Author Topic: Removing fork Oil Seals  (Read 7106 times)

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Offline Bondi Rabbit

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Removing fork Oil Seals
« on: October 08, 2013, 08:58:14 am »
 I have the YZ125x model, they are the forks with the giant heads on them for the air adjustment. Anyway I get the forks apart after a full day with the ratchet gun, and the manual tells me the fork seal should just ease out with a thick screwdriver. Well mine after being there for 37 years we like Bakelite and some bits broke off. But it feels like its welded in ( I know its not ) It also said give the fork some heat, well I tried that as well, but was worried how much to give it as the shock started getting hot. But still no removed seal. Is there a special tool ?  Could they be machine pressed in ? This is the last part of the restoration and its been the biggest headache. Any advice would be welcome 

Offline frostype400

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Re: Removing fork Oil Seals
« Reply #1 on: October 08, 2013, 09:22:37 am »
You usually can use your fork tube as a slide hammer hold the lower leg and slide the tube right down and then rip it up fast do that a few times and it should come out I know what you are describing I have had some tough ones to get out.

You do have the seal retaining clip out I'm sure you would if you have been breaking bit of the fork seal.

Then I usually cut the old seal in half to use as a driver for the new seal bit of paper round the fork tube to protect the chrome when you tap the new one in with a hammer and a half of the old seal.
1971 tm400 and PE's

Offline Bondi Rabbit

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Re: Removing fork Oil Seals
« Reply #2 on: October 08, 2013, 09:32:38 am »
I do have the retaining clip out. On  one  fork that  may  work but on the other seal  so damaged there is no retention or resistance in the seal so the fork is sliding in out with ease. Thanks for tip on the old seal to use for replacement.

Offline frostype400

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Re: Removing fork Oil Seals
« Reply #3 on: October 08, 2013, 09:48:44 am »
You should feel it bottom out on the seal though even if it is damaged if the tube pulls right out the seal and leg then you will have a good go at it to pry it out I haven't had that happen before though the seal would have to be pretty damaged.
1971 tm400 and PE's

Offline frostype400

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Re: Removing fork Oil Seals
« Reply #4 on: October 08, 2013, 09:55:04 am »
The seals have a steel ring that runs around them so you will battle to pry them out on an angle you need to try and get under them but if it is fully seated that is going to be hard I would just keep working it I know it seems like a bastard just remember your outer seal of the forks is just as important if you damage that your forks might leak.
1971 tm400 and PE's

Offline Bondi Rabbit

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Re: Removing fork Oil Seals
« Reply #5 on: October 08, 2013, 10:00:29 am »
Cheers will keep trying

Offline frostype400

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Re: Removing fork Oil Seals
« Reply #6 on: October 08, 2013, 10:09:49 am »
Good luck if you get your other one out you can cut it in half to use as you new seal driver and also you will see what you are dealing with on the other leg that is being difficult.
1971 tm400 and PE's

mainline

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Re: Removing fork Oil Seals
« Reply #7 on: October 08, 2013, 10:23:42 am »
I use a small tyre lever, the rounded end means less chance of gouging the inside of the fork leg, and using the lever end with the upturn means you can get under the seal better.
« Last Edit: October 08, 2013, 06:05:39 pm by mainline »

Offline YZ250H

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Re: Removing fork Oil Seals
« Reply #8 on: October 08, 2013, 11:02:46 am »
Give it a really good warm up with a heat gun then use Mainline's tyre lever method and it should come out  ;)
Looking for YZ250C parts NOS if possible

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Offline firko

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Re: Removing fork Oil Seals
« Reply #9 on: October 08, 2013, 11:25:20 am »
This reminds me of the YZ-A forks I did a few weeks ago, it took heat and my especially rounded screw driver to eventually get them out. When I got 'em  out I could see that some rocket scientist had glued them in two decades ago, probably Loctite. Prick of a job but all well after 4 hours of huffing and puffing. Heat is the key.
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Offline Bondi Rabbit

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Re: Removing fork Oil Seals
« Reply #10 on: October 08, 2013, 05:45:13 pm »
Thanks all . heading home to try again

Offline Bondi Rabbit

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Re: Removing fork Oil Seals
« Reply #11 on: October 09, 2013, 09:04:55 am »
Eureka ! one is off !

Offline Mick D

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Re: Removing fork Oil Seals
« Reply #12 on: October 09, 2013, 01:48:17 pm »
I hope this is food for thought, or at least helps someone.
 I love investing in tools, ones that make life easy and protect myself as well as the work piece from injury :)

I have a "made in Taiwan" TOLEDO brand one of these, it was three hundred bucks.
Earlier this year I noticed this exact copy for a fraction of the price, probably a copy made in PRC ::) but certainly value.
The thing I like about Toledo, is that its components are available as individual replacement parts.
So from now on I am thinking, buy the Chinese copy. Then if anything fails, just replace that component from
the Toledo parts list :)

http://www.ebay.com.au/itm/HELI-GUY-BEARING-PULLER-INNER-OUTER-SLIDING-HAMMER-1-5KG-FORGED/251342929585?_trksid=p2045573.m2042&_trkparms=aid%3D111000%26algo%3DREC.CURRENT%26ao%3D1%26asc%3D27%26meid%3D1850990534147020716%26pid%3D100033%26prg%3D1011%26rk%3D3%26rkt%3D4%26sd%3D141083558900%26

This old Snap-on seal puller that I have had for more than half my life, has also served me well
.

Rather than risk the fork leg slip in a vice or such? If I use this sliding hammer method, I grab a correct size bolt, same diameter of the axle size. Put the bolt through the leg axle hole and just throw a chain around the telegraph pole on the grassy knoll to anchor it.

There are all sorts of seal priers, levers etc

but you need to be extra careful not to slip and damage the seal-housing of course.

If you have a stuborn one that has been glued in, heat always helps of course.
 If you don't have the tools, do this
  Put a little acetone in a glass jar and soak the seal for a
"Couple a days". The old stubborn pain in the butt seal will simply turn to jelly ;)
   and so will most glues.

Good Luck.


« Last Edit: October 09, 2013, 06:38:33 pm by Mick D »
"light weight, and it works great"  :)

Offline frostype400

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Re: Removing fork Oil Seals
« Reply #13 on: October 09, 2013, 02:46:01 pm »
You can do a lot without great tools but if you plan on doing a lot of bikes having the right tools makes some difficult jobs very easy.

I have found most my forks came apart easily if I get stuck though I will buy what ever tool will do it.

The other week I got stuck on a head stem bearing it just wouldn't budge so I bought the park tool steering bearing puller done in 30 secs and already used about three times at the same I bought the head stem bearing driver.

Got a wheel truing stand, head stem race removers etc etc most can be done with out the tools but you just know that if you have them it is a piece of cake but they cost a bit so are if you aren't doing any volume sometimes they aren't worth buying for a one off job.

That is why I give my mountain bike to the bike shop to do they have all the right tools I only have the one mountain bike so it isn't worth me investing in thousands worth of tools for it if I had as many bikes as I do motorbikes I would.







1971 tm400 and PE's

Offline 80-85 husky

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Re: Removing fork Oil Seals
« Reply #14 on: October 09, 2013, 07:18:52 pm »
tell me more about that headstem bearing remover.. ive got a stubborn one (33 y/o) that wont listen to a block of redgum and a big hammer.
 I tried super tightening the collar, hoping to crack the "seal" but no luck.

heat is next after I rip the fuel tank off to prevent a small intense fire....