2 STROKE WORLD .net

The 2-Stroke Garage => Turning Wrenches => Topic started by: AAAltered on February 08, 2025, 12:56:58 PM

Title: Fork Seals Help
Post by: AAAltered on February 08, 2025, 12:56:58 PM
Doing the seals in my RD200.

I have pulled the stancions from the legs, fully exposing the old seal.
It was impossible to pull out other than pry, snip etc little bits at a time.

Now I am at the point where a lot of the old seal is out but a lot of it seems to have become one with the aluminum.  I've got it is a Xylene soak right now to see if that loosens or cleans things up.

Beyond that, any tips?

(https://i.ibb.co/9BmM4Z0/IMG-3083.jpg)

(https://i.ibb.co/mVHP9HBf/IMG-3084.jpg)
Title: Re: Fork Seals Help
Post by: m in sc on February 08, 2025, 02:22:48 PM
you probably need to collapse  it IN thrn pull out. man, that sucks.those forks are really giving you the business
Title: Re: Fork Seals Help
Post by: AAAltered on February 08, 2025, 02:26:51 PM
They have zero pliability...hard as rocks.  Let's see what the overnight in solvent does...I also have Acetone, right now it's in Xylene.  Hell maybe I'll use a propane torch,
Title: Re: Fork Seals Help
Post by: RDnuTZ on February 08, 2025, 02:56:03 PM
Did they have a metal band on outer perimeter of the seals? I've bought a few sets of NOS OEM Yamaha seals over the years that have the metal band on them, whereas aftermarket do not. Currently have those for 1976 YZ/IT400 and our RD250/350 models. Still in the original Yamaha bags with p/n labels on them.
Title: Re: Fork Seals Help
Post by: irk_miller on February 08, 2025, 03:05:13 PM
Take a sharp chisel punch and hit the seal's band 90 degrees to the fork wall, being careful not to gouge the aluminum. It will pull up the band enough to get a screwdriver with duct tape wrapped around the shaft to pry the band into a moon shape you can pull out with pliers.
Title: Re: Fork Seals Help
Post by: RD350NL on February 08, 2025, 03:23:28 PM
Take a dremel with the thin milling attachment and mill the seal through at one point. Then punch it out with a hammer and screwdriver and a lot of heat. Be careful not topri top much as you will destroy the fork upper ring.
Title: Re: Fork Seals Help
Post by: RD350NL on February 08, 2025, 03:24:30 PM
Quote from: RD350NL on February 08, 2025, 03:23:28 PMTake a dremel with the thin milling attachment and mill the seal through at one point. Then punch it out with a hammer and screwdriver and a lot of heat. Be careful not too pri too hard as you will destroy the fork upper ring.
Title: Re: Fork Seals Help
Post by: m in sc on February 08, 2025, 07:00:14 PM
heats going to be your friend here.
Title: Re: Fork Seals Help
Post by: AAAltered on February 09, 2025, 11:58:28 AM
Great advice e everyone, thanks.  (Like the duct tape trick).
Soaking overnight got more rubber out.  I was able to clean out a bit more with a rotary wire brush.

It does seem to have a steel band in there that may be part of the old seal or may be part of the fork inner, I can't tell.

See what I'm pointing at with the dental pick.  The pick isn't strong enough to pull it out, if it's even supposed to come out.  I could grab it with a needle nose but haven't yet.

Since I don't have the new seals in hand yet I don't have a great reference for what their shape is.

Thanks

(https://i.ibb.co/vvdNdvtj/IMG-3085.jpg) (https://ibb.co/wrQnQrvz)

(https://i.ibb.co/mCKSWCK2/IMG-3086.jpg) (https://ibb.co/4ZLJrZLX)
Title: Re: Fork Seals Help
Post by: AAAltered on February 09, 2025, 05:32:28 PM
Ordered all the stuff from Yambits...
Title: Re: Fork Seals Help
Post by: 1976RD400C on February 10, 2025, 09:01:00 AM
You still have some work to do. I would sock the heat to it and see if that helps.
Title: Re: Fork Seals Help
Post by: RDnuTZ on February 10, 2025, 09:40:23 AM
any chance heat will distort the circular shape of the fork tube where the seals live?
Title: Re: Fork Seals Help
Post by: Simoniz on February 10, 2025, 10:37:06 AM
I had to remove oem fork seals put in at the factory in Japan in 1974 from a Kwak 400 recently, and they were just as tough as these to get out. I used the Dremel cutting wheel in the end, a seal puller didn't touch them at all. I feel your pain.

Title: Re: Fork Seals Help
Post by: m in sc on February 10, 2025, 12:26:03 PM
nah, heat won't warp them . we'll too much and it goes liquid but, that's extreme and most hand held torches won't do that
Title: Re: Fork Seals Help
Post by: AAAltered on February 11, 2025, 05:40:47 PM
Well first off, you have to hand it to YamBits.  Parts ordered Sunday night are already in Newark NJ USA and will be at my house tomorrow.

I took the second fork apart today and run it in the heated ultrasonic for a while.  The seal came out with relative ease, a small flat blade tapped in and a little pry. 

I took the opportunity to run everything through the hot sonic, I'll be ready for the parts to land...

(https://i.ibb.co/0VrTHfqt/23849703-5-F5-B-4108-BD90-1-D6636-E5-CA94.jpg)

(https://i.ibb.co/LjDwchQ/56-B4-DD63-6484-4-DA1-96-C8-25-C816-F17-EF4.jpg)

(https://i.ibb.co/pBFhFMsP/76057799-4-BF0-482-C-8967-B01-F37116-AEE.jpg)
Title: Re: Fork Seals Help
Post by: m in sc on February 11, 2025, 06:14:54 PM
congrats!  :olaf:  i know you know this, but def smooth out the nicks where the seal sat. you may want to use a tad of sealant in there upon reassembly, the anaerobic stuff from Permatex is non hardening.
Title: Re: Fork Seals Help
Post by: AAAltered on February 11, 2025, 08:57:38 PM
Yea Mark, it's obvious that a hamhand other than me has been in there in the last 49 years.... I'll clean them up before the new seals go in.

Title: Re: Fork Seals Help
Post by: 2T5 on February 12, 2025, 12:19:45 AM
Quote from: AAAltered on February 09, 2025, 11:58:28 AMIt does seem to have a steel band in there that may be part of the old seal or may be part of the fork inner, I can't tell.

What was the outcome here? Was it part of the old seal, and how did you end up getting it out?
Title: Re: Fork Seals Help
Post by: AAAltered on February 12, 2025, 09:48:01 AM
That WAS part of the old seal.  Once I knew it (by getting the other seal out intact) I used a small flat blade and was able to tap it in behind the band and pop it out.
Title: Re: Fork Seals Help
Post by: RDnuTZ on February 12, 2025, 12:46:28 PM
example of OEM banded fork seals from eBay. (not mine).

https://www.ebay.com/itm/314280825684

Title: Re: Fork Seals Help
Post by: AAAltered on February 12, 2025, 01:19:41 PM
Yup, has to be them.

This is the metal band I pulled out last night.
(https://i.ibb.co/fVp5K38g/IMG-3091.jpg)
Title: Re: Fork Seals Help
Post by: AAAltered on February 15, 2025, 11:11:52 AM
Ok, so which faces DOWN on the new seals?  Left one or right one? 
I suspect the right one, as that puts the wiper part of the seal at the top.

(https://i.ibb.co/5gCwnKWW/image.jpg)
Title: Re: Fork Seals Help
Post by: 1976RD400C on February 15, 2025, 01:58:53 PM
Yes, the side with the spring goes down into the tube when installing.
Title: Re: Fork Seals Help
Post by: AAAltered on February 15, 2025, 02:44:02 PM
Who knew, a 30mm socket is a perfect seal driver...

(https://i.ibb.co/Z6HVJZV7/image.jpg)
Title: Re: Fork Seals Help
Post by: AAAltered on February 15, 2025, 03:05:05 PM
Put the legs in the oven for 10 minutes at 175, seals went in easy with the driver.  Rings and retaining clips back in and good to go...

Thanks for all the tips gang.

(https://i.ibb.co/qM0wFQkf/image.jpg)
Title: Re: Fork Seals Help
Post by: axldk6 on February 16, 2025, 07:03:14 AM
jumped on this thread to give ya a thumbs up  :thumbs: . hope mine goes as good , lol
Title: Re: Fork Seals Help
Post by: axldk6 on February 16, 2025, 07:04:08 AM
jumped on this thread to give ya a thumbs up  :thumbs: . hope mine goes as good , lol
Title: Re: Fork Seals Help
Post by: Simoniz on February 16, 2025, 09:08:16 PM
Good to hear you got it sorted out. These "simple" jobs can be the worst ones.

I use a 2 foot offcut of PEX plumbing pipe in the same diameter as the seal to drive in new fork seals easily. Fits snugly and provides even pressure to push it home when hammered in lightly. Usually found in the offcuts box at the local Ace Hardware for $1. As you found, sockets work fine too.
Title: Re: Fork Seals Help
Post by: AAAltered on March 19, 2025, 11:22:32 AM
Just to close out this thread from the other week.  Seals out, seals in.  Crappy gators are gone and replaced with correct dust seals.  The pitting on the fork inners isn't that bad, none is near the seal travel. I took Marks advice and turned the most unsightly areas inward.  I did buy a silver marker, not sure if I'm going to use it as it didn't seem to hold up too well in a test spot even though it's solvent based.

Anyway the bike was back together and tested.  Now it's getting some other maintenance items like tank dampers, rear brake switch replacement and overall deep cleaning.

(https://i.ibb.co/HpBb0ks2/IMG-3112.jpg)
Title: Re: Fork Seals Help
Post by: RDnuTZ on March 19, 2025, 11:45:06 AM
 :metal:
Title: Re: Fork Seals Help
Post by: SoCal250 on March 19, 2025, 03:03:30 PM
Looks good! :clap: And much better without gaiters :thumbs:
Title: Re: Fork Seals Help
Post by: AAAltered on March 19, 2025, 04:31:16 PM
I agree Russ...
Title: Re: Fork Seals Help
Post by: m in sc on March 19, 2025, 06:19:43 PM
yup. looks great