B25 fork oil leak

[Jim_Hines]

Morning all,

I've got a BSA B25 and I've got an oil leak from what I imagine is a fork seal.

After riding last weekend, came down and noticed a pool of oil under the front forks on the garage floor, about 18" in diameter.

It appears to only be leaking from one side.

I've only had the bike about 2 months. When I first got it home, I noticed the fork drain screws were only half in, so I screwed them up fully. It wasn't leaking anything at this stage...

I've looked at some YouTube videos of replacing the seals, and it seems it's a more complex job than I can do with my limited knowledge and tool kit.

Before I find someone who can do the job for me, is there anything else I can check or do? Could it be anything else?

Would just like to get the last month of "summer" riding in before I park it up for the winter.

Thanks,
Jim

[neil1964]

I suggest you buy a bottle of 20w fork oil.
Drain both legs of oil (gently pump to remove the dregs)
Remove top nuts and replace the drain screws with new washers and refill each leg with correct amount of oil (can't remember but 190ml if I recall - but do check).
Then ride it. 
If it is leaking oil from the screw it will stop and if it is the seal you will know as this oil will run down the leg when you are riding. 
You can also lift the gaiter and see if the oil is puddling in the seal holder.
You don't need any special tools if you have a fabric strap wrench (like you use for spin on oil filters.
All you do is whip wheel off with frame supported ideally on blocks.
Then hold the seal holder with strap wrench and unscrew the bottom leg from the holder.  There is a circlip on earlier bikes that needs to be prised out from upper inner aspect of the fork leg (later shared Triumph forks don't have this but there is an o-ring.
Put the leg to one side. Slide the seal holder off after removing the bushes and knock the seal out from above. Inspect the stanchion for scores/rust/pitting.
Put a new seal in the holder correct way round and tap in with a socket.
Slide oil seal holder onto stanchion taking care not to damage it on the lip at bottom of stanchion (bit of tape helps smooth it.
Then reverse process.
Full strip to remove stanchions needs the leg puller.  I also have the seal holder pegged spanner that goes from above but the strap wrench works.
Hope that helps.

[Jim_Hines]

Hi Neil,
Thanks for the advice.

I've ordered the some washers over the weekend so when they arrive I will try those first and go from there.

I don't have any oil leaking around the outside of the forks, only at the bottom from inside so that seems the best place to start.

Also, on this bike it doesn't have gaiters so I can't see much.

Thanks again.

Jim

[Jim_Hines]

Neil1964

Thanks for your advice.

I replaced the washers on the drain screws and that seems to have fixed it.

Only question I have though is while the wheel was off I found both the stubby bolts that go up the inside of the forks to be loose. These are Allen key head bolts. I can't find anything in the manual about them.

Neither of them had washers on. Should they have? If so what sort?

Both appear to be sealing as nothing is leaking, but it doesn't seem right.

I hope this makes sense.

I haven't worked out how to reduce a picture size yet so am struggling to upload a picture for reference.

Thanks,

Jim

[neil1964]

These bolts hold the damper cones.
They should have a sealing washer (copper?) as they are supposed to be tight and sealed
You need a really long socket extension to hold them to first undo and remove, add the washers and tighten
Your forks may clash, clunk and lose oil from them

[Jim_Hines]

Hi Neil,

Thanks for your advice.

I've just ordered some copper washers and am going to have a play with it at the weekend.

Thanks,
Jim

By the way, your not local to Chelmsford are you???

[Stevegayler]

Hi Jim. You could use a length of dowel to hold the cone. It's just a matter of putting pressure on it.

[Jim_Hines]

Hi Steve,
Thanks for the advice. 

I've just finished tinkering and added the copper washers.

I didn't actually need to hold anything down the inside of the forks to tighten the bolts in question, they simply un done, I added the washers and then replaced them... so I'm not sure exactly what the crack is with my forks...

Never touched a set of forks before so lots to learn.

Thanks for all the help so far.

Jim