Topic: Who has had success cleaning fork seals? (Updated)

[ChuckG750f1]

My right side fork seal was leaking pretty bad.  Before tearing my forks apart, I decided to give the "cleaning with a piece of plastic trick" a try.  Now it's like new.  Makes me wonder how many seals have been changed because of some crap between the seal and the tube.

[Tugboat]

What did you use?

[ChuckG750f1]

What did you use?

I cut a 3"X 1.5" piece out of a "blister pack" that a set of grips came in.  I used that because the curve in the plastic seemed like it would want to follow the radius of the inner seal/tube interface.  I cut a soft curved "hook" shape in the leading edge of the plastic that I dragged around between the seal and tube.

[Duke McDukiedook]

If the seal is original to the bike you are usually just better off replacing it, rubber gets brittle over time and need replacing.

[cmonSTART]

Interesting.  Have you put any miles on it yet?

[Tim2005]

I do a lot of off-roading and have done this successfully for years. I use a 0.1mm feeler guage for it. I haven't had the need to try it on my sohc but I'm sure this would work if dirt behind the seal is causing a leak.

[ChuckG750f1]

If the seal is original to the bike you are usually just better off replacing it, rubber gets brittle over time and need replacing.

I don't know how old the seals are.  They don't have the look of 34 year old seals but I have nothing to compare to except the new ones from Vintage CB750 and they look identical.  I pumped the front end as hard as I could about 50 times and rode the bike about 10 miles on a nice switch back resulting in NO oil on either tube.  I'm going to keep a close eye on it and I have a new set of seals but I'm not going to do it unless it starts leaking again.  I'm curious if other's have tried this with success.  BTW, my fork tubes are in very good shape, no rust, chips or dents.

Thanks for your replies.

[robvangulik]

It is indeed quite a common practise with motocross and offroad riders to clean the seals with either feeler gauge or a piece of photofilm, what also often works is spraying the forkleg with siliconspray and pumping the forks a few times to flush any dirt away.

[ChuckG750f1]

It is indeed quite a common practise with motocross and offroad riders to clean the seals with either feeler gauge or a piece of photofilm, what also often works is spraying the forkleg with siliconspray and pumping the forks a few times to flush any dirt away.

Yeah, 35mm film is what I had heard about and was trying to copy with the blister pack plastic.  I just didn't know if this was hype or real and was surprised by the dramatic result.

[robvangulik]

So long as it's only dirt between seal and forkleg that causes the leak, any way to get that dirt out without destroying the seal is OK.
A damaged seal means end of story, new seal.

[ChuckG750f1]

A skeptical friend of mine suggested that the reason it stopped is because there is no fluid left in the fork.  I don't believe that because I caught it and dealt with it quickly (the fork also feels fine pushing on it and riding the bike).  Also, it went from bad to nothing like a switch.  Thanks for the input and I hope others have the same result I did.

[Duke McDukiedook]

If it leaked odds are you do not have the proper volume of fluid in your forks.

[ChuckG750f1]

If it leaked odds are you do not have the proper volume of fluid in your forks.

10-4

[m00ntan]

Thank you. 

Handlebar grips plastic, right? 

I will try this.  It sounds like a thirty minute job.  It's always better to tear forks down on my own schedule.

[Accolay]

Sounds like a cool stop-gap solution, but it's only about $15 dollars for seals at Honda, $8 aftermarket.... It doesn't really take that long to take the forks off does it?

[ChuckG750f1]

It's not about $ for me.  I have the new seals.  If someone is on an extended ride, a piece of plastic and 5 minutes on the side of the road might save a lot of grief.  YMMV

[70CB750]

Thanks for the tip, one day I may need it.

[m00ntan]

Maybe its' just me. 

If I take the forks off, I want to buy new tubes, fork ears, rubbers and polish the lowers, like, on my schedule.  I'm sick.

[FrankenFrankenstuff]

If the seal is original to the bike you are usually just better off replacing it, rubber gets brittle over time and need replacing.

+1 These are machines that hold our lives in their capabilities. For the record though...I have done the same thing but used brake fluid to make the seal 'grow' a bit. UG. I am a bad person for sharing that.

[Accolay]

It's not about $ for me.  I have the new seals.  If someone is on an extended ride, a piece of plastic and 5 minutes on the side of the road might save a lot of grief.  YMMV

True, but the old seals have lasted a long time...I doubt after replacement (and maintenance) I'd see them leaking any time soon.

[ChuckG750f1]

So, I have now done a bit over a hundred miles all on back roads since "cleaning" my leaking right fork seal.  Still no sign of further leaking! 

[Spanner 1]

Tried the 35mm film deal.... worked like a charm  .... just cut a 3in. piece of 35mm film , held it tight around the fork tube and after 2 or 3 attempts got it worked down into the seal. Pushed down while turning and then removed it. This seal was leaking badly before this 'cure' and has held-up thru' a 600 mile Relay weekend, dry    ( yes, there is the correct amount of fluid in the fork )..... thank you  OP for posting this fix....

[ChuckG750f1]

Tried the 35mm film deal.... worked like a charm  .... just cut a 3in. piece of 35mm film , held it tight around the fork tube and after 2 or 3 attempts got it worked down into the seal. Pushed down while turning and then removed it. This seal was leaking badly before this 'cure' and has held-up thru' a 600 mile Relay weekend, dry    ( yes, there is the correct amount of fluid in the fork )..... thank you  OP for posting this fix....

It is hard to believe until you do it and see the results.  Since 35 mm film has become a thing of the past for most, try any thin strip of plastic (plastic soda bottle).

[Jerry Rxman Griffin aka MuthaF'er]

Good trick.

My next question would be: has anyone tried a stop leak or high mileage oil in their forks to condition/soften  the seals?!? High mileage oil sure seems to help the valve stem seals in my 208,000 mile car. 

[ChuckG750f1]

Good trick.

My next question would be: has anyone tried a stop leak or high mileage oil in their forks to condition/soften  the seals?!? High mileage oil sure seems to help the valve stem seals in my 208,000 mile car.

I believe that this trick/remedy for leaking seals is forcing crud out from between an otherwise good seal and the fork tube.  The crud is providing a passage for the fluid to escape through.  I'm thinking that a bad seal needs to be changed but that a "dirty" seal can be cleaned (easily).  A fork fluid that revitalized seals would be a great product though.