Mk10 IP creeps after serviced

[jamescjy]

Hi guys, recently I bought a couple of mk10 from eBay and this was my first time servicing SP regulator. Prior to this I have rebuilt plenty of conshelf.. long story short my questions are does SP regulator tend to lock up IP slower after fresh service? Will they creep lesser over time?

Video below is what I got after fresh service, new seat, new oring.. I tried to feel for any nicks on the knife edge piston but it seems ok for me. I also tried to polish it with chalk but still the same result.

So care to input any opinions diyer and SP expert? Should I get NOS piston? Many thanks!

 

[guruboy]

Why is your IP bouncing back so slowly? Hard to tell where the creep starts.

 

[redacted]

Yes, that looks really bad. Defective seat or defective piston. If the problem is the piston, it should be visible under magnification. I would inspect both very closely. If the piston looks OK (that much creep is not a minor flaws) I would be tempted to try a different seat, even an old one just to see what it does.

 

[abnfrog]

id say wrong hp seat but check the knife edge with a jewelers loop

 

[jamescjy]

thanks for all the reply!

i too thinking should be the piston problem, since i changed second seat and its the same case

so where can i buy NOS piston besides eBay?

 

[halocline]

I have several NOS MK10 pistons, happy to sell you one.

That's quite a bit of creep, I suspect it's a combination of the piston and seat, and maybe your HP o-ring is a bit soft or not lubed well enough. That could cause some friction on the piston shaft and slow down the lock up. You might want to verify that the o-ring you used is either a 85 or 90 duro, and is well lubed (you can put lube on the piston bullet and shaft before installing the piston)

I inspect the pistons with a jeweler's loupe. Lots of times I have found flaws that I couldn't see without magnification that caused some creep. Nothing like what I'm seeing on your video, though.

Edit: I see that you're in Malaysia. Send me a PM if you'd like and maybe I can send you some other parts as well, that way shipping won't kill you for just the piston. Awap and I bought a large box of assorted NOS scubapro parts, and I have several MK10s.

 

[rhwestfall]

maybe your HP o-ring is a bit soft or not lubed well enough

or nicked....

 

[jamescjy]

I have several NOS MK10 pistons, happy to sell you one.

That's quite a bit of creep, I suspect it's a combination of the piston and seat, and maybe your HP o-ring is a bit soft or not lubed well enough. That could cause some friction on the piston shaft and slow down the lock up. You might want to verify that the o-ring you used is either a 85 or 90 duro, and is well lubed (you can put lube on the piston bullet and shaft before installing the piston)

I inspect the pistons with a jeweler's loupe. Lots of times I have found flaws that I couldn't see without magnification that caused some creep. Nothing like what I'm seeing on your video, though.

Edit: I see that you're in Malaysia. Send me a PM if you'd like and maybe I can send you some other parts as well, that way shipping won't kill you for just the piston. Awap and I bought a large box of assorted NOS scubapro parts, and I have several MK10s.

that will be great! i was thinking earlier on i might have to look for another mk10 to salvage since i also need a yoke knob for my second mk10, any chance u might have that as well?

i am planning to sand abit on the piston with sandpaper tomorrow and see how it goes. if it still does not work i will pm you to purchase

 

[Couv]

Dressing a metal orifice

 

[jamescjy]

Today i tried to troubleshoot further and swapped out the new seat with old HP seat, turns out the problem was the seat afterall IP lockup was fast and precise and only creep less than 5psi

So now my questions are how does a new seat resulted in creeeping that way and will they creep less after more dives?

Where do you guys source your HP seat? is this a good one from eBay?

Scuba Regulator High Pressure HP Seat Part First Stage Dive A242 | eBay

edit: btw really appreciate all the reply and helps given in this thread!