Z fork seal removal

[Scudrunner]

Just want to endorse the fill-the-fork with water technique for fork seal removal. The weeping seal in the fork of my Z wasn't coming out with any kind of leverage and I was paranoid about damaging something.

For anyone who doesn't know this technique, you drain the oil, remove the fork, take out the spring, extend the fork, fill with water, screw the cap back on (so it won't compress) and then use a hydraulic jack and an immovable object (the garage?) to pressurise the water until it "blows" the seal out. The only difficult bit is finding something strong enough to fit the fork and the jack between.

I'll be trying the "modified plastic waste pipe" technique described here on another thread to insert the new seal once I've cleaned all the crud out (do people use some kind of sealant - looks like the remains of soem locktight type compound in there?)

[Larry Zimmer]

Good stuff, there. The 'crud' explains why the seal didn't remove by using the upper fork tube as a pull-hammer. If the seal bore is good condition (no scratches, corrosion, etc.) no sealer compound is needed. I would suggest you might use some 320 grit sand paper to clean the seal bore. Just be certain to move around the bore; NOT up-and-down. 'Wash' things well afterwards to remove any and all grit. The 'waste pipe' tool works very well. Install the seal, and other bits, to just deep enough to be able to start the snap-rin. Then, install the snap-ring into the bore; and, using the 'tool', drive all parts 'home' When the snap-ring falls into its groove, everything will be nicely square; and, seated to a proper depth. Good luck with the project. If the finances are appropriate, you might consider a Racetech upgrade while things are apart. (approx $300 usd including parts and springs.)

[daves79x]

He's working on a '79 set of forks, Larry. At least I think so. No slide-hammer effect possible with them - no internal bushings to catch the seal. All I've ever done is cushion the outer lip of the lower and pry the seal out with a big screwdriver. Seems a lot of trouble he went through for a 30 second job.

Dave

[Scudrunner]

I did try using a big screwdriver, but was convinced that I'd either score the inside of the slider or damage the top. I half suspect that it was put in with some kind of sealant. Anyway, thanks for the tips on putting the new seal in - that's tomorrow's job. Wish me luck, weather looks good for a ride on Sunday.

[Larry Zimmer]

He's working on a '79 set of forks, Larry. At least I think so. No slide-hammer effect possible with them - no internal bushings to catch the seal. All I've ever done is cushion the outer lip of the lower and pry the seal out with a big screwdriver. Seems a lot of trouble he went through for a 30 second job.

Dave

Ah so, Dave -- YUP! That's how my old Suzy works -- just slide the lower off (after removing the piston retaining screw from the bottom) and pry the seal out. Even if someone permatex-ed it in. Put a little heat to it to soften it; and, out it comes.

[Scudrunner]

Yes, I guess heat might have been another technique I could have used. I finished the job over the weekend - 2nd fork was so bad that the circlip came out in several rusty pieces! Agian the water method blew the old seal out without damaging anything.

Cleaned up, new seals, dust covers and oil now in and she handled noticibly better on the 50mile run I did yesterday (wasn't much oil in forks before)!

I'm now thinking about doing the same thing on my GL1100 naked lady (front end seems under-damped now c.f. the CBX).

[Larry Zimmer]

Goood 'stuff'!! What a difference a few bits and a little wrenching can make, eh. It did sound like a case of serious neglect on the part of Previous Owner. Have a great Summer. Ride safely,