CB600 F4 Hornet - Front fork leaking oil

[Blunet600]

Hi, i am after some advice and/or confirmation. I had an off on my hornet around 2 years ago just as covid hit. The side was all scratched and the mirrors and foot pegs broke but the bike came off well and seemingly had no major damage.
Fast forward 2 years and the left fork is leaking oil, so i get the seals changed and then about a year later they are leaking again. I get them changed again and the next day there is oil leaking out still... so the mechanic changes the seals again for me and said if it leaks again then he suspects it could be a damaged pipe.
( Could this have been from the off i had... i hit deck on a bend and the bike slid on its right side down the road)
The fork did start leaking again the next day, so i am now looking at getting a new pipe but wondered if anyone had any other suggestions or advice before i went and paid for a new pipe (which is not cheap).

Thanks for the time all. Any help or advice is appreciated.
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Honda - Power of Dreams - NSR 125R - Hornet 600

[Easy-X]

I would have thought if a stanchion was so bent oil was pissing out the handling would be off as well

How much is leaking out exactly? A picture would help if you can manage it.
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Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[Pete.]

Bent stanchions are easy to check, just roll them on a flat surface, or roll them together. If they are bent you will know it right away.

As for the seals, probably if they are leaking and there's no sign of scuffing on the chrome, then they were poorly installed.
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a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[Blunet600]

A lot comes out, after riding for 20 mins or so, the fork is wet all round with oil. The seals have been replaced now 3 times. by 2 different mechanics... i had thought the same that maybe it had been installed poorly but both are decent bike mechanics with a lot of experience. i havent taken the pipe out but given what you guys are saying i will take it the garage before i order a new one and see if they have any ideas. I cant say i have noticed the handling being noticeably off... other than my own anxiety on bends these days....

will get the covers off soon and get some photos.
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Honda - Power of Dreams - NSR 125R - Hornet 600

[stinkwheel]

If there's no visible surface damage and no visible bend, it's probably not the stanchion. Probably needs new bushings. if you've got play in the bushings, the seals will fail. I just routinely replace the bushings if a set of seals goes with no obvious cause.

Also my experience of aftermarket seals is very poor. I just buy honda seals now because the extra cost is worth not having to do them again a couple of months later.
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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.

[Robby]

[MCN]

Either, the seals are being damaged on install or the wrong seals for the cylinders, or s4ite quality/non-OEM.
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Disclaimer: The comments above may be predicted text and not necessarily the opinion of MCN.

[stinkwheel]

If it's on its third set of seals, I'd say that if the bushings weren't buggered to begin with or have already been replaced, they will be now. Either that or they didn't actually dismantle the forks to change them and as such the bushings haven't been checked.

I would also say that just because a job was done by a motorcycle mechanic, doesn't mean it was done properly...

When I did the forks on Mrs stinkwheels CBR600FY, which I imagine are a similar age and design to your ones, the bushings were in there tight. They actually over-rode one another on one fork leg and took me a very long time to remove. Both sets of bushings were damaged after removal anyway (even the one that came right apart) so I replaced them and used aftermarket seals, both of which leaked a few months later. I then fitted Honda seals which have been fine.
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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.

[Blunet600]

Thank you for all your help. I have ordered new bushings and seals direct from honda. Hopefully they can all be replaced properly and i can out on the bike again.
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Honda - Power of Dreams - NSR 125R - Hornet 600

[A100man]

to add.. I'd have thought most forks with accident damage will bend at teh yoke clamp leving the travle area unaffcted for teh most part..

Bushings seems the answer -not that I've got any experience in that - my GT250 doesn't appear to have any
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Now: A100, GT250A, XJ598, FZ750

Then: Fizz, RS200, KL250, XJ550, Laverda Alpina, XJ600, FZS600

[P.]

How are the bushes looking?

I stripped my CBF last weekend as one started to leak a fair bit and one of the bushes was....well, not in great nick. Think its teflon or similar? It was basically gone around 3/4 of it and looks like they havent been touched in a while. Other one looked pristine and has no leaks at all.

Was always told to replace while its apart.

[Blunet600]

Update on the fork situation. Turns out is was a tiny chip on the stanchion which was causing the seals to leak. Ended up having to get a new stanchion....
Got the guy to replace the bushes anyway as i had a new set of honda ones.
Bike is all good now.

Right fork began leaking yesterday which sent me over the edge...fml.
Luckily though it turned out to just to be a bit of dirt. Fished that out and now it's golden.

Thanks for all the advice guys. Muchly appreciated.
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Honda - Power of Dreams - NSR 125R - Hornet 600

[P.]

I ended up buying new forks. Some of the mess inside one of mine was just daunting to look at.

Cost the same as bushes, seals and oil so hey