air shocks deflated???

[madmax-im]

not sure wtf is going on...but I'm riding along and I am noticing that the rear shocks are bottoming out over rough bumps and banging the frame...I havent added any air since we installed the airshocks several months ago...is it normal for this to happen over time or are they supposed to hold their air pressure much longer than 2 months...I guess I shouldnt assume that once set to the pressure i want that it will stay that way without some regular checking and such...We did replace all the internal seals in the shocks but yet theu still leaked out their air...

[jetmechmarty]

Are these 30+ year old air shocks? I seem to recall you're running Maxim shocks, right. Have they been rebuilt? It's likely that time. They should hold air indefinitely.

[Prothec]

I don't check them very often, but they don't seem to have lost a noticeable amount of air/oil over the past 4 months or so.

I have replaced the seals on my XJ shocks twice before they stopped leaking air and oil. I had a decent amount of pitting on the inner tube surface. The second time around I filed/sanded/polished as much of the pitting out as I possibly could and it seems to have done the trick.

[3Phase]

Can you put the shocks in a bucket of water?

If that's too much fun, pour some soapy water over the crossover line and the fittings.

It's less likely than loose fittings or bad shock seals but the rubber air line might have cracked or split if the seat pan got tightened down on it.

The steel fittings can work loose and/or strip the aluminum upper shock body. If you rebuilt them you know they use small o-rings instead of compression to seal the crossover line, ke bareful.

The local hydro-pneumatic shop probably won't have the Japanese/British Imperial threaded fittings in stock and you'll have to make a new crossover line and drill/tap the shock body for the new fittings. If it actually does come down to that point it'd be cheaper and easier to just get another pair of used shocks on eBay and keep the old ones for parts.

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[madmax-im]

Are these 30+ year old air shocks? I seem to recall you're running Maxim shocks, right. Have they been rebuilt? It's likely that time. They should hold air indefinitely.

Mark and I rebuilt them...new seals...the other day there was a small blotch of fork oil on the rear tire...coming from the right side shock......guess we're gonna have to pull them off and have and recheck every thing..

[madmax-im]

Can you put the shocks in a bucket of water?

If that's too much fun, pour some soapy water over the crossover line and the fittings.

It's less likely than loose fittings or bad shock seals but the rubber air line might have cracked or split if the seat pan got tightened down on it.

The steel fittings can work loose and/or strip the aluminum upper shock body. If you rebuilt them you know they use small o-rings instead of compression to seal the crossover line, ke bareful.

The local hydro-pneumatic shop probably won't have the Japanese/British Imperial threaded fittings in stock and you'll have to make a new crossover line and drill/tap the shock body for the new fittings. If it actually does come down to that point it'd be cheaper and easier to just get another pair of used shocks on eBay and keep the old ones for parts.

.

will try the soapy water trick need to check the crossover line too...at the time of installation everything was good. We were able to tye the crossover loosely so that the seat would not crimp it...

[bikerphil]

Ahhh, the joys of having air assisted suspension.

[3Phase]

Ahhh, the joys of having air assisted suspension.

Do nitrogen-filled fork and shock absorber cartridges and emulators use some kind of special non-atmospheric air assisted nitrogen or what?

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[bikerphil]

Do nitrogen-filled fork and shock absorber cartridges and emulators use some kind of special non-atmospheric air assisted nitrogen or what?

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Yes they do. Good units have the nitrogen contained and shouldn't need constant monitoring/adjustment.

[3Phase]

Hint: air on Earth is ~78% nitrogen

Yes they do. Good units have the nitrogen contained and shouldn't need constant monitoring/adjustment.

And when they are not good little units and they leak, where does the nitrogen come from to refill them after they are repaired or replaced? Air?

.

[bikerphil]

Lol, yep I got that, 3/4 nitrogen blend is just fine by me. Don't get me wrong, the XJ air shocks are fine units. Hopefully, most of them don't leak, it sucks when you start riding and then have to stop to add air. BTDT with air assist forks/shocks, never again.

[madmax-im]

Lol, yep I got that, 3/4 nitrogen blend is just fine by me. Don't get me wrong, the XJ air shocks are fine units. Hopefully, most of them don't leak, it sucks when you start riding and then have to stop to add air. BTDT with air assist forks/shocks, never again.

in 30 years owning the Maxim I only once had a problem with my airshocks and that was back in 2009 at the XS East rally in VT.

[3Phase]

Lol, yep I got that, 3/4 nitrogen blend is just fine by me.

Whew! Thank goodness! The price of extraterrestrial nitrogen has gone sky high ever since NASA retired the Shuttle and the Soviet Soyuz missions have been misfiring.

Don't get me wrong, the XJ air shocks are fine units. Hopefully, most of them don't leak, it sucks when you start riding and then have to stop to add air. BTDT with air assist forks/shocks, never again.

I try not to ride hard enough on the street to need or notice the difference in weight and performance between regular air suspension and high pressure gas suspension. I don't trust old frames.

I like nitrogen as a general concept in suspension gasses because it keeps the oil in the shocks/forks from oxidizing and it can cut down on oil foaming. The high pressure cartridges are nice because they're smaller so they have less mass and they can do the same amount of work as a larger, traditional air suspension component but then you have the usual problem associated with high pressure gasses and moving parts: cost and long-term reliability. I haven't seen many thirty-year-old cartridge suspension parts for sale that still work and can hold their nitrogen. You're definitely not going to refill one out on the road with a small electric or hand pump.


I'd still like to put cartridges on my bike though!

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[MaximPhil]

in 30 years owning the Maxim I only once had a problem with my airshocks and that was back in 2009 at the XS East rally in VT.

Hi Ben,
I recall the exhaust FALLING OFF on that rally.
"Does my bike sound loud to you" was the quote of the day
Fun times.
Phil

[bikerphil]

in 30 years owning the Maxim I only once had a problem with my airshocks and that was back in 2009 at the XS East rally in VT.

Well Ben, I hope you get yours straightened out and do not have any more problems. Just remember to run about 77% nitrogen in them after fixing the leak.