Should I be worried? Air bag pressure going down between rides?

[Bartender]

Should I be worried. 2019 RTL with air bag. It has always held air without any problems. I never hear the on board air compressor run. Must be my hearing. Last Sunday, I checked air in the air bag before leaving on a 2 hour ride and it checked at 25 lbs. Rode two hours and on my return it checked at 43 lbs which is where it usually had been. Checked last night and it as back to 25 lbs. Is this a sign of a leaky air bag or just the season of the year and fluctuating air pressure due to changes in the outside temperature? Since I can't hear the air compressor I don't know if it's constantly running.

 

[BLUEKNIGHT911]

Should I be worried. 2019 RTL with air bag. It has always held air without any problems. I never hear the on board air compressor run. Must be my hearing. Last Sunday, I checked air in the air bag before leaving on a 2 hour ride and it checked at 25 lbs. Rode two hours and on my return it checked at 43 lbs which is where it usually had been. Checked last night and it as back to 25 lbs. Is this a sign of a leaky air bag or just the season of the year and fluctuating air pressure due to changes in the outside temperature? Since I can't hear the air compressor I don't know if it's constantly running.

Well it is possible ( I think ) that 25lbs is the default setting. So when you arn't on it and applying some weight it reverts back. .... While the engine is running, have a passenger get on then you get on. .... everyone get off and then check it to see what you have .... good luck .... Mike :thumbup:

 

[IdahoMtnSpyder]

I say it's leaking. Check the fittings on the air line. More likely leaks are the check valve, the schrader valve, or a pebble has worn a hole in the bottom of the bag.

 

[BLUEKNIGHT911]

I say it's leaking. Check the fittings on the air line. More likely leaks are the check valve, the schrader valve, or a pebble has worn a hole in the bottom of the bag.

" LEAKING " ..... and it is stopping at 25lbs. ... why would it STOP at 25lbs. ????? .... Mike :thumbup:

 

[Peter Aawen]

" LEAKING " ..... and it is stopping at 25lbs. ... why would it STOP at 25lbs. ????? .... Mike :thumbup:

On pretty much anything else, that leak down then stop at a pressure like 25 psi might be unlikely, but in this case, the bottom of the Air bags fold in/around a flattish 'puck' that's the baseplate bolted to the swing arm. This means that when there's enough pressure in there, the bag won't be in contact with the swing arm around where the bag is mounted, and the pressure can go up whenever air gets added by the compressor during ryding, which'll extend the bag & raise the folded bit. But if the air bag's been run at low enough height/pressure that it's been in contact with the swing arm for long enough to wear any tiny holes in it cos it was sitting on top of any fine grit/gravel that'd been thrown up from the road, then the raising/extenting of the air bag will expose any potential leaks/holes that may've been caused by that fine grit/small gravel getting caught in between the air bag & the swing arm - and those tiny little holes (in my first air bag failure, they were bloody near microscopic holes, but there was a whole bunch of 'em! ) will then slowly leak until the bag looses enough pressure that it once again collapses down & rolls the portion of bag with the leaks in it in & under/around the puck/baseplate, effectively sealing the leaks again by forcing them reeeaaally tightly against the baseplate/puck until more air is added & exposes them again! :banghead: And there's other possibilities of similar 'higher pressure leak' scenario's too, especially with the 'push fit' air line connections & the 'release valve' itself.... I found a release valve just this last week that had it's air line connectors only screwed in finger tight, but they had some yellow goop on them (lockight?) that seemed to work OK as a sealer at low pressure, only to leak like a seive at anything over about 30 psi! Same result, similar problem, & a right pain to find.... the ACS worked OK when ryding, but leaked air pressure down to about 20psi once it was stopped & let sit for a day or two! :dontknow:

It wouldn't really be all that hard or expensive to design & deliver an ACS that worked properly, maybe BRP could even use a taller baseplate that's got a tapered raised piston that goes up inside the collapsing/low pressure bag just like all those that work so well & reliably for millions of miles on many heavy vehicles - just so that the bag itself only touches the almost vertical tapered sides of that piston & never actually contacts or puts any load &/or wear on the swing arm, where stuff can get caught on the almost horizontal surface between bag & arm, which is what causes the wear & creates these minute little holes.... But like I've said before, it's a great concept BRP have used here, just not so great an execution of that concept! :gaah:

 

[2dogs]

" LEAKING " ..... and it is stopping at 25lbs. ... why would it STOP at 25lbs. ????? .... Mike :thumbup:

BUDS may be set at 25?

 

[Bfromla]

Any harm in small spray of soapy water at valve & around air bag for double checking:dontknow: of course inspect & avoid any electrical in area

 

[IdahoMtnSpyder]

" LEAKING " ..... and it is stopping at 25lbs. ... why would it STOP at 25lbs. ????? .... Mike :thumbup:

It isn't clear to me that the pressure actually stopped at 25 psi, or if that's just where it happened to be twice when the OP checked it. Leaks can be strange. My heat pump system had a leak that apparently stopped when the pressure got low enough. The system kept working but not like it was supposed to. Another time years ago I had a solder joint leak in a water pipe. The leak stopped when the system pressure was reduced.

 

[Joel The Biker]

That is normal. The pressure will increase and decrease as needed with the onboard compressor. The compressor does not fill untill you put the spyder in gear. It can be hard to hear. It will turn off automatically when the proper ride height is reached. If the compressor fails, you will get a suspension fault code. The onboard computer does not monitor the air pressure in the airbag. It only uses a reference number from the rear suspension height sensor which is unique to each spyder. There is a process to calibrate the sensor when needed. On spyders that have a manual fill airbag, a reference air pressure tag is provided to get you in the ballpark for best ride comfort. If you had a leak in the airbag, the pressure would quickly go to zero. A leak in an airline or fitting would also eventually go to zero, but may take longer. Your symptoms appear to be normal operation to me.

 

[BLUEKNIGHT911]

BUDS may be set at 25?

This what the OP said !!!! .............Mike :thumbup:

 

[IdahoMtnSpyder]

I just read through the 2014 service manual about the rear suspension. The only settings in BUDS related to the air bag is a reset of the setting for high and low positions above ground as gauged by the position sensor. I don't find anything that indicates the air pressure is automatically released when the bike is shut off. I'm pretty sure that with no leaks the pressure in the air bag just before the bike is started will the same pressure when it was shut down.

 

[Joel The Biker]

This is correct. BUDS does NOT monitor air pressure in the airbag. It only uses a reference number from the height sensor to decide whether or not to add or release air from the airbag. Also, if you park your spyder, set parking brake, get off your spyder and then turn it off, the computer will let air out of the airbag because the bike is still in gear and the suspension height increases when you get off. Mine does this when I pull out of the garage, then get off to go inside and get something. As soo as I step off, I hear it release air.

 

[Mikey]

On pretty much anything else, that leak down then stop at a pressure like 25 psi might be unlikely, but in this case, the bottom of the Air bags fold in/around a flattish 'puck' that's the baseplate bolted to the swing arm. This means that when there's enough pressure in there, the bag won't be in contact with the swing arm around where the bag is mounted, and the pressure can go up whenever air gets added by the compressor during ryding, which'll extend the bag & raise the folded bit. But if the air bag's been run at low enough height/pressure that it's been in contact with the swing arm for long enough to wear any tiny holes in it cos it was sitting on top of any fine grit/gravel that'd been thrown up from the road, then the raising/extenting of the air bag will expose any potential leaks/holes that may've been caused by that fine grit/small gravel getting caught in between the air bag & the swing arm - and those tiny little holes (in my first air bag failure, they were bloody near microscopic holes, but there was a whole bunch of 'em! ) will then slowly leak until the bag looses enough pressure that it once again collapses down & rolls the portion of bag with the leaks in it in & under/around the puck/baseplate, effectively sealing the leaks again by forcing them reeeaaally tightly against the baseplate/puck until more air is added & exposes them again! :banghead: And there's other possibilities of similar 'higher pressure leak' scenario's too, especially with the 'push fit' air line connections & the 'release valve' itself.... I found a release valve just this last week that had it's air line connectors only screwed in finger tight, but they had some yellow goop on them (lockight?) that seemed to work OK as a sealer at low pressure, only to leak like a seive at anything over about 30 psi! Same result, similar problem, & a right pain to find.... the ACS worked OK when ryding, but leaked air pressure down to about 20psi once it was stopped & let sit for a day or two! :dontknow:

It wouldn't really be all that hard or expensive to design & deliver an ACS that worked properly, maybe BRP could even use a taller baseplate that's got a tapered raised piston that goes up inside the collapsing/low pressure bag just like all those that work so well & reliably for millions of miles on many heavy vehicles - just so that the bag itself only touches the almost vertical tapered sides of that piston & never actually contacts or puts any load &/or wear on the swing arm, where stuff can get caught on the almost horizontal surface between bag & arm, which is what causes the wear & creates these minute little holes.... But like I've said before, it's a great concept BRP have used here, just not so great an execution of that concept! :gaah:

Come on Peter, you're talking silly now, that makes too much sense there, stop it!!!!

 

[Mikey]

It could be the start of a weak dump valve, that is just dirty enough to leak down at high pressure and happens to stop at or around 25 lbs, I would go out for a ride and come back and put the soapy water to the system just for peace of mind! If you don't see any leaks then just chalk it up to that's how it works, and if you find a leak, you have saved your compressor for a short life!!! Sooner or later, I believe it will happen! Thank you BRP!!!

 

[davev1pa]

Should I be worried. 2019 RTL with air bag. It has always held air without any problems. I never hear the on board air compressor run. Must be my hearing. Last Sunday, I checked air in the air bag before leaving on a 2 hour ride and it checked at 25 lbs. Rode two hours and on my return it checked at 43 lbs which is where it usually had been. Checked last night and it as back to 25 lbs. Is this a sign of a leaky air bag or just the season of the year and fluctuating air pressure due to changes in the outside temperature? Since I can't hear the air compressor I don't know if it's constantly running.

No worries-it's normal. I would confirm with an audiologist or another hearing individual to confirm the compressor operation. I can both hear and feel mine operating.