Fox DHX 3.0 rear shock

jimbo-norco

Why does my Rear shock (named above) keep losing pressure? Im getting worried now incase its going to cost me lots! when I first had the bike I checked the pressure it was a 140psi, then I checked it a few weeks later and it was at 110psi, then a week later it was 90psi. i know this doesnt sound much, but to test it I put 200psi in the rear shock, then rode it for a bit, then checked it a week later and it was at 150psi! help! :roll:

supersonic

How old is it? Are you losing pressure by simply checking it, or do you notice the feel is changing then check it? Faulty valve or seals.

jimbo-norco

it began to feel looser so I checked it and it was low. its only 7 months old! thats what worries me!

supersonic

Shouldn't be losing air like that. I'd contact the retailer if it was bought new, if not, send it to mojo.

nicklouse

Every time you attach the pump you will get a lower reading than it is.

try it a few times. now.

jimbo-norco

yes but 50 psi in one go? it wouldnt lose that much would it?

supersonic

Thats what I initially thought it might be, but he reports a feeling of it losing pressure on the trails too. But you never know!

nicklouse

jimbo-norco wrote:

yes but 50 psi in one go? it wouldnt lose that much would it?

like i said set the air now and then remove the shock pump. now reattach it and see what it says.

sonic dont forget the DHX3 is not an air shock and the air chamber is very small and a quite high pressure.

nicklouse

DHX 3 what? air or coil? and which air chamber? the boost valve? or if the DHX air 3 the main chamber?

rob cole

it shouldn't lose that much pressure, it will lose perhaps 5 psi when you disconnect the pump


shock is 7 months old?

so well within the 12 month warranty period

have your bike shop send it back to Mojo, you will need to give your shop a copy of your receipt

nicklouse

rob cole wrote:

it shouldn't lose that much pressure, it will lose perhaps 5 psi when you disconnect the pump

Again with out knowing what he is doing to what with what you can not say that 5 PSI is normal.

if you using one of the OEM 5th/RS/Fox/manitou shock pumps with the 3" foldable hoses then on a pressure of 160psi in the boost valve chamber of a DHX5 a pressure drop os 40psi in normal whan reconecting the pump.

longer hose (or emty space) the greater the presure drop.

But all this is hypothetical as jimbo-norco has not told us which DHX3 he is using or which air chamber it is if it is the DHX air.

jimbo-norco

Sorry I forgot to mention, its the coil over type, with the chamber at the top, with the pro-pedal already set, and I use a wrench force shock pump with a flexible tube

nicklouse

so a drop of 50 could be possible as the air leves the chamber to prssure ise the pump.

set the pressure now. discontect the pump. and now check the pressure by reattching the pump. and the loss is?

you are not losing air it is just the pump equailizing the presure.

jimbo-norco

Its pouring down now so ill do it first thing, but if this is the case, how do I get the pressure to stay at what I want it at? because if I set it at 130psi which I like, its obviously going to drop when I disconnect the pump, and ill end up with about 100psi, and the back will be too soft?

nicklouse

No. set it to 130 and that is it. it is set at 130. the air you hear is just from the pump.

jimbo-norco

so why is it that when I set it at a pressure, the next time I check it it has dropped? Im confused now :?

nicklouse

have you read anything? it has not dropped you have to fill the pump again.

like i said set the pressure. remove pump. re attach pump you can hear it re filling the pump and the pressure drops.

re set pressure and repeat and repeat and you will see that the pressure drop is allways the same.

now you kneed to know what this drop is so you can see if the pressure has actually dropped when you check it at any other time with that pump. NOTE that different pumps will give differernt "losses" if thier volume is not the same.