Dark oil (damper?) in Fox fork

A five year old damper that hasn't been serviced?
It's time.

Oil degrades and darkens with use. Totally normal with lots of use.

Clean it all out and start again.

derp, yeah, I should have just started with "this thing has had the piss ridden out of it and a neglected damper."
follow up questions:

1. how do I know if it needs to be bled, or rebuilt?
2. can I trust myself to DIY either of those jobs? I guess that's a personal question.
3. considering the cost of the tools involved and questionable overall condition, should I seek out a deal on a Grip2 damper or some alternative?

Go just halfway down the page until you see the header Ford Damper Cartridge Service. Not sure which Fit4 you have but the manual and pictures will give you an idea of what you're in for.

Christopher Robin said:

Bike Help Center | FOX

www.ridefox.com

Go just halfway down the page until you see the header Ford Damper Cartridge Service. Not sure which Fit4 you have but the manual and pictures will give you an idea of what you're in for.

Click to expand...

I was reviewing those procedures and the main problem is that I need about $200 in tools for a job I will do so very rarely, plus a blowtorch! I can't justify that purchase. the job also looks very intimidating. I build wheels and do basic lowers maintenance on my own with no problem. I also can't find a mechanic nearby who will touch it. unless I find someone willing to do the job — the parts kit is only $25 — I'll try bleeding it to get a few more rides out of it until it needs more attention.

Which is why you usually have to send the damper or the whole fork to your nearest Fox service center. Some shops can do it if they have their own little suspension service desk, but I guess that depends on how big they are.

The fork was 140mm when I got it, and the seller gave me a 130mm air shaft. I ended up dropping it to 120mm after a few rides. however, I am looking around at replacement damper assemblies and some are listed for 130–160mm forks at some online retailers. no mention of the damper assembly designed for 120. I did this probably two years ago, but I remember asking around to see if I needed to change anything else when lowering the fork travel. is it possible that I made my fork too short for my damper, and that might lead to more trouble down the road?

mack_turtle said:

it possible that I made my fork too short for my damper, and that might lead to more trouble down the road?

Click to expand...

no

mack_turtle said:

derp, yeah, I should have just started with "this thing has had the piss ridden out of it and a neglected damper."
follow up questions:

1. how do I know if it needs to be bled, or rebuilt?
2. can I trust myself to DIY either of those jobs? I guess that's a personal question.
3. considering the cost of the tools involved and questionable overall condition, should I seek out a deal on a Grip2 damper or some alternative?

Click to expand...

1. If your damper is slurpy, leaking or has a swollen bladder then it needs serviced. Otherwise go on time and riding.
2. Depends on your.
3. Grip2 stock is nothing special. I'd get Vorsprung Tractive put into a FIT4 long before fitting GRIP2.

assuming this does not cost half of what a new fork might cost me, I'm dropping this off at a shop today. that's the first time I've had to do that since I was... 14? I found a few shops who can do the work in-house. I like to work on my own bike, but I draw the line at $200 in special tools that I'll use once, and the fact that I need to take a blowtorch to my bike to complete the job.

mack_turtle said:

assuming this does not cost half of what a new fork might cost me, I'm dropping this off at a shop today. that's the first time I've had to do that since I was... 14? I found a few shops who can do the work in-house. I like to work on my own bike, but I draw the line at $200 in special tools that I'll use once, and the fact that I need to take a blowtorch to my bike to complete the job.

Click to expand...

Can the shop do Vorsprung Fractive? It's the same labour to install that as to service a FIT4. Just a bit more time to pick out a tune.
It will turn the FIT4 from something average into something excellent.

who here has performed this service at home? I don't have any of those proprietary tools, and I might DIY it if I can buy the tools at a cost that makes it worthwhile. I see some alternatives to the rod clamp for $25-30 on Etsy and Ebay instead of the $100+ unit from Fox. do I need those "bullet" tools, or do those just make assembly easier? the instructions look intimidating, but if all I need is a shaft clamp, bleed syringe, and a rebuild kit, I might dive in on my own. I have a table vice, torque wrenches, and all the other standard tools that I can imagine.
edit: nope, that process looks frustrating. if I owned more than one mountain bike and could be patient with fixing this one while I take my sweet time doing this, perhaps. every day that I spend with this fork not working is a day I spend not riding.

mack_turtle said:

who here has performed this service at home? I don't have any of those proprietary tools, and I might DIY it if I can buy the tools at a cost that makes it worthwhile. I see some alternatives to the rod clamp for $25-30 on Etsy and Ebay instead of the $100+ unit from Fox. do I need those "bullet" tools, or do those just make assembly easier? the instructions look intimidating, but if all I need is a shaft clamp, bleed syringe, and a rebuild kit, I might dive in on my own. I have a table vice, torque wrenches, and all the other standard tools that I can imagine.
edit: nope, that process looks frustrating. if I owned more than one mountain bike and could be patient with fixing this one while I take my sweet time doing this, perhaps. every day that I spend with this fork not working is a day I spend not riding.

Click to expand...

Have you removed the damper from the fork? If it is still functional and the bladder hasn't ruptured you will be ok just to basically just remove the sealhead and bleed/LSC screw (careful with the circlip!) flush out the internals with cleaner and reassemble.

If the bladder is so swollen it won't slide out of the stanchion easy, or the oil inside the damper is super dirty then it would be best to replace the seals but even then you could do a really good clean and bleed to keep it going until you have some more time.

For that you only really need the body clamps (17ish mm) and bleed syringe.

Damaged bladder or other potential wear/issues - take it to a pro

You probably won't need a blowtorch but a heat gun will substitute fine as well. If you don't have a heat gun either you need to buy one!!

mack_turtle said:

who here has performed this service at home? I don't have any of those proprietary tools, and I might DIY it if I can buy the tools at a cost that makes it worthwhile. I see some alternatives to the rod clamp for $25-30 on Etsy and Ebay instead of the $100+ unit from Fox. do I need those "bullet" tools, or do those just make assembly easier? the instructions look intimidating, but if all I need is a shaft clamp, bleed syringe, and a rebuild kit, I might dive in on my own. I have a table vice, torque wrenches, and all the other standard tools that I can imagine.
edit: nope, that process looks frustrating. if I owned more than one mountain bike and could be patient with fixing this one while I take my sweet time doing this, perhaps. every day that I spend with this fork not working is a day I spend not riding.

Click to expand...

Do what JohnnyC7 said. I’ve bled one and it’s not difficult, just some patience. Although I chose the wrong diameter tube at first and frayed the o-ring that seals inside the LSC adjuster but that’s another story and it shouldn’t happen to you.

You don’t need special tools to bleed it, only a syringe with a plastic tube and damper oil. Start from step 38 in Fox’s instructions. And put your thumb on that circlip!

My concern with just a bleed is that it's currently leaking fluid into the lowers. If there's a worn out seal somewhere, a bleed won't help that, right? It would still need to be torn down and replaced.

mack_turtle said:

My concern with just a bleed is that it's currently leaking fluid into the lowers. If there's a worn out seal somewhere, a bleed won't help that, right? It would still need to be torn down and replaced.

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Thats why I asked if you have removed the damper, if the bladder is very sucked in and feels very aerated then it has probably leaked. If it seems relatively normal then its fine.

The extra oil that dripped out was possibly just what was clinging to the inside of the stanchion, which can take a few minutes to fully run out

I would advise that you do a full service - including the replacement of the sealhead, as it has probably worn out the seal and will ingest more bath oil as it works.

Stefan

Oil volume wise that bladder looks perfect, at full extension it’s “relaxed” ie not sucked in or bulging at all.
Damper seal heads will always gradually ingest oil, Fox forks normally take a long time though. Depends on use, frequency of services and type of oil used.

personally I wouldn’t worry about trying to change the seal head yourself, in all honesty they are so reliable you are more likely to cause a leak than prevent one