Fox 38 stuck down airspring (brand new)

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Fox 38 stuck down airspring (brand new)
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flag Blownoutrides
O+
Posted: May 13, 2022 at 10:38 Quote
Aired down my brand new 38 to access volume spacers and it immediately sucked down into full compression. Removed the lowers and the airspring (took some serious hunker to yank it out). Airspring is fully sucked down (shaft pulled all the way up).

Any ideas??
flag kiranseligman
O+
Posted: May 24, 2022 at 18:18 Quote
You have any pics of it? Is the air spring out of the fork?
flag Blownoutrides
O+
Posted: May 25, 2022 at 0:55 Quote
kiranseligman wrote:
You have any pics of it? Is the air spring out of the fork?

It’s out of the fork. I replaced it with a new one. No pics but the shaft is fully compressed up into the airspring
flag kiranseligman
O+
Posted: May 25, 2022 at 6:16 Quote
Without seeing pics it’s tricky to say for sure. But I think it is normal. As long as the retaining clip on the air spring is properly seated then reinstall the lowers and add air. It should come back. You can add a small amount of air to the spring before reinstalling the lowers to make it easier to screw the bolts on.
flag CSdirt
Posted: May 25, 2022 at 8:36 Quote
sounds like you released all the air at once? Doing that is bad. You got to let out a small amount of air at a time, then stop, and cycle the air from the positive to negative chamber. If you dont cycle the air between chamber then it sucks down on the negative side like a vise.
flag Blownoutrides
O+
Posted: May 25, 2022 at 14:43 Quote
CSdirt wrote:
sounds like you released all the air at once? Doing that is bad. You got to let out a small amount of air at a time, then stop, and cycle the air from the positive to negative chamber. If you dont cycle the air between chamber then it sucks down on the negative side like a vise.

Yup. I now let the air out ever so slowly with the button on my shock pump rather than quick with a hex key. I seem to learn everything the hard way. This lesson cost $140 US Smile . I suppose I could try to salvage it but it would require tearing down my fork again so I’ll pass for now. Lesson learned - don’t let the air out fast and definitely don’t use the equalization buttons with the fork aired down.
flag kiranseligman
O+
Posted: May 25, 2022 at 17:17 Quote
Blownoutrides wrote:
CSdirt wrote:
sounds like you released all the air at once? Doing that is bad. You got to let out a small amount of air at a time, then stop, and cycle the air from the positive to negative chamber. If you dont cycle the air between chamber then it sucks down on the negative side like a vise.

Yup. I now let the air out ever so slowly with the button on my shock pump rather than quick with a hex key. I seem to learn everything the hard way. This lesson cost $140 US Smile . I suppose I could try to salvage it but it would require tearing down my fork again so I’ll pass for now. Lesson learned - don’t let the air out fast and definitely don’t use the equalization buttons with the fork aired down.

What did you have to spend the money on?
flag Blownoutrides
O+
Posted: May 25, 2022 at 22:09 Quote
kiranseligman wrote:
Blownoutrides wrote:
CSdirt wrote:
sounds like you released all the air at once? Doing that is bad. You got to let out a small amount of air at a time, then stop, and cycle the air from the positive to negative chamber. If you dont cycle the air between chamber then it sucks down on the negative side like a vise.

Yup. I now let the air out ever so slowly with the button on my shock pump rather than quick with a hex key. I seem to learn everything the hard way. This lesson cost $140 US Smile . I suppose I could try to salvage it but it would require tearing down my fork again so I’ll pass for now. Lesson learned - don’t let the air out fast and definitely don’t use the equalization buttons with the fork aired down.

What did you have to spend the money on?

A new air spring. I’m sure I could’ve eventually prevailed on either the DIY fix or warranty fronts but for $140 the problem is solved and I get to spend that time riding or with the fam. Choose your battles lol
flag Bgcookk
O+
Posted: Jul 24, 2022 at 13:33 Quote
Blownoutrides wrote:
CSdirt wrote:
sounds like you released all the air at once? Doing that is bad. You got to let out a small amount of air at a time, then stop, and cycle the air from the positive to negative chamber. If you dont cycle the air between chamber then it sucks down on the negative side like a vise.

Yup. I now let the air out ever so slowly with the button on my shock pump rather than quick with a hex key. I seem to learn everything the hard way. This lesson cost $140 US Smile . I suppose I could try to salvage it but it would require tearing down my fork again so I’ll pass for now. Lesson learned - don’t let the air out fast and definitely don’t use the equalization buttons with the fork aired down.

I did this too, bought a brand new air spring and cycled it up 10psi at a time and it’s still sucking down. Anybody have any idea what’s going on? I bought the new spring because my old one was sucking down too. It’s been very annoying that I can’t seem to get my fork to full travel no matter what.
flag loudv8noises
O+
Posted: Jul 26, 2022 at 10:44 Quote
sounds like transfer port is blocked by grease.

completely air down the fork
unscrew the air cap (24mm) and remove
sit on front tire and push up hard on the bars to fully extend fork

The grease should clear. You're going to want to get the excess grease out of there or it will clog the transfer port up again.

replace cap, fill air cycling every 10psi or so to equalize pos and neg air chambers

fork should now extend to full travel.
flag Blownoutrides
O+
Posted: Jul 26, 2022 at 10:53 Quote
loudv8noises wrote:
sounds like transfer port is blocked by grease.

completely air down the fork
unscrew the air cap (24mm) and remove
sit on front tire and push up hard on the bars to fully extend fork

The grease should clear. You're going to want to get the excess grease out of there or it will clog the transfer port up again.

replace cap, fill air cycling every 10psi or so to equalize pos and neg air chambers

fork should now extend to full travel.

Tried that, no dice. Thing was just stuck for good.
flag 16rally
Posted: Jul 26, 2022 at 11:28 Quote
I'm going to ask for a quick explanation/education:
If the air spring gets stuck in the down position due to positive air being let out, why can't one re-inflate the air spring to get it to expand again?
I understand that would take things back to square one if the transfer ports are clogged with grease, but at least it should get the air spring to extend and become somewhat functional again.
flag mitch1992
O+
Posted: Jul 27, 2022 at 13:48 Quote
16rally wrote:
I'm going to ask for a quick explanation/education:
If the air spring gets stuck in the down position due to positive air being let out, why can't one re-inflate the air spring to get it to expand again?
I understand that would take things back to square one if the transfer ports are clogged with grease, but at least it should get the air spring to extend and become somewhat functional again.

Yes you can do exactly that to get yourself back to square one. If it is grease blocking the ports, one could try cycling the fork to get said grease away from the port so that when air is released, it can pass through the port to equalize/deflate the negative chamber.

I think it is imperative to understand the fork is not "sucking down" due to a vaccum in the negative chamber but more that it is being held up due to air pressure in the negative side. Effectively, it is a fork in reverse. The air pressure in the negative is pushing the airspring the opposite way (toward the top of the fork) which compresses/sucks the fork down into its travel.

Its key when releasing air to do it slowly. Use the bleed valve on a shock pump instead of depressing the schrader valve with a sharp tool. Also try and hold the fork extended. This will help keep the port in the right area so air can actually flow between the negative and positive side.

If you manage to get it deflated without it sucking down, take the airspring apart and see what is blocking the transfer port. There is no logical reason for it to be sucked down other than the port has not allowed air to bypass the spring head, either not in the right spot or its blocked.
flag mitch1992
O+
Posted: Jul 27, 2022 at 14:47 Quote
Here are a couple of helpful videos to understand airsprings and how they work. Not trying to tell people how to suck eggs but watching these sometimes make something click in your brain.

Too much grease: https://www.youtube.com/watch?v=haRbXlQiTHY

Float airspring how it works: https://www.youtube.com/watch?v=03pdywBkuNQ

Trying to remove grease in chamber without dissasembling: https://www.youtube.com/watch?v=Y-UfHFI4-MM
flag Bgcookk
O+
Posted: Jul 28, 2022 at 21:24 Quote
mitch1992 wrote:
16rally wrote:
I'm going to ask for a quick explanation/education:
If the air spring gets stuck in the down position due to positive air being let out, why can't one re-inflate the air spring to get it to expand again?
I understand that would take things back to square one if the transfer ports are clogged with grease, but at least it should get the air spring to extend and become somewhat functional again.

Yes you can do exactly that to get yourself back to square one. If it is grease blocking the ports, one could try cycling the fork to get said grease away from the port so that when air is released, it can pass through the port to equalize/deflate the negative chamber.

I think it is imperative to understand the fork is not "sucking down" due to a vaccum in the negative chamber but more that it is being held up due to air pressure in the negative side. Effectively, it is a fork in reverse. The air pressure in the negative is pushing the airspring the opposite way (toward the top of the fork) which compresses/sucks the fork down into its travel.

Its key when releasing air to do it slowly. Use the bleed valve on a shock pump instead of depressing the schrader valve with a sharp tool. Also try and hold the fork extended. This will help keep the port in the right area so air can actually flow between the negative and positive side.

If you manage to get it deflated without it sucking down, take the airspring apart and see what is blocking the transfer port. There is no logical reason for it to be sucked down other than the port has not allowed air to bypass the spring head, either not in the right spot or its blocked.

Went to a suspension pro this weekend and found out a couple good things, mostly all of what you said here! Also found that fox and rockshox forks have a certain level of “suck down” that is normal. There are ports on the bottom of the air shaft that it has to come over in order to function properly, they are a few mm above the end of the shaft. Measure your air shaft and even with this ride down it will be at your recommended travel. If it’s not, take it apart and clean the grease and get chamber to pressurize. But fear not for a few mm! Helped ease my worries a lot.
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