Replacing Fork Seals - woodscrew technique or full strip?

[Ted]

I'm editing this rather than starting a new thread on the same topic!

My bike failed it's MoT test, one fail point was a weeping fork seal.

At some point in the past I remember changing fork seals on a bike from the top of the fork, removing the dust cover, sticking a wood screw in, and pulling the oil seal out. After some internet searching today I think this is just referred to as the 'woodscrew technique'. However not many seem aware of it, and fewer seem to have done it.

So my modified question is a non-model specific one; who has changed seals this way, and is it worthwhile or am I best just dismantling the forks completely?



--- original message ---
I've had a look in the Haynes manual, but I can't find a section on changing fork seals, only stripping and rebuilding the forks.

Can I change the fork (oil) seals on a 2007 CBF500 from the top, or do I have to fully dismantle the forks?

[Stalk]

I've done my divvy from the top a few times.

[Ted]

I might give it a crack from the top then. I know I've done it on something in the past, can't remember what though!

[Ted]

I've edited the original post, this method of fork oil seal replacement seems less common than I expected!

[Nobby the Bastard]

[andym]

On all the bikes I've done I've just removed the front end, put a flat bladed screwdriver through the seal and removed them, tipped the forks up side down to remove the oil then used a measuring tape to refill the oil to the required height.... and never had a problem doing it that way yet

[Rogerborg]

Do you want to change the seals?

If you don't particularly want to, then take a thin piece of stiff plastic (a sliver of Irn Bru plastic bottle works best) shove it down under the seal, then wiggle it up and down and all the way around.

Bounce the forks, see if it's still leaking.

If it is, then you've wasted 5 minutes less the time it would take to type "Bah, I'm not wasting my time, that will never work, besides even if it did it would just be just a temporary bodge, you get what you pay for, a stitch in time saves nine, loose lips sink ships."

If it works, you can thank stinkwheel for suggesting it. I have, repeatedly, since this has worked for me on multiple forks on multiple bikes.
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[Ted]

I don't really want to change them. Only one is seeping, but I assume they are a 'replace in pairs' thing? I wasn't even going to bother changing fork oil.

I've owned the bike for probably a couple of months, done maybe 300-400 miles, and a good chunk of that was going to a bike show.

I have two options:

a) quick fixes, get it in for the partial re-test

b) take it off the road over winter, go over it properly, rebuild forks, clean it all up, take tank and panels off and try to sort out the paint job.

[Rogerborg]

You could have tried the plastic in the time it took you to write that, and to read this, and to reply with why you don't think it'll work.
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[NeverAgain]

[Ted]

[Skudd]

I have a special tool for removing seals, just whack it in and pull the seal out. I've used it loads of times. I do have one fork that always seems to weep no matter what seal I put in it.
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[kramdra]

In my experience fork seals are a tight fit and wont be coming out so easily, they atleast need a bit of heat, which can cook the bushes. I avoided it on the cbr6 about 30000 miles ago and it has not returned.

Cleaning the seals/sealmate is a good idea but will not fix weeping seals. A big squirt of grease on the fork before the dust seal, this will fix it.

[Teflon-Mike]

The pop bottle scraper 'trick' only works if the seal isn't donald-ducked to start with, and the weep is merely trapped crap under the seal lip.. which has to go some-where, when you wedge pop-bottle plastic into the gap to un-trap it... usually into the oil beneath to scratch the forks and chew the seal some more... it's worth a try, but it's no substitute either for a proper seal replacement nor for cleaning your damn forks from time to time!

Woodscrew trick.... you have to drop the forks to get the new seal in anyway... if not get the old one off, if you dont want to be faffing about trying to cut it... and there's usually a steel washer bedded into the rubber at the top of the seal to make it rather awkward to get a wood-screw into.... often needs a small pilot hole drilling into the seal to give you a chance to get it to grip... and all told likelihood is that it makes the job no 'easier' and gives you a heck of a lot more chances to eff something up and do damage to soft and expensive aluminum, or ding even more expensive hard-chrome plating to chew up any new seals you do get 'in'.

Doing the job 'properly' (on Right-Way-Up-Forks) is no huge hassle... you pull the front axle,drop the wheel and take out a leg at a time, and if you have popped the brake caliper, first its a doddle...

IF there's a 'trick' it's to leave the fork clamped in the yoke, until you have pulled the wheel and axle; THEN you tackle the most awkward bit, which is usually the damper bolt accessed from the bottom of the fork with a long allen key.... Hint... they are usually full of crud cos no-one cleans forks... so clean well first, and use something pokeyto get the crud well out the way before you start trying to wedge allen keys in there.

A 'long' allen key is normally needed to get past the axle boss, which usually means a real allen key, not an allen socket.... and a spanner on the short end of the allen key to give it a bit of extra leverage.... a ball-end allen key wont give best purchase on the allen bolt and under big torque likely to be applied can more easily chew the head... use a plain allen, and make sure its well into the head of the bolt.

With the damper bolt dropped, THEN you can remove the stanchion cap, releasing the tension of the main-spring, which you needed to keep the pressure on the damper rod and stop it turning when you undid the allen bolt....

And then the leg removed from the Yokes and the oil drained and the slider dropped from the stanchion, the oil poured out, saig fighting with the drain screw and risk rounding the head or stripping the head of that.... and with dust cap removed from leg, the upper gubbis ad circlips ga be removed from above the seal, which IF the thing would respond to a woodscrew attack, will probably drop out when you pull the stanchion from the slider anyway! If not, the expensive bit, the hard chomed stachion is out of harms way and can be inspected to see if its dinged, chewed or rusted to cause seals to fail, or good enough to re-use... whilsy you have full access to get the seal out without the tube the way of even seeing rusty circlips holding it in, and gan get at the damg thing with 'apropriate instrument' to get it out... BFORE cleaning up the housing to take a ew one, so that that one has best chance of sealing and not succombing to premature fail either....

All up? As my Granny used to say so often, "Lazy-Man's Way is usually the longest... do it propper....it'll be quicker in the long run"... which given how un-oneruse a fork seal is more often true than not.... do right do once sort of thinking.

Biggest hassle is a long enough allen key for the damper bolt, and propping the bike up so it don't topple whilst you tackle it.. this IS to my mind one of the LEAST scary/difficult/annoying jobs there is on a motorbike! Bit a little patience and a lot of attention to detail and CLEANING is the key.
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[Ted]

I'm not scared about doing the job, I just know it'll be a pain.

I'll have to do it in the back of my van, which means not much room to move. It's also the type of thing where I know I'll forget one tool, and have to go all the way back to my lockup to get it. It's this type of job that usually takes several hours.

I've also only got 1 week to get it in for the retest, considering I've not even had time to go near it with a bit of a plastic bottle, I'm unsure if I've got the time to mess around stripping forks down..

[Ted]

Had a few minutes to try the drinks bottle idea.

Popped dust cover off. Did a double take.

...When did Honda start fitting toilet paper between the oil seal and the dust cover?



Forks will be stripped down I guess.

Best order some oil and dust covers. What's the chances I need new bushes on a 10 year old bike, with 60k miles on the clock?

[tom_e]

[Ted]

[Qyburn]

Agree. Wear in the bushes means the seals have a harder job, which could mean the new ones failing sooner.

If it's a very slow weep, how about just changing the toilet paper (after cleaning the recess right out of course)?
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[Ted]

I'm all for a bodge, but loo roll is a step too far.

It is only weeping, but it must have been bad enough for a previous owner to try and hide. So there is every chance I'm low on oil too.

[Stalk]

Undo the spring cap, remove spring and spacers, drop out fork leg. Push upper as far as it will go into lower to minimize damaging the swept area, and remove seal. There will probably be a spring clip holding the seal in. Gently and evenly drift new seal in. If you can find a bit of pipe the right size its a bonus. Refit and top up oil. Before you start, pop out the dust seal and assess the spring clip, if its corroded it will pay to order a new one before you start. Bit of tape around the sharp end of the leg before slipping the seal over will save cutting the seal lip. Should be able to do this in about an hour. If it works, happy days! If not, you haven't really lost anything

[A100man]

Gaitors..
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[sickpup]

[Tankie]

Yep, that's the proper way to do it, impact driver and hex bit.
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[Ted]

I've got an impact wrench (electric one), but where I'll be doing the work has no power.

I might go with the semi-strip idea, I've ordered new dust caps as one is damaged, and will grab some oil from Halfrauds.