Fork/shock experts - advice please

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Fork/shock experts - advice please

21 posts & 8 voices | Started 6 months ago by perthmtb | Latest reply from phiiiiil

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perthmtb - Member

New bike. I'm no expert on suspension, but I've noticed a problem with both the forks and rear shocks that I'm sure shouldn't be happening...

1. Forks (Fox 32 F125 RL)- after putting a little air in, and letting some out, when I unscrew the shock pump off the valve there's blue/green oily liquid filling the internals of the schrader valve. I did have the bike upside down for a while before this, but surely there shouldn't be any oil/fluid in the air spring that could leak out through the valve - is there?

2. Rear shock (Fox Float R) The pin of the schrareder valve is recessed too far into the barrel of the valve. So when I screw the shock pump on it doesn't depress it and allow me to pump air in, or release any out by pressing the button on the pump. If I press hard on the pump plunger it does build up enough pressure on the valve to open it for a short duration with a 'click' for the air to go in, but then closes again and only way I can release air is by removing pump & pressing valve pin manually.

Before anybody asks, yes its a new bike and these are obviously warranty issues, but before I tackle the shop I'd like to be properly prepared, as the guys have been known to try and BS their way out of warranty issues before!

Thanks.

Posted 6 months ago #
phiiiiil - Member

(1) is sort of normal... there should be some lubricating oil in the air side, and some will inevitably come out when letting any air out. It shouldn't be much, though, but it might just be a combination of having had the bike upside down previously and possibly having slightly more oil than necessary. Better too much oil in than not enough, though, which seems to be how they normally are when new...

(2) I'm not sure about, but even if the pump doesn't push down the plunger should the air pressure from the pump not do it anyway? Is the plunger stiff? Could it be that the valve core is screwed too far in or somesuch?

Posted 6 months ago #
coatesy - Member

The oily liquid's normal if you've had the fork upside down, there's a small amount of lube inside the uppers, some of it will escape through the valve when you open it.As for the pump, not sure, but had a similar problem with a Fox TALAS years ago, could pump it with a Marzocchi pump, but not one of Fox's.

Posted 6 months ago #
perthmtb - Member

Hi Phiiiiil, thanks for the advice.

1. After doing it twice, there doesn't seem to be any more coming out, and fork operation seems normal in all other respects. So, if you say its normal to have a bit of lube in the air side, then maybe this was all it was - phew!

2. Yes, the air pressure will push it down, but then it pops up again, so the guage is reading the pressure in the pump chamber rather than in the shock, and when you press the button on the shock pump to release some air, again, the chamber in the pump empties but not the shock. I think you hit the nail on the head, the valve core is screwed in too far, but no idea if this is a simple job to adjust. I tried taking an inner tube scraeder valve apart to see if this offered any hints. Seems that needs to be screwed all the way down for seals to seat, so height of pin not really adjustable. Is the schraeder valve in a shock the same, or can the height of pin be adjusted - I just don't know, and as its new, don't really want to go in there poking around to find out! If so, hopefully the guys in the shop can adjust it and I'll be on my way again quickly - otherwise they'll be sending it away for warranty repair - and that means no new bike for a few weeks at least!

Posted 6 months ago #
perthmtb - Member

Hi Coatesy, thats good, looks like no 1 is turning out to be a non issue - breathes large sigh of relief - I hate the hassle of warranty repairs!

On 2, I've tried another shock pump and same issue. Maybe there's a make out there that extends further into the valve, but it really outta work with any shock pump right?

Anyway, thanks for the replies guys, keep em coming - I was real depressed when I thought my shiny new purchase was a dud, but the shared therapy room of STW is working wonders....

Posted 6 months ago #
mttm - Member

1. As has been said, this is normal - there is 5cc of Float Fluid (a heavy blue coloured oil) on top of the air piston to lube the seals.

2. Sounds like the valve core has been tightened too far. Carefully blow off the shocck air pressure and then remove the valve core (you need an extractor, any motor spares shop will sell you one). Reinstall the valve core and just nip it up - it doesn't need to be done up with a scaffold bar. This should sort it.

Posted 6 months ago #
perthmtb - Member

Thanks mttm, looks like we're knocked No 1 on the head, and closing in on the problem with No 2.

I managed to unscrew the valve core on an old schraeder tube with the help of a teeny pair of needle nosed pliers. The one on the shock is deeper in, so that won't work. Anyway, I'm thinking at this point having identified the issue, maybe its best to let the shop sort it, as it is a brand new bike, and I don't want to do any damage inadvertently by poking around in there. What dya think?

Posted 6 months ago #
perthmtb - Member

mttm, just re-read your post...

there is 5cc of Float Fluid (a heavy blue coloured oil) on top of the air piston to lube the seals.

But should this be able to escape through the air fill valve? Thought the air 'bag' would be sealed from the seal lube?

Posted 6 months ago #
retro83 - Member

But should this be able to escape through the air fill valve? Thought the air 'bag' would be sealed from the seal lube?

It's oil inside the stanchion, to lube the o-rings which make up the air spring. There is no 'bag'

Posted 6 months ago #
perthmtb - Member

Ok, I'm getting there... Good picture, made things a lot clearer.

So, No 1 no longer an issue.

As for No 2 I'll try and pick up a valve core extractor, but if that doesn't fix it or I get in out of my depth, It'll be back to the shop on Monday.

Thanks all - what a great resource STW is!

Posted 6 months ago #
landcruiser - Member

Let the bike shop sort it out.... If you accidentally break something this will most likely cease to be become a warranty issue and you could be charged for any repair.

Posted 6 months ago #
perthmtb - Member

Landcruiser, you speak wise words. I'm always tempted to have a go myself, and thats how I've learnt to do most things on a bike - but I should try and resist that temptation when its brand new and could be a warranty issue...

Posted 6 months ago #
perthmtb - Member

Despite what I said above about not fiddling - I couldn't resist it , and today bought the tool from the local car accessory shop and took the valve core out.

Replaced it with a 'new' one from a spare inner tube valve, and hey presto problem fixed!

Funny, cos the two valve cores look identical, but for some reason the original one screws further into the valve so the pin is just out of reach of the pump, whereas the 'new' one sits a few mm further out

So, thanks all for your advice and patience - but one last question if I may... is there any reason I shouldn't just leave this 'new' valve core in and get on riding? Specifically, is there anything special about the one that came with the shock, or is a schraeder valve core just a schraeder valve core, whether its on an expensive shock, a truck tyre, or a bike inner tube? I'm thinking pressure ratings, compatibility of rubber seals with lube - that kind of thing.

Thanks.

Posted 6 months ago #
khani - Member

Ooooh! It'll explode and kill everyone if it's not a genuine manufacturers rear shock valve core..!!!!!!!
Or maybe not....it'll be fine, I done it to my RP2 over a year ago and I'm not dead yet!

Posted 6 months ago #
perthmtb - Member

LOL khani - yes I know I'm probably over thinking the potential issues, but its also a warranty thing - it is a brand new bike afterall, and I don't want to invalidate the warranty by putting a sub-standard part in there!

Posted 6 months ago #
takisawa2 - Member

Rigid 29er will solve all of the above.

Posted 6 months ago #
khani - Member

I used one out of an innertube, it looked identical to the one in the shock and been good for twelve months so far
Stop thinking and go ride enjoy your new bike...

Posted 6 months ago #
khani - Member

Rigid 29er will solve all of the above.

'yes'' yes it will.....but your bones will crumble like custard powder instead...!!!!

Posted 6 months ago #
perthmtb - Member

+1 to Khani. The reason I just bought a FS bike is cos I did a four day MTB event last month on my hardtail (tho' not a 29er) and promised my body I'd never put it through that again!

Posted 6 months ago #
perthmtb - Member

Quick update for anyone searching in the archives...

Emailed Fox in the US and they replied that the core of the air fill valve is just a standard schrader valve core, and one from an inner tube or auto parts store will do just fine.

Posted 6 months ago #
phiiiiil - Member

I love it when a plan comes together!

Posted 6 months ago #