front fork...trying to fix myself

[boathead]

in the general discussion area, i started a thread about the cost of a fix...with the prompting of a few, i'll give it a try myself.

i ordered some pro moly seals, and await their arrival.

in the meantime, i'm wondering if i don't need something else...specifically, my fork ABOVE the dust guard was getting wet with oil after a ride. now, i truly believe i need a new oil seal, as there is dripping down low....but what would explain the top side wet? do i need to replace something else?

first of many questions i'm sure. thanks.

[DanTheMan]

Check your camshaft covers and tach drive for leaks. A fine mist can come from those areas to coat the forks, or even a small head gasket leak will do the same.

[boathead]

dan, it's not motor oil...and it's only on my problem port fork, and the line where the wet starts/stops is very distinct, such as where the fork might have compressed during a ride. so i'm thinking it is fork oil.

what is it in the fork that keeps the oil down inside the fork?? the oil seal keeps it up in the fork, right? what keeps it from coming out the top side??

(i fully confess that i might not be understanding this fork stuff at all at this point, so newbie questions)

[TheCafeKid]

The wipers on the seals, which clean the upper stancheon as it returns from a compression stroke, wear out and more or less receed as the seal weakens...When that happens, oil can penetrate around the upper fork. Also, any pitting, rust, or other damage markings in the fork chrome will leave a passageway for the oil to pass. Pits and rust that have gone untreated with sandpaper/steelwool to smooth them will nick and tear at the seal, exacerbating the problem.

[DanTheMan]

There is also a seal at the top of the tube where the dust cover is to keep the fork oil from squeezing out of the top as the oil is compressed. It's the top seal also that will let the air out when it leaks. If you've ever looked at an oil charged shock absorber when it fails badly, oil squeezes out around the shaft seal in the same manner.

[ryonker]

The wipers on the seals, which clean the upper stancheon as it returns from a compression stroke, wear out and more or less receed as the seal weakens...When that happens, oil can penetrate around the upper fork. Also, any pitting, rust, or other damage markings in the fork chrome will leave a passageway for the oil to pass. Pits and rust that have gone untreated with sandpaper/steelwool to smooth them will nick and tear at the seal, exacerbating the problem.

Yeah, it's just fork oil. Both of the fork legs on my 78 were leaking like a sieve. The oil just stays up on the fork and probably blows up a little higher as you ride.

After I removed the forks I attempted to drain the oil...and found almost none. It had almost all leaked out.

Rick

[boathead]

so, based on this limited description of mine, should i order something else? or hope that the pro moly oil seal seals it a bit better?

[TheCafeKid]

What?? The seals are shot right? Thats why you ordered NEW SEALS??? I dont understand what you're asking

[boathead]

ugggh. did i jump the gun?

i have fork oil residue above the dust guard.

and i have fork oil leaking down low..unsure where it's coming from. might be the drain hole. i tightened that a bit, unsure if that will stem it.

i guess what i'm asking is this: will a new seal stop the down low leak as well as the residue above the dust guard?

[TheCafeKid]

No, if you have oil residue ABOVE the dust guard, your seals are SHOT. The bottom bit is probably just a loose drain screw, but you'll know soon enough when you pullem apart...

[boathead]

ok. i think i understand. thanks. my next problem is finding 19mm hex nuts...the hardware store had 18mm and 20mm. no 19mm.

[TheCafeKid]

Why do you need a hex nut?? You need a BOLT, with a 19mm head, and two nuts that are 19mm. To make the tool you will need to get the damper rod out. The bolt in the bottom is an 8mm hex head...

[TheCafeKid]

And actually, it REALLY doesnt matter what size the head is, so long as the NUTS are 19mm... so if you find a M14 or something and NUTS that will fit that are a 19mm socket fit, then you're good to go..

[ryonker]

And actually, it REALLY doesnt matter what size the head is, so long as the NUTS are 19mm... so if you find a M14 or something and NUTS that will fit that are a 19mm socket fit, then you're good to go..

Or, you could just use 24 inches of 1/2" threaded rod and the nuts that fit it. Those nuts are almost exactly 19mm OD (just checked) and other guys use this set up. Use two nuts at one end to lock up each other, and two on the other end to hold onto with a socket.

Rick

[boathead]

i understand. thanks. off to home depot tomorrow.