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Should the air shocks bleed air over time?


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If I set it on medium front and back it bleeds out overnight. What is considered normal for these bikes?
Mine too, does that mean only the seals are likely to need replacing or is there anywhere else that should be checked for leaks before diving into the forks?
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Take it up to max pressure and start with the soapy water to find the leak.

My 88 only needs the air in the suspension checked once in the spring when it comes out of storage. I have not had to add air to the rear shock for the last 2 years. The front needs 2 or 3 lbs added once a year.

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Take it up to max pressure and start with the soapy water to find the leak.
My rear shock appears to hold air OK so the problem is probably confined to the front one. How much disassembly is required to get to the air lines for the forks?
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The air line runs all the way from under the trunk to the top bridge. To get to all of it you'd have to disassemble a lot.

 

The fork seals themselves seem like the likeliest suspect.

 

The connectors at the top of the forks are simply rings with o-rings in them to seal to the forks. Since since each has 2 o-rings and they need to be slid off to service the forks they also seem like good points to start your search.

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Take it up to max pressure and start with the soapy water to find the leak.

My 88 only needs the air in the suspension checked once in the spring when it comes out of storage. I have not had to add air to the rear shock for the last 2 years. The front needs 2 or 3 lbs added once a year.

 

 

Ditto, I check my shock air once in a blue moorn and the air pressure is the same even after the entire riding season. Anything less indicates a leak.

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the front forks should not cause the rear shock to lose air. There is a seperation valve. Otherwise whatever you set the rear would also be in the front. So if they both are losing air. It's a hose/system issue(s) for sure. ALso the rear is an air bladder on top of a spring. It's rubber...now old rubber. Like an old tire air evenually gets through. Me I just top up the rear air once a month 1 or 2 psi. I lose more checking it than it is really losing.

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  • 5 months later...

I guess Jurob never got to fix this. I wish I would have realized it BEFORE I reassembled everything!!!!

 

I am losing pressure in the system. The front forks seals are not leaking but I am losing pressure overnight both front & back. So I will start spraying soapy water.

 

...It's a hose/system issue(s) for sure. ALso the rear is an air bladder on top of a spring. It's rubber...now old rubber. Like an old tire air evenually gets through.

 

So it's quite possible the bladder in the shock is bad???

Would that cause the front to lose pressure??

 

To quote Michael Corleone:

Just when I thought I was out... they pull me back in. http://profile.ak.fbcdn.net/hprofile-ak-ash2/161426_100000987689140_7084582_q.jpg

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Also another question that comes to mind. There are 2 setting on the controller: Automatic & Manual

 

Does this mean that on automatic the sysyem will maintain set pressure while riding?

or does it mean that it will fill to preset values initially?

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The controller doesn't get power with the motorcycle on, Automatic just lets you set High, Medium, or Low rather than holding the little buttons forever. It doesn't monitor at all.

 

The only common point between the front and rear is the valve body and compressor. I'd start looking for leaks there.

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The only common point between the front and rear is the valve body and compressor. I'd start looking for leaks there.

 

I filled it this afternoon to 17Front / 71Rear and just checked I was down to 12 Front / 46 Rear. I just don't know what timme I filled. I just refilled it, I will check in 1 hour to see the rate of decay.

 

I do know that eventually I will 0 out.

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... I will check in 1 hour to see the rate of decay.

 

Ok so here is my figures:

Filled front & rear to high

 

@5:00 pm

R 71 psi

F 17 psi

@6:00 pm

R 59 psi minus 12

F 14 psi minus 3

@7:00 pm

R 50 psi minus 9

F 14 psi minus 2

@8:00 pm

R 41 psi minus 9

F 11 psi minus 1

@9:00 pm

R 31 psi minus 10

F 9 psi minus 2

@10:00pm

R 23 psi minus 8

F 8 psi minus 1

 

So I am averaging a pressure loss of 9.6 psi per hour at the rear and 1.8 psi per hour at the front. Then by my calculations would deplete the air in around 8 hours, no small leak.

 

I see that there are 4 lines & barring multiple leaks, the front & rear are independent after the valve SO... If it's a line, it's either the compressor to dryer or the dryer to solenoid valve line...or the countless O-rings in between.

 

On the bright side all the electronic components work and I'll take this opportunity to replace the silica gel in the dryer.

I just hope it turns out to be a weak O-ring & not something expensive.:detective:

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If you are loosing air that bad, chances are that there is\was moisture in the solenoids and that the seal seats are now corroded and so let air out. If you don't look after the silica gel every other year this will happen.

For the gel, carefully take it out of the canister, lay it on a plate, cover with a cloth and nuke for about 2 minutes. It should now be blue and ready to use again, just like new.

 

For the solenoid, take them apart, two screws holding each one on, and there are three, clean them and look down inside the cylinder. You'll see where the rubber seat sets. You should see nice smooth aluminum, but more than likely you'll find a bit of corrosion. Get yourself a 6 inch piece of wood doweling, wind some steel wool around the one end and hold it in place with a piece of black tape. Insert the other end into a drill and now you can polish the seat back to new again. Careful as you take the unit apart as there are small springs inside that seat the seal. Once it's all cleaned, blow it out with air and put it back together,,,, no lube required.

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I filled it this afternoon to 17Front / 71Rear and just checked I was down to 12 Front / 46 Rear. I just don't know what timme I filled. I just refilled it, I will check in 1 hour to see the rate of decay.

 

I do know that eventually I will 0 out.

 

Think about this for a minute. I thought that I had the same problem as you do.

I also thought I was losing air on my 86 VR. Mine was happening anywhere from hours to minutes making me thing I had a bad leak. Fortunately I posted here and found that I didn't have an air leak at all.

I had bad solder joints on the controller board which were causing me to lose air.

 

 

 

Actually the bad joints caused a a few problems

  • Even though the LCD said I was at target pressure, I never was. This was the big problem because of bullet #2
  • As soon as the target pressure is reached, the relief valve opens and releases most of the pressure. It takes a lot less time to get to 0 if you never actually reached the target pressure. See bullet #1
  • It didn't happen until I got deep in to the problem but I eventually received an error code on the display. The problem existed long before the code showed up.

It will take you less than 20 minutes to check the solder joints on your controller board. Its a whole lot easier than chasing down air line leaks.

Many thanks to this forum! You saved me a lot of time and aggravation.

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Ok so I have a lot of GREAT ideas here for troubleshooting.

Good thing it's January and cruising doesn't start until May (and that I have my Honda)

I have 4 months to get her up to snuff.

 

Ray, even with bad solders I do fill up (i feel it) and if it's even if it's not filling to what it says, why would the system purge the pressure? Unless the CLASS is signaling the solenoid valve to purge.

 

Carl the concern about the solenoid valve seals seats being corroded and let air out could really be a possibility. My understanding is this bike's original owner died & the bike sat awhile. It only has 14K original mile so I'm sure the desiccant was NEVER done at all.

 

 

I'm not really happy with the way the front forks respond to bumps in the road, even with 17 psi up front. Plus I will check the bearings since the front feels funny not wobbly just funny...not too bad just, not like my CB 750. Unless it's that I'm not used to the weight of the fairing.

I have also read about progressives for the front forks?

What are these? anyone have any links to vendors?

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Ray, even with bad solders I do fill up (i feel it) and if it's even if it's not filling to what it says, why would the system purge the pressure? Unless the CLASS is signaling the solenoid valve to purge.

 

Prior to re-soldering the pins, my LCD would display the target pressure in seconds. I could feel the bike start to rise and then at the ends of each cycle the relief valve would purge a small amount of air. Now since I never actually reached the target value, that small amount of air was significant and enough to take me back to 0. I even thought that my purge valve might be bad but it wasn't.

 

The 2 biggest changes after re-soldering the pins is that it takes 3X as long to get to the target pressure and now it holds it indefinitely.

 

I agree that both of our problems sound like air leaks. I was certain that mine was which is why I waited until the off season to tackle it only to find that it was actually bad connections. BTW, I never get that lucky. This was a first for me!

 

Ray

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Spending $70 on Progressive springs on the front will give you better suspension than any amount of air pressure.

 

You can do the same on the rear too, it just costs a little more (maybe $100 for the spring).

 

Then you can forget the CLASS system, which was a great idea but not as good an idea as fitting decent suspension in the first place :)

 

Any one tried turning the CLASS compressor into a tire inflator?

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Prior to re-soldering the pins, my LCD would display the target pressure in seconds. I could feel the bike start to rise and then at the ends of each cycle the relief valve would purge a small amount of air. Now since I never actually reached the target value, that small amount of air was significant and enough to take me back to 0. I even thought that my purge valve might be bad but it wasn't.

 

Ok I do hear a slight purge after I fill

 

I think I will check the solders 1st since that is an easy fix. Plus even though I filled it up it still feels like the front end is not cushioning the ride like it should.

 

Did you just do the pins or all the board solders?

 

BTW I just took the bike out for a hard ride to pump some Seafoam into the carbs. Man this bike can fly!

I had her up to 90 without realizing it. At highway speeds she is smooth as silk!

I did feel a small vibration at low 30mph when turning (right or left) onto another block, is this a normal feel?

 

This bike is so much fun it's FREAKY!:cool10:

Edited by cabreco
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...Plus I will check the bearings since the front feels funny not wobbly just funny...not too bad just, not like my CB 750. Unless it's that I'm not used to the weight of the fairing.

 

Well sometime you overlook the obvious. 10psi at the front tire 23 at the rear DUH!

Filled it to specs and she corners much better. I did a quick check on the looseness of the tree bearings by lifting her off the ground & seeing if the the forks drop to either side by themselves (they did not) I also did the bounce test by tossing the front to once side & letting her bounce back. She bounced off the stop & stopped.

 

I also took by hands off the grips & she doesn't wobble. It's just a slight grinding-ish feel I get at the grips when turning. It may be a dragging caliper though. (the more I type the more I think of stuff)

 

I welcome any thoughts of what else to check.

Thanks

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