Front Fork Seal- Leaking Problem.

[Noel Hynes 28]

Hi everyone...

 

I have a 2014 NC750 DCT with just under 5000 miles on the clock. Two years ago I had some leaking oil on one of the front forks- so decided to get them both done- this was done at 3,800 miles approximately by a mobile motorbike mechanic who someone recommended.

 

After a few hundred miles- the nearside one started leaking very badly again- so in August last year- I removed the fork and took it to the mechanic who did both the previous year. This was done in August last year- new seal replacement- and sadly it has started leaking again after doing about 300 miles.

 

My question is any ideas what is causing it ?? The mechanic did say the stanchions could be pitted and this could be damaging the seal- but he is not 100% sure.

 

He has said if I bring the bike over he will check it out. I am not sure what to do- either allow a 3rd attempt- or would it be better to try and get a new stanchion or the existing one re chromed- or does anyone have any ideas which could be causing the leak etc.

 

The oil is all around the stanchion in circular rings....the other one is perfect.

 

So far I have paid just under £200 for the work and not keen to spend more money again and the problem is still there.

 

Many thanks. Noel.

[Steve T 1,331]

I'm going to guess that the bike is left on the side stand for prolonged periods (weeks/months/years)!

This can lead to the left leg seal de-forming slightly, hence the oil getting out of that leg and not the RH leg.

If, after 2 changes of fork seal it is still leaking, I'd get him to fully dissasemble the left leg and check the bearings within the LH leg. If one (or there may be two bearings is these forks) of the bearings has been de-formed or damaged by the prolonged extra wieght being applied to it/them when on the side stand then they will need to be changed to get the fork stancion aligned properly.

 

Just a thought.

 

Steve T

 

[djsb 492]

Get your stanchions rechromed at Philpots in Luton. You won't regret it.

[jeremyr62 2,559]

That's a new one. If the chrome is pitted then you will be able to see it/feel it. Feel around the swept area of  the stanchion for any raised spots where the corrosion product stands proud of the chrome. You will need to fully extend the fork and maybe prise off the dust cover on top of the slider to check it all. Honda stanchions are hopeless at resisting rust but it's the swept area that matters. Rust above this just makes getting the forks out of the triple tree harder. I cannot imagine how the bushings or seals for that matter are going to be deformed from the bike being left on the side stand.

 

You need to check the stanchions really carefully as a first cut.

 

If the mechanic really said the stanchions "could be pitted" then you need to find another mechanic.

[Skidt 1,306]

A few years back I had similar issues on my Fazer 1000. It wasn’t getting a huge amount of use at the time and when I did eventually dig it out, after protracted periods of hibernation, in a cold damp garage, it blew one or more of the fork seals.

 

I initially had these replaced with pattern seals, rather than OEM. This, in the long run, proved to be a false economy.

There was no obvious pitting / rust spots on the stanchions that could be damaging the fork seals on compression. There were however, under close examination, some minor vertical scratch lines on the lower part of the chrome Stanchion, near to the seal (swept area) when the bike was at rest. This was, I believe, being caused by worn upper bushes below the seal. I decided in the end to replace the stanchions with brand new ones, along with new Yamaha fork seals and bushes. 

Clearly that wasn’t a cheap option but thus far, I’ve had no further issues. I personally now will only use OEM fork seals. 
 

I also make a point of either using the bike more, or at least moving it about the garage and compressing the forks every now and then, thereby keeping them moving and lubricated a little over the winter months. 
 

I hope you manage to get it sorted without too much further cost. 

[davebike 943]

Low milage bikes standing a lot  cause the seald to harden and stick to the tubes 

We see it a lot in the spring !  

If there no pitting no issues can be worth using expensive  Honda seals and a new set of bushs 

Pitted re chrome as said Philpots in Luton. and fit new seals and  bushes

[Xactly 5,419]

And while you’re at it fit fork gaiters.

[Graham 3,163]

My 2014 had a similar problem. After the first time they were replaced and gaiters were fitted.

When it was sold and was checked over the same left fork was leaking again.

They were replaced 3 times in 50,000 kms.

I wondered if it was from falling over 3 times on the right side while parked?

Edited May 4, 2022 by Graham