Leaking Fork Seals: What parts do I need to replace?

[Tim Tom]

Hey Everyone,

So I've noticed that my fork seals are seeping a little bit. I can see a line of dirt that shows how far the fork lowers have traveled, and there is a film of oil on the fork uppers.

Having never rebuilt forks before I'm not entirely sure what parts need replacing.

The bike is an 82 850G and as far as I know the suspension is stock. I haven't yet started to tear anything apart as its my only bike and I would rather not have in no-op mode for extended periods of time. Also I'm doing an advanced rider course on June 26th and NEED the bike to be operating then (the course is with your own motorcycle).

What parts are suspect to replacing and should I also look into upgrading the springs? Keep in mind I do not have much in the way of a budget as I'm a semi-starving college student so 300 dollar springs are quite out of my range. Ideally I'd like to keep it as cheap as possible but still be an improvement over whats there now.

Any advice?

Thanks,
Tim

 

[cowboyup3371]

Have you checked out Basscliff's website yet? he has a great writeup there on doing this exact thing.

 

[Tim Tom]

Yeah I looked it up just a few minutes before posting.

He just mentions be sure to have all of the parts on hand and then he lists some of them but I'm not sure whether that was an all inclusive list or just a few of the things needed.

I figured I'd rather be safe than sorry and have everything so I can do it in an afternoon without having to wait on any parts I forgot / didn't know to order.

 

[mike_of_bbg]

If you look around you can find Progressive springs for your bike for about $70 I'm sure. The springs can be done later without removing the forks though. Fork oil and seals. Might add some pre-load with some PVC pipe. Bigger PVC pipe to pound the seals in (unless you're using "leak proof" seals - don't pound those!). Start PB Blaster treatment on your clamp bolts (especially your lowers) a week ahead of time.

There's a tool you need to make to get the fork lower bolts out as you've surely seen if you've read BassCliff's guide. Have 600 grit and WD-40 on hand to gently wet sand any pits in the travel area.

A spray bottle head from an old Windex bottle makes a nice fork oil level gauge and level setter.

 

[Guest]

One tip:

Loosen the fork caps BEFORE you remove the forks from the bike. It's a whole bunch easier to break that cap free while it's still mounted on the bike...

 

[DPage]

Tim Tom, I did all this to my bike last year. Look for an Excel spreadsheet in your e-mail (not PM) with all replacement OEM part #'s and some tips. Enjoy!

 

[BassCliff]

Hi,

Have a look at these PDF files:

Install Progressive Fork Springs

​

Fork Seal Replacement

Fork Seal Replacement
(by Mr. Matchless)

Look in the parts fiche. If your forks are similar to mine you've got an O-ring at the top to seal the caps. There's a brass washer on the bottom damper bolt. There's a nylon bushing in the middle (that rarely needs replacing), the dust covers, and the seals themselves. The last time I did my fork seals I replaced only the seals and dust covers. Next time I'll probably replace the O-rings, damper bolt washers, seals, and just check the bushings for excessive wear.


Thank you for your indulgence,

BassCliff

 

[1_v8_merc]

1.)Fork seals

2.)Allen key or whatever that tool is for the bottom
(take a look)

3.)Tool to release the C clip, or whatever it's called
(pop the dust covers off the forks, you'll see it. It basically holds the Fork Seal down, with the help of a large washer. There's 2 small holes that you squeeze together and that allows the C clip to come out. There is a special tool set for THIS....I guess you can get it at Lowes, Home Depot, Autozone, etc. If you don't have the tool, it's going to be tricky to do it, but it can be done)


4.)Fork oil
(You can buy premade fork oil that you pour in, but you must be aware of the capacity your fork allows. You might have to make some weird squirt bottle gizmo to remove oil, in order to get the level right....Personally, I remove the springs and everything, clean Every Spec of fluid out of the forks, then reassemble, then make my Own fork oil with 15w or 20w motor oil and ATF, pour it in a measuring cup to the exact capacity that the GS manual says, then pour it in.)


5.)PVC pipe(to press in new seals)
(I think it's 2" PVC, Lowes and Home Depot have like a 4ft piece for under $3.)


It's very easy to do the seals.

 

[mike_of_bbg]

Sometimes the Old Seals get stuck, and you gotta yank the tube real good And fast to pop em off.(make sure that bottom bolt it out FIRST before you go yanking those seals off!)

If your forks have air valves, you can use an inflator pump to blow the seals out (AFTER you drain the fork oil and put the plugs back in ). 150psi or so seems to do the trick.

 

[hampshirehog]

If your fork tubes are pitted you might need to replace them (the pits can rip seals to shreds in no time).

 

[Tim Tom]

Thank you for all of the responses guys! Especially DPage, your spread sheet is fantastic, and just what I was looking for. It looks like I'll be doing this sooner than later .

Thanks again for all the tips and advice, much appreciated guys.

 

[metalman]

For what it's worth please spend an extra $11.00 and replace the fork rebound springs on bike this old. Best to rebuild only once and have no surprises. Also the O rings are not that expensive and would be best done at same time IMHO. Just put progressive springs in forks 78 GS1000 couple of days ago and ended up with same problems started with as rebound springs worn out also not really big surprise considering age. Am now waiting on the rest of parts to do it right.
http://www.powersportspro.com/pages...982)/FRONT_FORK_(MODEL_D)/02880001/5602880044

 

[cal_look_zero]

The perfect cheap (if you already have the tools) damper holder. That's a standard 5/8" sparky socket inverted and 18" of extensions. Easier than trying to fab up something.

 

[Jason the terminator]

If your forks have air valves, you can use an inflator pump to blow the seals out (AFTER you drain the fork oil and put the plugs back in ). 150psi or so seems to do the trick.

Tried this today and didn't work.

 

[metalman]

Tried this today and didn't work.

Guess was just lucky as mine came right out using automotive drum brake adjusting tool. One thing I found beneficial was to take a piece of flat metal that fit my vise and drilled holes to match the forks where rotors bolt on forks and fit in vise, made job much easier for me. Had to remember to use a level when pumping out excessive fork oil. Will be replacing the damper springs next weekend and will take pictures of this. Hope it might be of benefit to others.

 

[mike_of_bbg]

Tried this today and didn't work.

Spray them with some PB Blaster around the outside edges and give the air compressor some time. I've heard of it taking 10 minutes or even longer for the air to blow out the seals, though mine were almost instant once they reached ~160psi. If the seals can't hold back the air or you have leaks elsewhere it might not work.

Time and pressure...

 

[1_v8_merc]

The perfect cheap (if you already have the tools) damper holder. That's a standard 5/8" sparky socket inverted and 18" of extensions. Easier than trying to fab up something.

LOL!
Don't you own a REAL extension?

Just kidding, but I also have a drawer filled with all sizes of extensions....I think If I hooked 'em all together, I would get "0" lbs of force.....lol

 

[Gregory]

Hi,

Have a look at these PDF files:

Install Progressive Fork Springs​

Fork Seal Replacement

Fork Seal Replacement
(by Mr. Matchless)

Look in the parts fiche. If your forks are similar to mine you've got an O-ring at the top to seal the caps. There's a brass washer on the bottom damper bolt. There's a nylon bushing in the middle (that rarely needs replacing), the dust covers, and the seals themselves. The last time I did my fork seals I replaced only the seals and dust covers. Next time I'll probably replace the O-rings, damper bolt washers, seals, and just check the bushings for excessive wear.


Thank you for your indulgence,

BassCliff

Doing some research. Good thread, but the link is dead for Install Progressive Fork Springs