How to decrease charge on 2.5 fox shocks?

I had my 4 shocks rebuilt and the fronts are perfect... But the rears are WAY stiffer than the ones I took off of the truck (the rears weren't leaking I should have just left them but I was trying to be proactive). On the stock shocks the nitrogen pressure is what controls the stiffness/softness of the shock, correct? I have a scab so I'm wondering if the shocks were sent back to me charged a little harder for a screw... Is there any way to decrease the charge without sending them back off to a shock shop? Think reducing charge would fix my issue?

When the front of the truck drops over my steep curb it acts perfectly... Super soft landing like it should... But when the rear drops off it jars the entire truck with a very firm landing.

You will need a needle valve from Fox to adjust the psi. Standard charge for all 2.5's is 200 psi. That's what should have been in them when new. Maybe it's just been so long that you don't recall the ride.......

Check on Fox's website, I think the gauge and inflator valve are in there. If not, just give me a call and I will order one for you if you want.

Good luck!!!

We sell a replacement endcap for the Stock shocks.. w/ Schrader Valve. $35 each

2014RubyRed said:

You will need a needle valve from Fox to adjust the psi. Standard charge for all 2.5's is 200 psi. That's what should have been in them when new. Maybe it's just been so long that you don't recall the ride.......

Check on Fox's website, I think the gauge and inflator valve are in there. If not, just give me a call and I will order one for you if you want.

Good luck!!!

Click to expand...

@RPG

Just FINALLY got around to buying a little gadget that has a needle, gauge, and shrader valve all in one. This should allow me to (if I can access the little holes on the shocks without removing them off the truck) push the needle into the shock and then use the back end of a tire pressure gauge to drain some of the pressure out of the shock correct? I had the shocks rebuild by the ROC team and after re-reading their "DIY rebuild thread" they advised airing all 4 shocks up to 240 psi NOT the 200 psi you stated earlier in this thread. Hopefully THAT is my issue.

The little rubber "holes" that you puncture with the needle are on the Allen screws on the shocks right? These rubber "holes" are not one time use right? After I push the needle through when I pull the needle back out it will continue to hold the rest of the pressure right? Just making sure I'm not going to have to pull the screw out after, replace the punctured seal, and then find a tank of nitrogen to air back up to 200 psi.


Thanks for you help! I'm really hoping the 240 vs 200 is the issue im having! 200 psi front and back right?

Can you access both the Allen screws with the truck still installed? I haven't been out to the truck to check on that yet

grantoser said:

@RPG
Can you access both the Allen screws with the truck still installed? I haven't been out to the truck to check on that yet

Click to expand...

If it was me, I would pull the rear shocks to do this. It's gonna be a bear to do it with the shocks on the truck. It isn't too bad removing the rear shocks. I just replaced a set for another customer and pulled the old shocks off and installed the new ones in about 1/2 an hour. Make sure to use a sharpie and mark the shock shaft where it is sitting right now so you can compress the shocks back to that position to re-install. They will 'grow' a little when you pull them out. Best to jack the rear of the truck as far as you can. Put a block under the trailer hitch and jack it right there. You will want the reared at full droop, but don't jack the rear wheels off the ground. It sounds a lot harder than it is, but I think it will make it much easier for you to adjust the pressures.

Good luck!!! Let us know how it goes. Make sure to chock the front wheels so the truck doesn't roll away from you.....

grantoser said:

@RPG

Just FINALLY got around to buying a little gadget that has a needle, gauge, and shrader valve all in one. This should allow me to (if I can access the little holes on the shocks without removing them off the truck) push the needle into the shock and then use the back end of a tire pressure gauge to drain some of the pressure out of the shock correct? I had the shocks rebuild by the ROC team and after re-reading their "DIY rebuild thread" they advised airing all 4 shocks up to 240 psi NOT the 200 psi you stated earlier in this thread. Hopefully THAT is my issue.

The little rubber "holes" that you puncture with the needle are on the Allen screws on the shocks right? These rubber "holes" are not one time use right? After I push the needle through when I pull the needle back out it will continue to hold the rest of the pressure right? Just making sure I'm not going to have to pull the screw out after, replace the punctured seal, and then find a tank of nitrogen to air back up to 200 psi.


Thanks for you help! I'm really hoping the 240 vs 200 is the issue im having! 200 psi front and back right?

Can you access both the Allen screws with the truck still installed? I haven't been out to the truck to check on that yet

Click to expand...

This isn't something I would suggest doing while the shocks are on the truck. Can it be done? Maybe, never tried. However, if you end up with a bad rubber pellet in any of the shocks they will have to be removed for replacement. The rubber pellets are the seals that must be punctured by the fox needle. Just want to be clear that you got the Fox needle right? A regular needle like you would use for a football or something will not work. If the needle stays pristine you may be able to peirce both rear shocks and drain pressure but with the shocks mounted on the truck this may be challenging as they have to be inserted just right to avoid damage. Also if you feel resistance stop. Correct your angle and try again. I just rebuilt my front shocks here at home and upon removing the needle during pressure charge the seal took a little time to self seal. This is possibly why the higher pressure at initial fill.

Honestly the RPG scrader valves may be the way to go if you will be adjusting things regularly to get the right feel you are looking for without upgrading. Plus they are easier to work with than a needle. If you are going to attempt this with the shocks mounted consider having some rubber pellets on hand just in case you discharge a shock and the pellet is damaged or just goes bad as is common if you have to poke them more than a couple times. Good luck.

grantoser said:

@RPG

Just FINALLY got around to buying a little gadget that has a needle, gauge, and shrader valve all in one. This should allow me to (if I can access the little holes on the shocks without removing them off the truck) push the needle into the shock and then use the back end of a tire pressure gauge to drain some of the pressure out of the shock correct? I had the shocks rebuild by the ROC team and after re-reading their "DIY rebuild thread" they advised airing all 4 shocks up to 240 psi NOT the 200 psi you stated earlier in this thread. Hopefully THAT is my issue.

The little rubber "holes" that you puncture with the needle are on the Allen screws on the shocks right? These rubber "holes" are not one time use right? After I push the needle through when I pull the needle back out it will continue to hold the rest of the pressure right? Just making sure I'm not going to have to pull the screw out after, replace the punctured seal, and then find a tank of nitrogen to air back up to 200 psi.


Thanks for you help! I'm really hoping the 240 vs 200 is the issue im having! 200 psi front and back right?

Can you access both the Allen screws with the truck still installed? I haven't been out to the truck to check on that yet

Click to expand...

yes it should work but remove the shocks before discharging any air if the shocks under load it can cause the air to release more rapidly and you might not be able to control the amount of nitrogen you let out. it doesn't take much to drop it from 240 to 200. also the rear might seem a little stiffer because its a lot lighter than the front of the truck. if you carry anything in the bed when you go off road try loading that all in the bed then drive it around and see what you think. dropping the psi will make it smoother on road and just right but might make it too soft off road. the rubber pellet will seal itself unless its a bad pellet like stated before. as for the fronts leave them at 240 right now. the front is a lot heavier and needs that extra pressure to keep it from bottoming out. if you are on mid perch you could drop the psi to 220 but that's as low as I would go. hope this all helps

2014RubyRed said:

If it was me, I would pull the rear shocks to do this. It's gonna be a bear to do it with the shocks on the truck. It isn't too bad removing the rear shocks. I just replaced a set for another customer and pulled the old shocks off and installed the new ones in about 1/2 an hour. Make sure to use a sharpie and mark the shock shaft where it is sitting right now so you can compress the shocks back to that position to re-install. They will 'grow' a little when you pull them out. Best to jack the rear of the truck as far as you can. Put a block under the trailer hitch and jack it right there. You will want the reared at full droop, but don't jack the rear wheels off the ground. It sounds a lot harder than it is, but I think it will make it much easier for you to adjust the pressures.

Good luck!!! Let us know how it goes. Make sure to chock the front wheels so the truck doesn't roll away from you.....

Click to expand...

@RPG

Well this isn't what I expected lol. I was able to put a needle and gauge on all 4 shocks today. I actually didn't end up even taking the shocks off. I use needles in tight places for a job so i felt comfortable getting them in all 4 shocks.

So I was thinking the rears were too pressurized... I was wrong.
Drivers rear: 105psi
Passenger rear: 155psi

Sure was surprised to see these numbers... I guess the jarring rear I've been feeling is just because I have very low amount of dampening happening back there. I'm surprised I don't notice the truck bouncing around in the rear it's more just a rough feel in the back.

Now for the fronts:

Drivers front: 260psi
Passenger front: 255psi

I ended up dropping both the fronts to 230psi. I figured I'm going to have to figure out how to get nitrogen for the rears so if I didn't like the decreased fronts I could air them up then. I really like the front ride at 230psi now in the front. More of a cushy ride over bumps but still doesn't nose dive during stopping.

So fronts are figured out but now I've gotta figure out the rears. Can these shocks leak nitrogen? I JUST Had them rebuilt by the ROC team but I guess maybe one of the seals wasn't seated all the way or something. Just thought I'd give you guys an update. Little frustrating thought I'd have it all figured out today!

grantoser said:

@RPG

Well this isn't what I expected lol. I was able to put a needle and gauge on all 4 shocks today. I actually didn't end up even taking the shocks off. I use needles in tight places for a job so i felt comfortable getting them in all 4 shocks.

So I was thinking the rears were too pressurized... I was wrong.
Drivers rear: 105psi
Passenger rear: 155psi

Sure was surprised to see these numbers... I guess the jarring rear I've been feeling is just because I have very low amount of dampening happening back there. I'm surprised I don't notice the truck bouncing around in the rear it's more just a rough feel in the back.

Now for the fronts:

Drivers front: 260psi
Passenger front: 255psi

I ended up dropping both the fronts to 230psi. I figured I'm going to have to figure out how to get nitrogen for the rears so if I didn't like the decreased fronts I could air them up then. I really like the front ride at 230psi now in the front. More of a cushy ride over bumps but still doesn't nose dive during stopping.

So fronts are figured out but now I've gotta figure out the rears. Can these shocks leak nitrogen? I JUST Had them rebuilt by the ROC team but I guess maybe one of the seals wasn't seated all the way or something. Just thought I'd give you guys an update. Little frustrating thought I'd have it all figured out today!

Click to expand...

Yes , if the rubber pellet that you puncture with the needle is bad or has a slow leak they will lose nitrogen . usually if the other seals didn't seat they leak oil . those little rubber plugs do go bad . When we rebuild we try to keep the shocks charged up for one full day before shipping back to customers. But sometimes people are in a hurry to get theirs back . try recharging them and see if they hold the charge .

DezertRacer said:

Yes , if the rubber pellet that you puncture with the needle is bad or has a slow leak they will lose nitrogen . usually if the other seals didn't seat they leak oil . those little rubber plugs do go bad . When we rebuild we try to keep the shocks charged up for one full day before shipping back to customers. But sometimes people are in a hurry to get theirs back . try recharging them and see if they hold the charge .

Click to expand...

Any suggestion on where I can buy a nitrogen tank/regulator? Or can i rent one?