Cleaning out forks without dissasembly.

[herulach]

Right, the fork oil in the fazer is getting changed this weekend, as I'm pretty confident it will never have been done.

So, I'd like to get all the slimey grey gunge out without disassembling the things (seals etc are all fine). Current plan is to fill with paraffin, pump it a few times then leave to dry out for a bit - is that going to work or does anyone have any better ideas?
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YBR 125>FZS600

[TUG]

remove the forks, undo the top, leave upside down, pump like a shotgun, leave again, fill to specified amount (personally i use an air gap tool as its more accurate) then refit top -> refit forks.
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Haz ER-5, innit!

[herulach]

[TUG]

Maybe but tbh the oil will have to be like 10 years or older to do that, I've changed loads of fork seals and have never seen that sort of stuff, the oil just goes thin and pisses out.
Paraffin is seriously unnecessary.
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Haz ER-5, innit!

[herulach]

[stinkwheel]

If I was going to flush them with anything, I'd use warmed up (so it's thin) cheap and cheerful engine oil. Asda do some seriously cheap stuff.

That said, the gunk looks horrible but it's just emulsified oil. If there were bits of muck in there then I'd give them a flush out but I've never seen the need to flush any yet.

ATF makes a good substitute for 10wt fork oil and is very long-lived, pressure stable and maintains it's viscosity over a wide temperature range.
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Raffles]

I'm part way through rebuilding the forks on my 30 year old Bultaco and I suspect that that they too have been neglected since birth. I used cellulose thinners to remove the gunge although that probably wouldn't be a good idea if you are wanting to re-use your existing seals.
Stinky's idea of using warmed engine oil sounds pretty good.
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A good loser will always be a loser.

[The Artist]

Fork oil is really thin anyway. I have never seen gunk. The thickest oil from forks I have seen was about the thickness of normal 10w40 engine oil.