Leaking Bleeder Valve on A Caliper

[Roger 911]

Man this is frustrating. I just installed a set of totally rebuilt (by a Porsche shop) A calipers, including new OE bleeder valves. They looked absolutely fantastic. Unfortunately, one of the valves is leaking from the threads. I searched this forum and found a couple posts about this, with suggestions ranging from clean the threads to send back the caliper. I'm certain the threads were clean and I have a DE next weekend, so I do not have time to send these back and forth to the shop.

Does anyone have any other suggestions? What about Teflon tape? Will that withstand the high heat of track use?

Any help is appreciated. Thanks.

Roger

[86 911 Targa]

Originally Posted by Roger 911

Man this is frustrating. I just installed a set of totally rebuilt (by a Porsche shop) A calipers, including new OE bleeder valves. They looked absolutely fantastic. Unfortunately, one of the valves is leaking from the threads. I searched this forum and found a couple posts about this, with suggestions ranging from clean the threads to send back the caliper. I'm certain the threads were clean and I have a DE next weekend, so I do not have time to send these back and forth to the shop.

Does anyone have any other suggestions? What about Teflon tape? Will that withstand the high heat of track use?

Any help is appreciated. Thanks.

Roger

Roger,

Have you checked for X-threading?

Is there a machine shop nearby?

You could try running a tap very gently through the threads.

Teflon tape might work, but other members will chime in with some other ideas.

Good luck,

Gerry

[Roger 911]

Yes, I just pulled the valve out again and the threads look great. The valve even appears to have a uniform band (where the gold finish has rubbed off) around the tapered part that would imply it is making contact with the seat all around.

[86 911 Targa]

Originally Posted by Roger 911

Yes, I just pulled the valve out again and the threads look great. The valve even appears to have a uniform band (where the gold finish has rubbed off) around the tapered part that would imply it is making contact with the seat all around.

Roger,

Do you have, or can you get another bleeder valve?

And, did you have this issue prior to the re-work?

Gerry

[86 911 Targa]

Originally Posted by Roger 911

Yes, I just pulled the valve out again and the threads look great. The valve even appears to have a uniform band (where the gold finish has rubbed off) around the tapered part that would imply it is making contact with the seat all around.

Roger,

Here's another thought.

Try transposing the valve with another one on your car that is not leaking.

If the leak persists with the transposed valve, the issue is the caliper.

If not, it's the valve.

Good luck,

Gerry

[Roger 911]

I could probably get another bleeder. The calipers are new to me, so I don't have any previous knowledge on how they worked before the rebuild.

Update: When I put the valve back in 20 min ago, I had my son do the "pedal pump" while I opened and closed the valve. It's too early to say for sure, but it does not appear to be leaking as before. Granted, it's only been 20 minutes, but previously, I would have already started to see a little blue fluid starting to accumulate at the base of the threads. Maybe I just needed to "bed" the valve by opening and closing a few times?

[86 911 Targa]

Originally Posted by Roger 911

I could probably get another bleeder. The calipers are new to me, so I don't have any previous knowledge on how they worked before the rebuild.

Update: When I put the valve back in 20 min ago, I had my son do the "pedal pump" while I opened and closed the valve. It's too early to say for sure, but it does not appear to be leaking as before. Granted, it's only been 20 minutes, but previously, I would have already started to see a little blue fluid starting to accumulate at the base of the threads. Maybe I just needed to "bed" the valve by opening and closing a few times?

Roger,

If this helps,

My Bentley shows 3Nm (27 in-lb) torque on the valves for a non-Turbo.

Good luck,

Gerry

[Gogar]

Is the bleeder valve new from the rebuild? If not, I think that may be a cheap way to start. Also, swapping the bleeder valves from l/r calipers would be a good way to see if the leak follows the bleeder, as mentioned.

[Roger 911]

Yes, the bleeder valve is new. I think I'll keep my fingers crossed and hopethat I "bedded" it in.

[tabasco]

I doubt the threads really seal anything.
I think they work like a compression fitting, the cone at the end cone does all the sealing, so that's where you should look.
If you have some shavings down there, or if they are not bedded in they will leak.

-Guillaume

[kidrock]

probably flogging a dead horse here, but did you save an old bleeder valve? tabasco might be on to something here.

[Roger 911]

Originally Posted by tabasco

I doubt the threads really seal anything.
I think they work like a compression fitting, the cone at the end cone does all the sealing, so that's where you should look.
If you have some shavings down there, or if they are not bedded in they will leak.

-Guillaume

You're right about the threads. That occurred to me when I took the valve out, i.e., the threads are after the little hole. I think it is the "bedding" issue. I'll check them closely this weekend while at the track. A few traditional bleeds may solve the problem.

Thanks.
Roger