A motorcycle parked in front of a tent on a pleasant green campsite

Home Repair And Restoration

Fork Seal Fix

Job Date 23 February 2023

By Ren Withnell

The brave among you may remember my CB500X Fork Noise debacle. One of the suggestions for fork noise is stiction - where the fork stanchions are not sliding up and down smoothly in the tubes. "Put some grease around the seals" was one suggestion. By that point I was ready to try anything and anyhow, what harm can it do?

The grease did not fix the fork noise issue, but now the issue is fixed (click here) I have leaking fork seal. Poop.

But - why would grease cause the fork seals to leak? Is there a possibility the grease attacked the rubber? Nah, it's common or garden grease that I'd use on wheel bearing seals and I wouldn't concern myself if some got on an o-ring. No. I suppose it's just one of them things. Bad timing. Unlucky. I suppose I'll do some googling around to see what needs to be done to replace the seals.  

While trawling between heated arguments over what kind of oil you should use inside the fork I saw a suggestion. There's a thing called a "seal doctor". The theory is most leaky fork seals are NOT caused by old, dried up seals, particularly on new motorcycles, most leaks are due to dirt between the seals and the chrome stanchion allowing oil past the seal.

Hmmmm. Makes sense. The bike is only 5 years old and 27,000 miles. Plus I've been messing with the forks a lot. Maybe, right, yeah, OK, maybe that grease caught some dirt and brought it down into the seals? So how much is this "seal doctor"?

Wait a minute, another forum poster says I can make my own seal doctor. I need the lid off a margarine tub and a pair of scissors. I duly rip the lid off my margarine tub (I'll worry about how to keep the dirt out later) and grab the scissors. Some 60 seconds later I have myself a DIY home made seal cleaning implement. This is the MLBSCT (Margarine Lid Based Seal Cleaning Tool)

A section from the lid of a margarine tub cut into kind of a rounded "L" shape
Such skills, such craftmanship!

Outside in the shed I pull back the dust covers and spend 20 minutes cleaning away all the grease and dirt between the dust cover and the seal and the fork leg. I push the MLBSCT gingerly into the seal - it slides in, I sweep it around a little and I pull it out. Oooh dirt!. I wipe the MLBSCT and repeat, moving around the seal slowly and carefully, pulling out more muck. 

Ren's hand is carefully slipping the thin sliver of plastic into the fork seals
Slide the MLBSCT between the stanchion and the seal and rotate a little.
We see the sliver of plastic between the seal and the chrome
Just there, between the shiny bit and the rubbery bit.

Be careful Ren. The very thin but stiff plastic of the margarine lid is the very best plastic I can imagine for this job - but - it is thin enough to slice into the seal if I get the angles all wrong. I take my time, carefully sliding the MLBSCT in, moving it around say 50 or 60 degrees, pulling it out an wiping off the dirt.

After 10 minutes the MLBSCT is coming out clean. I replace the dust seals and wait for the next ride. Woohoo! Success. After 200 miles over the weekend my forks have remained dry. I wonder just how many times fork seals have been replaced when all that was needed was a clean?  

Will this always work? No, definitely not. Seals get old. Seals wear out. Seals get torn. Cleaning a damaged and/or old seal will not fix your problem. But for the sake of a margarine tub lid it's worth a shot ain't it? Now - what am I going to cover the remaining margarine up with?

Share your tips - click here.

Reader's Comments

Upt'North ¹ said :-
Ed, you're a genuine genius. Or......has all the oil already leaked out?
No, you're a genius.
05/03/2023 23:36:57 UTC
Bogger said :-
You could start another, much more successful, website site called:-

'Bodgery and Fertling for Really, Really, Tight People'.

I think you'd need to put in some sort of disclaimer to stop any litigation issues. I know you don't want to be paying for any Lawers fees.


06/03/2023 13:09:49 UTC
Ren - The Ed¹ said :-
I am a genius Upt', I'm sure if it. I'm just such a genius I'm misunderstood - see Bogger's comment.

While this blog is called "Bikes And Travels" Bogger you and I know it is actually all about the random antics of one man's mission to spend as little as humanly possible. This is my struggle, this is my fight. All around people tell me to "enjoy myself" and "live a little", even my partner Sharon would like to see my wallet crack open once in a while. You all think life is about "having fun" and "being happy"! Frivolous and extravagant nonsense. You're here for a long time not a good time.

Speaking of which, I must darken your doorstep soon once more Bogger - you have been without my miserable face and depressing demeanour for far too long.
06/03/2023 17:15:44 UTC
nab301 said :-
Nice fix Ren , a friend did something similar recently and reported similar results.... so far!
I am surprised that you had your own margarine lid , I thought it was dry bread and stale cheese for you ?
07/03/2023 23:58:25 UTC
Bogger said :-
Ren, I have recently installed a drawbridge and Port Cullis onto Bogger Towers.

Thinking about it you are the British version of ICHIBAN MOTO.

08/03/2023 12:16:38 UTC
Ren - The Ed¹ said :-
Stale cheese! LUXURY I tell ya, luxury. When I wur a lad we used to dream of stale cheese (etc etc etc etc...). The more astute among you will notice the lid if from an Aldi product. Mind you Aldi ain't so cheap no more.

ICHIBAN MOTO! Now where do you think he gets all his skills, knowledge and ideas from Bogger? And you think fortifications will prevent me reaching my righteously deserved tea and biscuits?
08/03/2023 14:06:35 UTC

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