Replacing fork seals

[waterman]

I just use an air powered impact wrench on the allen screws. Never had any problem, didn't need to stuff a broom stick down the tubes. Hard part is locating a long reach allen socket to go on wrench.

It is also easier to loosen the threaded top piece with the forks still in the tripleclamp. Not all models use a threaded cap on top, but the forks act like a vise and make it easy to loosen.

Two tips for the seals, to prevent new seals from getting damaged while installing, use a thin plastic bag lubricated with oil to go between seal shock tube while sliding seal into place. Secondly, when setting seal in place, use the old seal as a battering ram. I just place old seal on top of new seal and then with rubber mallet, drive new seal into position.

[Headphase]

just one other thing you may need to consider.

The forks on the bike might not be the forks that were on the bike originally, so you should measure the seal sizes, so you get replacements that fit the forks.

I recently replaced the fork seals on my gs650, and ordered the seals for it, when they arrived they were miles too small, so I guess some po had replaced the forks in a past incarnation. Had to measure the slider, and the stanchion (or whatever the actual bottom leg bit is, and then went along to a local shop and just bought fork seals that size.

Don't worry about changing the fork seals though, it looks harder than it is. And once you've done them, you'll wonder what the fuss was all about.

[hikermikem]

Another thing which is not actually a tip, but 15W fork oil is the most popular weight. Pick up a jug when you get new seals. Fill up the forks to within 5.5” of the top with the springs removed and the forks fully compressed.

Ed,

Is this applicable to all forks? My 850GLZ fork oil height is OEM specified at 10.2". And that's where I set it...

However, the Progressive instructions state the 5.5" height you have said.

Should I have set the oil height at 5.5" for the PS set-up I'm using? Or should you always follow the OEM spec?

Mike

[tfb]

To get right oil level... cut the straw on a spray bottle to the right length, rest the cap on the top of the fork leg & pump any excess oil out. Works great & is very quick.

A stroke of genius!

[catbed]

See, this makes me feel even better about getting another set of forks. When I replace the forks that are on there with this set and pull the bastards apart and run into this ****, boy will I be glad for getting the spare! Same thing with the carbs, you just never know .

and then when you run into the problems on both sets of forks, you're still gonna have to replace them.

ask around, maybe someone will help you out if they're local.

[Clumzi]

Thanks Don, it's an old trick I found working on Mountain bikes. The fork legs are so skinny it's a real pig to find a level.

The 80 550 I did recently I didn't have to put anything down the legs to get the bolts out, maybe I was just lucky but there seemed to be a chamfer on the damper rod & it that would lock it out enough to tighten or loosen the bolts.


Clumzi - No! The bulk of the work in my opinion is removing the wheel, brake calipers, forks from the trees etc. If you have to dismantle that parts bike you'll be doing the time consuming bit twice & you'll still probably have junk forks....

Dan

I dug this thread back up because I'm back to where I was before. The replacement forks I got won't work (like some of you guys said ) and I don't have any way to weld a 19mm socket onto a piece of rebar. If I'm reading this correctly, are you saying Dan I might luck out and not need to hold the nut or whatever it is at the bottom of the fork to unscrew the bottom? Something still isn't clicking in my head about all this no matter how much I look at old threads, Mr Matchless' instructions and the shop manual. Am I making this harder than it really is? -nick

[chef1366]

Go to Harbor Freight and get an electric impact. Get a 1/2" to 3/8" socket adapter and a metric allen wrench set with 3/8" socket ends.
Before taking the spring out take the impact to the bottom allen wrench. It'll come right out. If not use a little heat from a torch. (not flashlight )
Have an oil pan ready for the old fork oil. Take off the fork cap and all the innards and lay them out on a table in the order they came out. This would be a good time to measure the fork springs to make sure they are in spec. Clean everything with brake cleaner. Let dry. Pry the old seal using screwdriver with a piece of leather or cardboard at the opposite side of the screwdriver end to protect the fork. Work its way around and around until it pops out.
Put everything back in and before adding the oil put in the spring and fork cap and with some blue loctite put the allen bolt back in with the impact.
Take the spring out, compress fork and add the oil and measure the oil level to the top of the fork. Your manual should give you a spec. I used a long bolt and measured my spec in inches and marked it on the long bolt and used it like a dipstick. Pour off excess or add if fluid doesn't show on "dipstick".

[Clumzi]

Go to Harbor Freight and get an electric impact. Get a 1/2" to 3/8" socket adapter and a metric allen wrench set with 3/8" socket ends.
Before taking the spring out take the impact to the bottom allen wrench. It'll come right out. If not use a little heat from a torch. (not flashlight )
Have an oil pan ready for the old fork oil. Take off the fork cap and all the innards and lay them out on a table in the order they came out. This would be a good time to measure the fork springs to make sure they are in spec. Clean everything with brake cleaner. Let dry. Pry the old seal using screwdriver with a piece of leather or cardboard at the opposite side of the screwdriver end to protect the fork. Work its way around and around until it pops out.
Put everything back in and before adding the oil put in the spring and fork cap and with some blue loctite put the allen bolt back in with the impact.
Take the spring out, compress fork and add the oil and measure the oil level to the top of the fork. Your manual should give you a spec. I used a long bolt and measured my spec in inches and marked it on the long bolt and used it like a dipstick. Pour off excess or add if fluid doesn't show on "dipstick".

This makes a bit more sense to me. Loctite is the only curiosity to me. Is this like teflon tape? Just something to make it seal better? I've been wanting a little palm impact driver anyway, I can buy one of those.

One more question for you sir, chef1366.... what is 1366 in reference to? You didn't bore an 1100 to 1366 did you? If you did, I want pictures, I don't think I've seen anything like that . -nick

[chef1366]

Loctite is a thread lock you put on the allen bolt to keep it from coming out. It has nothing to do with the seal.

Actually my bike is bored to 1166.
1366 is a secret.