Scubapro MK25 serviced, now problem...what should I do?

[triggerman365]

I recently took my MK25 to a LDS for annual service (after 3 years and 250 or so dives). The tech is relatively new. After it had been serviced, I hooked it up and pressurized it and a loud squeal sounded. I then took it back to the Tech. and he removed the cap and used an 5/32 hex wrench to "tighten" the seat retainer. He pressurized it and...no squeal. I took it out several days later, pressurized and...super loud squeal. I took it back in and he replace a washer he said was bad, even though all that had been done during his service. Well, okay, off for another try. I pressurized it today and...yup...same squeal.

So, I'm done with his services. But I live in the middle of the Pacific and really just want it serviced and tested with confidence that it is right.

Any suggestions on where I can mail it for service?

 

[Pullmyfinger]

Where in the Pacific are you located?

 

[triggerman365]

Saipan

 

[Pullmyfinger]

When I was living on Guam, I used to have Randy at Micronesian Divers Association (MDA) service my Scuba Pro regs.
I would see about getting your regs to Randy. You will end up with a better result.

Cheers,
Mitch

 

[tstormdiver]

Usually the squeal is due to inadequate lubrication of the piston stem O-ring. Unfortunately, to fix it requires most of the 1st stage to be taken a part.

 

[Zung]

I think the HP o-ring is nicked: I reported a similar case here.
Tell your "tech" to replace it.

 

[buddhasummer]

Usually the squeal is due to inadequate lubrication of the piston stem O-ring. Unfortunately, to fix it requires most of the 1st stage to be taken a part.

Yes, exactly the issue I'm having with my Z2 and was told the same.

 

[halocline]

Did it squeal when you breathed on it, or was it a loud constant squeal when you pressurized it? The piston o-ring squeal is usually when breathing, as it's caused by vibrations of air moving fast through the piston resonating. If you turn on the air and you get an immediate noise that doesn't stop, it's likely a leak in the seat retainer. In the MK25 there's an extra o-ring for the external IP adjustment.

Or maybe the HP o-ring on the piston stem is just leaking. If you want to try to investigate it, fill up a tub, take the plastic boot of the seat retainer end, pressurize and submerge. Look closely for the bubbles. If they're coming out the holes in the ambient chamber, piston stem o-ring, if they're coming from the seat retainer, there's your problem.

 

[triggerman365]

Did it squeal when you breathed on it, or was it a loud constant squeal when you pressurized it? The piston o-ring squeal is usually when breathing, as it's caused by vibrations of air moving fast through the piston resonating. If you turn on the air and you get an immediate noise that doesn't stop, it's likely a leak in the seat retainer. In the MK25 there's an extra o-ring for the external IP adjustment.

The squeal is constant, steady, squeal, that began when pressurized.

Or maybe the HP o-ring on the piston stem is just leaking. If you want to try to investigate it, fill up a tub, take the plastic boot of the seat retainer end, pressurize and submerge. Look closely for the bubbles. If they're coming out the holes in the ambient chamber, piston stem o-ring, if they're coming from the seat retainer, there's your problem.

I will try this test today with a pony tank.

Thanks for the thoughts.

---------- Post added April 13th, 2013 at 09:34 PM ----------

Well I pressurized it again with my pony tank and NO squeal at all. So, I am wondering, the tank I was using yesterday was "jammed" to 3400 psi. My pony was less than 3000 psi. Could an over filled tank with higher pressure cause the squealing?

 

[tstormdiver]

Well I pressurized it again with my pony tank and NO squeal at all. So, I am wondering, the tank I was using yesterday was "jammed" to 3400 psi. My pony was less than 3000 psi. Could an over filled tank with higher pressure cause the squealing?

Not likely. I dive frequently twin steels filled to 3600 psi & use MK25's on them all the time & they don't squeal/