New MK10+ seat is loose in the seat retainer

[mr_v]

Happy Friday folks!

I got an MK10+ service kit with a high pressure seat that seems to be 0.1mm too small in the diameter, as it easily slides in/out of the seat retainer. Should I be concerned? When the reg is put together, all things seem to be tight and working well. But I never saw a set that I could remove by turning the retainer upside down.

Thank you~

 

[Nemrod]

I do not like that really. It should be a light press fit with thumb. But, there is a pressure delta there and an O-ring:

 

[happy-diver]

I love cutaway drawings or schematics or whatever they are


Hey I win it's midday Saturday here.

I've had some easily inserted aftermarket I think ebay ones, red, that if wobbled or concerned me I would boil it

 

[Nemrod]

I am off my game lately. No excuse, here is the Mark 10 instead of a Mark V.

 

[mr_v]

@Nemrod - thank you for confirming. I had the same hypothesis, as the o-ring should hold the seat in place plus there is pressure. I'll bench test the living crap out of this reg and will keep you posted.

 

[halocline]

Those diagrams don’t apply to the MK10+, as the seat retainer is more similar to the MK25, with the o-ring fitting in a groove around the side of the seat. It does not seal like the MK5 or MK10 with either an o-ring or a bushing inserted into the regular body.

I would count your blessings if the MK10+ seat is not too tight in the retainer. I haven’t worked on many, but I did recently put one together where it was a huge pain to remove the old seat, in fact I ended up drilling it out and destroying the old seat in the process. Never had that problem with my MK25s, they come out easily.

 

[mr_v]

Those diagrams don’t apply to the MK10+, as the seat retainer is more similar to the MK25, with the o-ring fitting in a groove around the side of the seat. It does not seal like the MK5 or MK10 with either an o-ring or a bushing inserted into the regular body.

I would count your blessings if the MK10+ seat is not too tight in the retainer. I haven’t worked on many, but I did recently put one together where it was a huge pain to remove the old seat, in fact I ended up drilling it out and destroying the old seat in the process. Never had that problem with my MK25s, they come out easily.

Do you have a cutaway? I lost my folder with MK10+ stuff and have only MK10.

I've rebuilt several MK10+ and prefer due to the lack of the sharp piston edge. They seem to work fine in my fleet. However, never have I ever seen a seat fallout. Are you absolutely sure that the o-ring does not against the HP seat? I am not trying to be a pain but want to prevent an unforgettable emotional event.

 

[halocline]

If you’ve rebuilt several MK10+ 1st stages, then you must know that the seat is the same as the MK25 seat, with the same o-ring configuration. It’s completely different from the MK10. I don’t have a cutaway drawing, I don’t think I’ve ever seen one. I’m sure you can find a schematic, if not for the MK10+, then for the MK20-25 and that’s the same arrangement.

 

[Nemrod]

 

[mr_v]

Ok, so mea culpa.

I was drinking beer while rebuilding the last reg and did not put the o-ring in the right place. Wow.

Btw, this is what you get for thinking "I remember how to rebuild these."