Hi

Just in the process of restoring 1974 TY250A and decided to replace the fork seals, having taken off the circlip and washer at top the slider there is a solid flange that covers the seal making it impossible to access for replacement - have tried all methods to remove it but it won't budge and seems to be weldTY250 Fork Seal.pdfTY250 Fork Seal.pdfed in [please see photo] - any guidance will be appreciated, thanks David

I have no particular experience of ty250a but I have come across simliar on other forks. The steel does get stuck absolutely rock solid to the aluminium/

Some people grind as much away with a dremmel as they can the peel the rest off.

I prefer to put MIG weld on as the heat breaks the bond and when it cools the steel "flange" shrinks away from the aluminium.

TIG can also be used and saves having to shield the aluminium against spatter.

your photo shows what looks like the steel innards of a seal with a piece cut out. You say you have tried all methods but did not mention which methods. To loosen the steel "flange", gentle heating of the aluminium slider around the "flange" would be a good idea. After that, a slide hammer with a 90 degree hook on the end of the shaft should get it out without damaging the aluminium.

If there was a seal under the "flange" then what you have there is not a standard arrangement. I'm thinking maybe someone replacing the seals previously could only get seals that are thinner than standard, and used the steel part of the old seal as a spacer to make up the difference.

Feetupfun - I wondered if someone had fitted a metal backed seal instead of a standard one. I have come across metal backed seals on two stroke cranks and tractor engines / transmissions. They have a higher installation / retention force than standard seals and flex less when there is a large difference between bore and OD.

I thought it was common to have a steel backing in TY250 fork seals

Many thanks for your replies - with a combination of the trusty Dremel and heat gun the metal seals have eventually come free, the problem now is that the rebate the new seal will sit in is about 15mm deep upto the washer and circlip level - I am thinking of fitting a double seal to make up the differential caused by the metal seal - is this the best solution?

Something sounds fishy with the 15mm dimension in your forks. I would have thought that standard was about 12mm. I will measure some TY250 forks in the morning.

Be aware that the circlip is not really essential unless you are going to run with air as the spring. Plenty of times when I've gone to remove the circlip there has still been clearance to the washer that was there when I fitted them - ie the seals have not moved away from their seats in use, and I use anti-sieze on seals so they are easier to get out when I change them. I also run sealed fork caps in my Bultacos that do not have seal retainers and have never had one of them have the seals move either.

Ok just pulled a seal out and measured. The distance from the seal seat to the circlip groove is 12.5mm and the seal is 10.5mm thick