Wheezing upper fork?

[jjwithers]

I'm kinda going crazy on this one...
the bike is a R75/5.
I have a san jose upper fork brace.
Front end is assembled. When i hold the front brake and push down on the forks, the left fork 'wheezes' a bit... in other words, i hear air passing through the top of the fork somewhere.
I have tried a few upper funnel shaped fork nuts. they all do the same thing. And yes, they are tight.
The upper fork cap has been through a new crush ring-washer, and it is tight.

Any ideas where or how air would be leaking out? Is this common?
I am thinking of adding plumbers tape to the upper fork nut.

[ME 109]

Has the bike ever smoked before?

Seriously, try some soapy water to firstly identify where the leak is, and indeed, if the leak is to atmosphere or contained within the fork.

[wookie]

If you have fork gaiters, look for the small tubes in the bottom of the lower triple clamp close to the steering stem.

They are there to vent air from the gaiters when the fork compresses. That could be your source assuming you are wrong about the location of the "wheezing".

[jjwithers]

No gaiters.
And the top of the fork tube is making solid contact with the san jose upper triple tree.
I'll try the soap...
but something is 'breathing' when i compress the forks and they decompress. only on one side.

[Major Softie]

I've never had a fork do that with air escaping from the fork, but I've had them do it all inside the fork. It was decades ago, so I don't remember what was wrong, but something had been assembled incorrectly.

[jjwithers]

I can't imagine what would be at the top of the fork that isn't assembled correctly. It is just screwed in parts. There really isn't much to it and i can't see how air could escape unless the threads are faulty...

I've never had a fork do that with air escaping from the fork, but I've had them do it all inside the fork. It was decades ago, so I don't remember what was wrong, but something had been assembled incorrectly.

[Major Softie]

I can't imagine what would be at the top of the fork that isn't assembled correctly. It is just screwed in parts. There really isn't much to it and i can't see how air could escape unless the threads are faulty...

I've never had a fork do that with air escaping from the fork, but I've had them do it all inside the fork. It was decades ago, so I don't remember what was wrong, but something had been assembled incorrectly.

You misunderstood. Not air escaping (in my case), but the same sound from something happening only within the fork.