Safe Fork Seal Replacement

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ccubed
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Safe Fork Seal Replacement

Post by ccubed » Thu May 14, 2009 12:26 am

This is a safe and easy way of finishing off a fork seal change. Please read it in conjunction with Diesels fork rebuild in the workshop on the main site and masterofinsanity’s picture post on viewtopic.php?f=55&t=6035&p=47091&hilit ... vel#p47091

As the man said this aint no 5 minute job but here is a home made tool that makes the task a whole lot easier. The problem is that when you get to the bit where Diesel says “put the allen bolt back in the bottom to hold the internals together and stop oil leaking out of the bottom.” You need to compress the fork spring which may require 50% of the force you would need to bottom the forks out braking from 130mph with the back wheel hovering in the air. That is a very heavy friend. :smt006

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So in Blue Peter style this is what you will need:

6mm Hex key
2 tie down straps ratchet variety.
2 M8 eye bolts – made by dismantling a pair of M8 anchor bolts
1 piece of hardwood approx 15mm thick x 200mm long x 80mm wide.

Cut a 28mm hole in the centre
File 25m wide guides for the straps either side of the hole. About 100mm gap between them.

The task – The hex bolt with its copper gasket washer has to be screwed into the bottom of the fork internals.

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Put it together.

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Screw down the fork cap. Carefull not to pinch the O ring.

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Now we will use the parts we collected to compress the fork almost the full distance of the exposed chrome. Insert one eye bolt into each side of the bottom of the fork. Put the hex bolt and gasket into the bottom of the fork first as the eye bolt stops you doing this later on one of the forks.

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Pass the tie down straps through the eyes.

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And round the wooden block placed over the fork cap.

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Here is a second view of the straps and wooden block.

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The exiting bit is how easy it is to compress the fork with the ratchet tie downs.

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With the fork fully compressed, screw in the hex bolt using some non permanent loc tite.

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And dismantle the contraption.

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Then remove the end cap and fill with 424cc oil.

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Thats it, celebrate. :excited

Take care the cup washer on the bottom of the spring inside does not drop off as it can stop the compression and you will need to start again. To prevent this try to keep the whole thing up-right untill the compression is done and you have got the screw in.

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Re: Safe Fork Seal Replacement

Post by masterofinsanity » Thu May 14, 2009 9:08 am

Thankyou and welcome, excellent idea!! :excited
Don't forget people there is more to the zxr400 than this forum... check out www.zxrworld.co.uk also.

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Re: Safe Fork Seal Replacement

Post by cargo » Thu May 14, 2009 9:32 am

That eye bolt looks very very bent to me.....................................after you put the tension on.........................I'd hate to think what would happen if it broke..................... never mind the problem of removing the broken bit from the fork

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Re: Safe Fork Seal Replacement

Post by Scott221 » Thu May 14, 2009 10:16 am

I was thinking that lol.
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Re: Safe Fork Seal Replacement

Post by RedexRobB » Thu May 14, 2009 2:36 pm

Quality!

Thanks very much for the write up! And welcome to the forum :)

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Re: Safe Fork Seal Replacement

Post by zxrsean » Thu May 14, 2009 4:57 pm

on 1 pic is stright and the other its bent before its been tightened :smt004

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Re: Safe Fork Seal Replacement

Post by ccubed » Thu May 14, 2009 11:19 pm

Some observant bikers out there! I did this a couple of times with the old seals and no oil to check the method before actually replacing the seals. The less supported eye bolt did bend the first time but it is in fact easier to get out now because of its shape. Those anchor bolts are quite soft, there is no chance of snapping an Mild Steel M8 bolt with one bend. Just always use it the same way up! If it did break it would be the same as releasing the straps one at a time which is probably the scariest bit :shock: but its fine, the unwinding of the straps damps it enough. I can assure you, I did not have to retrieve the fork off the neighbours roof!

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Re: Safe Fork Seal Replacement

Post by masterofinsanity » Sat Aug 28, 2010 10:40 pm

this thread gave me ideas when i did my TLR fork seals last weekend, i made a tool at work and with a 25mm ratchet changed both forks easily. cheers for the hints.

ps you could use a similar tool to do the zxr forks.
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Don't forget people there is more to the zxr400 than this forum... check out www.zxrworld.co.uk also.

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