Should a coil shock (fox dhx) return (to full length)on its own?
without the spring on, that is, and the boost valve pressure let out?
Is the air assist the same as the ifp pressure?
therefore does it need the air assist pressure to return
Its a 2013 .5" shaft RC4
Should do, don’t compress it with the iFp pressure let out iFp is likely to burp into the oil. Which’ll mean it needs a bleed or rebuild
its a 2013 DHX RC4
IFp is air charged ( if piggy back has air valve)
If you repressuize and compress shock & is squelchy you have air in oil
on half rebound, theres a slight suction noise
rebound works
Hmm, hard to tell without seeing it.
They’re a due a full service every 200 hours/ 1 year according to Fox but every 18 months advisable so of not been done recently a full service is advisable
is there likely to be much else wrong with it?
it looks all good
Aside of damage to shaft, perished seals which would be sorted by service ( seals) not a lot else to go wrong.
The IFP pressure should extend the damper shaft.
Service instructions are on the Fox website if you want to see whats inside it
https://www.ridefox.com/fox17/help.php?m=bike&id=192
Normal setup instructions (they explain air assist, air assist volume)
https://www.ridefox.com/fox17/help.php?m=bike&id=70
thanx for yr help
I dont suppose that if there is air in the oil, then it would alter the IFP heightsufficiently to notice the difference?
Depends how much air, it’d need a fair bit.
Main issue is the effect on the damping as it will become inconsistant as the shock is worked heat rises.
Sorry, I was not clear, on a DHX RC4 the air assist chamber you inflate with a standard shock pump is the IFP chamber, should be 160 psi.
Have you checked the pressure?