Air suspension - leak?

[MtnManCA]

Hello,

The front forks of my 1982 GS 1100GK don’t maintain their air pressure. Within seconds the pressure drops to a level that cannot be measured anymore.

I replaced the fork seals and the air.valves. The fork seals don’t leak oil. Could they leak air but not oil?

[Rob S.]

First off, 99% of members will tell you to ditch the air system. Just buy new springs (straight rate) because the originals might still be on. Determine the rate using Race Tech's charts.

If you must have your air, remember it requires a special purpose made pump to charge it. You can't use a standard 'tire filler' hose. You'd pop the air seals in 3/5 of a second.

[phydeauxmutt]

Rob pretty much nailed it, except for the time to pop the seals. Only the very best seals will wait a full 3/5 second to pop.

Sonic Springs are highly-recommended by most here (including me). Depending on your personal 'gravitational attraction', I would suggest either the 1.1 or 1.2 rate springs.

[Grimly]

Seconded and thirded to all above.
I had a go at re-instating air suspension to the forks, but it was a long hard frustrating job and I finally gave up with it. While it worked, it was great, but it wouldn't hold pressure for more than a day. I ended up finagling a manual pre-loader on the top of each fork cap and never touched them since.

[Gorminrider]

I'd think,if only ideally, fork seals shouldn't leak air whether air-adjustable or not. The air-space above the oil level is ideally a component of the suspension.

I've used adjustable- air-forks carefully on a couple of bikes with middling success. You can't get them to correct pressure without a special low pressure gauge and a small bicycle pump....And, where Honda links the forks with a tube so they are equal, Suzuki does not, which is a nuisance. Especially if one seal leaks faster than the other!

You can 'equalize them to "atmosphere" pressure without a gauge and pump. Lift the front wheel off the ground and open the air valves or crack the fork caps.

Aftermarket seals might be the problem. (added)Or, obviously(!)the chrome surface of the forks

[Rob S.]

Honda links the forks with a tube so they are equal, Suzuki does not...

There is a tube running between the forks of my 11E.

[phydeauxmutt]

... And, where Honda links the forks with a tube so they are equal, Suzuki does not, which is a nuisance. ...

There is a tube running between the forks of my 11E.

Not sure if the 750 of the same era did that, but I have only seen a balance tube on the chain-driven 1100s.

[Gorminrider]

Huh! I see you are right about the 1100 (I happen to have the manual)...I always meant to add one to my 650 but this one looks complicated...

[salty_monk]

The forks have a little hole & there are special collars when you have that balance tube..... Above advice is definitely the way to go. Add cartridge emulators is you want to go a level further in refinement