it possible for the master cyl to draw in air around the grommets that the lines from the res pass thru?

kermit - I will try that trick if I get a pressure bleeder. Interesting idea!

Mark, Mueller - thanks for the offers, who will be closest to Sunnyvale in the near future? I am practically living at work these days.

Jenny - When my (so far very understanding) roommates get tired of helping I will recruit you. Thanks.

QUOTE (Mueller @ Mar 30 2005, 12:00 PM)

Hey Jeff, I brought the pressure bleeder to work today.....I'm working late so I'll be around here until about 10pm or so..... do you have a good timing light? mine is acting goofy on my and I'm not sure if it's the light or my car electrical acting up

Mike, PM me your #. I will probably be working past midnight tonight but if I can get off early I will take a trip over this evening. Thanks.

I own a timing light, but my brother is borrowing it already. Sorry!!

Hey, Mike! My timing light is in Milpitas, near the Double Secret Former Number Four Hide-Out Spot. I can probably be convinced to drop it by your work. (Got any food? )

Oh, right. The phone. That works, too, doesn't it?

--DD

QUOTE (Dave_Darling @ Mar 30 2005, 02:11 PM)

Hey, Mike! My timing light is in Milpitas, near the Double Secret Former Number Four Hide-Out Spot. I can probably be convinced to drop it by your work. (Got any food? ) Oh, right. The phone. That works, too, doesn't it? --DD

that'll work, I can buy you a meal

QUOTE

This may be air that is drawn in around the threads on the bleeder.

word up!

you can rap the caliper with a hammer a few time to to assure you dislodge any clingy bubbles

QUOTE (Mueller @ Mar 30 2005, 01:14 PM)

that'll work, I can buy you a meal

Sorry about that--I couldn't find the main part of the light....

--DD

QUOTE (Dave_Darling @ Mar 30 2005, 08:03 PM)

QUOTE (Mueller @ Mar 30 2005, 01:14 PM) that'll work, I can buy you a meal Sorry about that--I couldn't find the main part of the light.... --DD

no big deal...I'm sure I'll find someone else locally that has one

I have seen two different designs of speed type bleeders. The Speedbleeders brand has a check valve contained withing the bleeder body. The second type I've seen, has a ball check that extends past (below) the bleeder body and seats against the caliper. Though I have not used either one, it seems to me that the latter is the better solution, since there is no chance for air to suck back into the system around the threads. Anyone?

Andy

It could be your master cylinder. The last time I spent a lot of time trying to bleed brakes it was the mc that caused the trouble. This was after I rebuilt all the calipers and replaced all the lines and double checked everything. I was still getting air in the lines. Replaced the mc. Problem solved. Speedbleeders work great.
Cheers, Elliot

i use a gatorade bottle with a hose ,leave 1/3 bottle full of fluig. i have done at least 200 cars that way no problems, there can be other problems, you need to be able to recongnize

[QUOTE]i use a gatorade bottle with a hose ,leave 1/3 bottle full of fluig. i have done at least 200 cars that way no problems, there can be other problems, you need to be able to recongnize

I have done this too and it works. Keep the end of the bleed tubing immersed in fluid and slowly pump the brake pedal while leaving the bleeder cracked open.
DH