Long...MK10 plus ?

[buddhasummer]

Usually the MK10s that have been converted to plus are shiny chrome with a satin seat retainer. I don't think I've ever seen a satin MK10, but that doesn't mean they don't exist.

Simon, I would put a shim under the spring on the opposite end from the piston, clean up and re-use the centering bushing, and then use as many of the thinner shims as you need on the seat retainer. I would also polish the end of the piston shaft with some micromesh, maybe starting around 2400 grit. If you're only getting 5 PSI change in IP from full to empty tank that's very good for a MK10.

Thanks Matt. It's possible it's a Japan only model, I've seen a few oddities over here. I cleaned up the center bushing and cleaned the piston with some 3200 micro mesh. So don't use either of the white ones I have piston edge spring end? ,that would mean the spring is in direct contact with body, just one on the bushing under the spring and then whatever need be on retainer?

 

[rhwestfall]

So one sitting against plastic bushing? How many did you have on the seat retainer?

none

 

[buddhasummer]

none

That's strange as everything I've read says a MK10 PLUS is shimmed at seat retainer cap.

 

[rhwestfall]

yep. As I said, it was an abomination. I believe it was a converted 10, and parts were left in it, that is why I think that is what you have.... With used, who ever knows.... that is part of the fun!

 

[buddhasummer]

Probably should have left it alone given it was functioning well within spec, but curiosity got the better of me and I have no idea when/if it was last serviced. Bob, you are right, fun it is...

 

[buddhasummer]

I am still curious what this 10-500-118 part looks like though, I'm going to try and order one. Why is it necessary and why doesn't mine have one?

 

[rhwestfall]

It is a shouldered off white/clear washer that is cut to easily press in and out of the body...

 

[buddhasummer]

It is a shouldered off white/clear washer that is cut to easily press in and out of the body...

Then I definitely don't have one. I've put in an enquiry as to availability, but given mine functions fine without it I guess it's not absolutely necessary, in fact I guess the two white washers I have on top of the spring despite not being on any schematic also work just fine. An exact science it is not. No reason to believe it won't work just fine even if I assembled exactly the same way with the same parts in the same places and a new seat.

 

[rhwestfall]

the "bushing" is a wiper, and should go on above the plastic hood on the piston, riding on the piston shaft inside the spring. Again, IIRC, something for "icing"...

 

[rhwestfall]

FWIW, the seat is the same one as the MK-20/25, and as the piston is not a knife edge, I'd put money on it that it doesn't need replacing. If you do anyways, keep the old one as a spare. The longevity of those seats is remarkable.