Changing fork seals with air?

[OzJavelin]

I've been reading the instructions for fork disassembly and not sure if I have all the tools required? eg. air wrench, or special holding tool But I've also seen people mention using compressed air to pop out the seals with the assembly intact. Is there anything in the folk which would be damaged doing this?

 

[sharpy]

Thats a hell a lot of compressed air i say. I have made a long t-handle with a 17mm nut on the end that goes down inside the forks and fits into the dampner rod and that lets you undo the 8mm allen bolt to pull the forks apart. While you have the forks apart its a good idea to run some wet 1600 grade emery paper up and down the seal surface while u spin the tubes in a lathe. Sort of hones the tube ready for the new seals. Post a pic of that t-handle tomorrow. Thats on a 1000 not sure what ures is.

 

[Nessism]

The hex on the outside of the common spark plug socket matches the damper rod too. Use a long extension and you are in business.

Regarding using air to pop the seals out, Salty Monk (Dan) reports to have used this technique with fine results.

 

[Steve]

Just make sure you take out the retainer clip and it takes a surprisingly little amount of air. Nothing inside the fork will be damaged by this, but if you are going this far into the fork, it's just a little bit farther and you can take it apart to visually inspect the parts that DO wear inside the tubes..

.

 

[salty_monk]

If you do pop them out with air you may need up to 170PSI depending how long they have been in there..... I did a couple of sets with a bicycle "track pump" (Stirrup pump).

You also need a length of waste pipe (buy a 2ft from Home Depot for about a buck) to use as a drift to put the seals back in. I think it's the 1 3/4" size that is the perfect fit from memory but double check.

When they "pop" remember there will be a rush of oily air coming out. Drain as much of the oil as you can first & hold a shop rag over the top to catch the "blast".

 

[Kaiser Sosei]

If you have never taken the forks apart to clean them, I would. When I changed out my fork seals I pulled the asembly apart and the "who knows how old it is" fork oil was more of a sludge than an oil. I took the opportunity to replace some of the wearing parts as well as the springs. Made a huge difference.

 

[twr1776]

Today 04:04 PM Kaiser Sosei If you have never taken the forks apart to clean them, I would. When I changed out my fork seals I pulled the asembly apart and the "who knows how old it is" fork oil was more of a sludge than an oil. I took the opportunity to replace some of the wearing parts as well as the springs. Made a huge difference.

+ 1, unless you know the full history of the bike I would also take them completely apart for inspection. Progressive springs and/or the Sonic straight rate springs get lots of compliments here, MUCH better than OEM and worth every penny IMHO.

 

[bwringer]

Once, when faced with a tight deadline and a damper rod tool that didn't work (41mm GK forks, and the hex inside is larger), I was able to pull the old seals out with drywall screws and replace them without disassembly.

I wouldn't recommend this, though. It would have been VERY easy to damage the forks (we used a lot of electrical tape to protect the forks, among other safety measures) and as noted, you don't get a chance to thoroughly clean things out.

But it beats missing the rally that weekend...