Problem filling forks with air

[Mr. Jiggles]

I've got an '82 GS1100e with air forks, the type that fills via a single shrader (sp?) valve located on the side of the left fork by the lower triple tree clamp. I've tried filling it with air using a hand-help compressor but it won't take air. There's no pressure in the forks since I recently changed the fork oil. Are there any tricks to pressurizing the forks that the manual isn't mentioning??

Thanks,

Jeff

[Billy Ricks]

Check the positioning of the yolk that fits around the fork between the upper and lower triples that the valve is on.

[Anonymous]

Your lower trees (I think) have o-ring seals for the air. If they are bad, then you won't hold.

[Anonymous]

If it won't take air (as opposed to not hold air), are you loosening the two plugs on the front side of the lower triple tree clamps?
If you are, I think I'd remove the schader valve and make sure that you can pump air through it when not installed.

[Mr. Jiggles]

Thanks for all the replies.

That's correct it won't take air - Once I get the forks pressurized I'll know if it will actually hold air. I haven't yet tried loosening the two plugs on the front of the triple tree clamps. Unfortunately my manual does not give a detailed diagram of how air gets into these forks and the steps necessary to fill them. I'll give that a try.

Thanks,

Jeff

[Anonymous]

I haven't yet tried loosening the two plugs on the front of the triple tree clamps.

That's the probably problem then. Those plugs (called air stop valves in the factory manual) block the air once you get it to the pressure you want. Just in case your manual doesn't give you the pressure to run at it's 7 psi.

[Dink]

Or even better still set the sag up correctly with spacers and forget about air altogether as all it does is aerate your fork oil and reduce the effectiveness of the forks.
Sag should be set at approx. 25-30mm, and is measured as the difference between two points unloaded compared to loaded; i.e. the lower triple clamp and the seal cap. BTW this also applies at the rear.
Dink

[Mr. Jiggles]

GSR to the rescue once again. Thanks for all of your replies, guys. As it turns out it was just those two plugs. My Haynes manual doesn't mention a word about how to pressurize the fork tubes other than saying to "remove air valve dust cap" and to pressurize both forks equally if you don't have a cross-over tube.

I'll try the forks at 7psi (Haynes suggests a range of 7-35psi). If not to my liking then I'll give the spacers a try.

Thanks again,

Jeff

[Anonymous]

It sounds like I was wise to buy Clymer! The procedure is well documented there. They caution not to overtighten those plug bolts.

You can use those bolts to determine if one or both legs is not holding air: Block up the front end so there is no weight on the front wheel. Open both bolts and pump the forks up to about 20/25 psi, then bleed down to the recommended psi (7.8 for the '81). Close both bolts and reinstall the cover on the schrader valve. Some time later, open only the near side bolt, then check the psi. Then, open the far side bolt, TOO, then check the psi again. If there is a marked difference in pressure between the two checks, one (or both) leg(s) is leaking. If the first reading was significantly lower than when filled, the leg nearest the schrader is leaking. If the second reading is significantly lower, the far leg is leaking.

All of this is made much easier if you own a Progressive Suspension or similar small volume pump/guage with the double o-ring sealed connector.

[Anonymous]

GSR to the rescue once again. Thanks for all of your replies, guys. As it turns out it was just those two plugs. My Haynes manual doesn't mention a word about how to pressurize the fork tubes other than saying to "remove air valve dust cap" and to pressurize both forks equally if you don't have a cross-over tube.

I'll try the forks at 7psi (Haynes suggests a range of 7-35psi). If not to my liking then I'll give the spacers a try.

Thanks again,

Jeff

That 35 psi is maximum pressure you should put in the fork, NOT one you should actually use in operation.
I don't know why they even mention it in the manuals, it just confuses people. And has probaby caused a number of problems.
Anyway I "think" the max operational pressue on the forks is 11 psi but I'd have to check my manual to be sure.