[hmcleay]

Hi guys,
I'm in the middle of servicing my DHX 4.0 and really need to get into the pro pedal (effectively LSC) part of the shock. to do this i need to unscrew the 'air canister' from the main body (black part) of the shock.
my main problem is that i can not get enough grip on the air canister to unscrew it. i have special wooden blocks that i use to hold the shock in a vice, but even these can't hold it without slipping.

does anybody know of a trick to get this canister off? i have tried everything except a pipe wrench... which i'm not going to use, unless it involves smashing the sh*t out of it through frustration

is it definitely a right hand thread?
btw, i have taken the rest of the shock apart. i.e. schraeder valve has been removed, internal floating piston (IFP) has been removed.

i realise that these shocks are supposed to be sent away for a 'professional' service, but i enjoy doing these things myself and i'm usually pretty good at it.

Cheers,
Hugh

 

[davep]

There is no air canister on a coil shock.

What exactly are you trying to do?????

 

[hmcleay]

By 'air canister' i am referring the cylindical shaped object biggy-backed off the main body of the shock.
the dimensions are approximately 30mm diameter x 50mm long.
i have termed it the 'air canister' because it has a schraeder valve in it and it should be pumped up with air to approx 80-120psi.

my pro pedal is not working properly and i am opening it up to inspect the threads on the adjuster shaft (which preload a spring onto the shim stack).

 

[DownCycles_Stef]

Well not to get into a tech-jargon fight here, you're referring to the reservoir. To get access to the part which you are looking to access, it's probably easier to start removing from the end of the reservoir that is opposite the pro-pedal knob. That being said, if you really don't know EXACTLY what you are doing with the shock, DON'T OPEN IT! If you feel something may be wrong with the way the Pro-Pedal is operating, contact Fox and it should be covered under warranty, assuming it's not rider error.

Since I get the feeling you probably don't want to do that though, what exactly do you mean when you say it isn't working properly? What isn't it doing that you want it to, or what WAS it doing that it isn't anymore?

 

[Curious_George]

sounds like the piggy back

 

[MobileChernobyl]

Haha DownCycles_Stef lay off the dude, I'm not sure if you've done this yourself (if you had, you probly would of offered advice) but it is tricky, as I was in the same situation as the OP a few months ago, doing the same modification to the LSC probably.

I tried a strap wrench (it broke lol), but be warned, ANY method of applying pressure to the outside walls of the resevoir should be done WITH the air cap ON!! haha otherwise you can easily crush that almost paper thin tube pretty easily with just the right amount of outside pressure.

Heres my personal method for doing what your trying to do:

Step 1: thread the air cap back on snuggly
Step 2: Fabricate a sort of rubber jaw'ed addition to any adjustable wrench (monkey/pipe, or channel locks/crescent wrench) that will fit the OD of the resevoir pretty well.
Step 3: Grab the resevoir at the TOP essentially OVER THE THREADS of the air cap. this way you will transfer the pressure through the thin walls of the resevoir into essentially a solid member, but still have a grip on the resevoir body.
Step 4: Unscrew (im like 99% sure its regular thread, but don't quote me, you pretty much would have to have the torque of a cummins diesel to strip it out anyways)

You will also need a circlip tool to remove the c-clip holding the LSC valve in.

 

[Pat Tellier]

You might want to heat the joint before trying to unscrew the reservoir. It is usually assembled using permanent thread-locking fluid (red Loctite) at the factory.

Then use a rubber-band type pipe wrench (as used on cars to remove the oil filter). You can probably buy that tool in a 1$ store.

Make sure you also re-assemble the reservoir using the same thread-locking fluid, otherwise the pressure will make it become loose.

Also, pay special attention to the position of the floating piston in the reservoir when you refill with oil. The position will affect the progressivity of the shock. I don't know the position for the DHX 4 but you can probably find it somewhere on the net.

 

[DownCycles_Stef]

I wasn't trying to be rough on anyone MC. There have just been a number of people on here and other sites which have gotten themselves in too deep when working on shocks and ended up having to drop cash to fix it. I love tinkering with my own crap as well, and now that I'm running a Vivid on my race rig, I'll almost certainly be working on it. That being said, I prefer to give safe advice because in the past when I have suggested ways to do more complex work by yourself to customers and people online, I have ended up being screamed at and told I am responsible (in the shop setting). In fact I have personally ended up paying for repairs directly out of my own paycheck when customers at my shop have tried to fix something then failed & broke equipment even after I HAD warned them to be careful and not do it unless they were completely confident and willing to accept the consequences.

In short, I guess people in general need to start being more willing to accept the results of their actions. And I'm sure no one on here would hold me liable for advice I've given, but until I can be completely positive that that is the case, you'll only see me giving out "safe" advice. Sorry.

-Stef

 

[Bati]

I made this tool to grab the main body of the DHX (dia 31,8mm). You can use a tee too, but the tool is a little more polite.



You can do the same tool but with a 30,5mm diameter for the reservoir.