Info Servicing Scubapro MK2

[nikolay_zhelev]

Dear DR3AD,

First welcome to Scubaboard!

Your choice of Scubapro MK2 as a starter is excellent. Its simple and reliable first stage, easy to service and maintain.

Regarding scuba regulators servicing always keep in mind that this is life support equipment and extra care should be taken.

Initially try to find and read Regulator Savvy Book by Pete Wolfinger. It will give you fundamental understanding how regulators work and it’s very nice companion.

In the meantime while you’re reading the book you can try disassemble one of your MK2s and see what’s inside, get familiar with the parts.

Additionally you will need up to date schematics of the regulators you will be servicing and genuine spare parts/service kits.

To gain confidence I can highly recommend you the "Regulator Service Technician Training - Unrestricted" organized and led by @rsingler .

This course worths much more than the official brand specific courses for service technicians and it will give you all information you need to service a wide variety of regulators. Rob is great guy and he can teach you a lot of specifics regarding regulator servicing.

Regarding tools this is your starting place: Regulator Service Tech Training - Tool Splitoff

Feel free to contact me if you need any help.

Good luck!

 

[DR3AD]

Thanks, Nick, great advice. I will likely dive on one as they are freshly serviced while I learn on the other. had seen that course in another thread and was already looking at the tools / picks etc and had seen a few books on reg servicing. thanks, I will go ahead and purchase and hope this great thread stays around

 

[halocline]

I'm sure my MK2 hasn't been serviced in at least 10 years. I don't use it very much, usually for filling tires, but it is still rock solid holding IP. I'm going to put a DIN fitting on it and use it as a O2 deco reg.

If you're buying from a dive shop, I assume it will come with a 2nd stage? Maybe the R190 or something similar. If you want to go full retro, get a 109 or 108 metal 2nd stage and pair that with your MK2, you'll have a regulator that will survive a nuclear war and then any cockroaches that also survive will have something to dive with!

 

[DR3AD]

SO i pulled the trigger, the unit i bought has a tag stating it has been serviced earlier this month and has an IP of 127 PSI . does that seem low as i note in your video you are much closer to 150... maybe the spring is in need of replacement or is stronger if it has just been replaced? the IP was not disclosed prior to sale..

 

[rhwestfall]

Depends.... A couple shims (if none are currently present), and it is likely good to go....

 

[Couv]

SO i pulled the trigger, the unit i bought has a tag stating it has been serviced earlier this month and has an IP of 127 PSI . does that seem low as i note in your video you are much closer to 150... maybe the spring is in need of replacement or is stronger if it has just been replaced? the IP was not disclosed prior to sale..

Intermediate pressure should be 125psi – 145psi at 3000psi and 300psi supply pressure. Therefore probably in specs. However, if you need to bump the IP, you can most like just add a shim or two.

 

[nikolay_zhelev]

I'm sure my MK2 hasn't been serviced in at least 10 years. I don't use it very much, usually for filling tires, but it is still rock solid holding IP. I'm going to put a DIN fitting on it and use it as a O2 deco reg.

If you're buying from a dive shop, I assume it will come with a 2nd stage? Maybe the R190 or something similar. If you want to go full retro, get a 109 or 108 metal 2nd stage and pair that with your MK2, you'll have a regulator that will survive a nuclear war and then any cockroaches that also survive will have something to dive with!

@halocline ,

I recently purchased R108 in mint condition and I’m about to assemble a retro set, but unfortunately after the recent events in Europe the cockroaches are waiting on a queue in front of my closet where I store my regs

All the best!

 

[halocline]

SO i pulled the trigger, the unit i bought has a tag stating it has been serviced earlier this month and has an IP of 127 PSI . does that seem low as i note in your video you are much closer to 150... maybe the spring is in need of replacement or is stronger if it has just been replaced? the IP was not disclosed prior to sale..

It depends on what the supply pressure was when the IP measured 127psi. If it was 3000 (i.e. full tank), then that's pretty low. If it was well under 1000, that's in the range. Since the MK2 is an unbalanced piston, IP will drop 15-20 psi (I can't remember exactly) between the supply pressure of a full and near empty tank. So a good tech will set it on the high end with a full tank. I think mine is around 145 at full, and that way it doesn't drop below 125 when the tank is close to empty.

If the IP on your reg is 127 with a full tank and it was just serviced, that tech didn't do his job very well. It will work, but with an unbalanced 2nd stage it's not going to breathe very well at low tank pressures. Someone, either you or that tech or a different one, needs to add shims under the end of the spring to bring the IP up so that it stays within 125-145 psi throughout the whole supply pressure range.

There is a little problem with doing this after the fact; that HP seat now has a small groove in it from being pressurized, and you have to take it apart to put the shims in. Then when you put it back together, the groove might not align perfectly with the sharp edge of the orifice (that's the part that cut the groove) and you might get a little IP creep. It might be fine. If it was mine, I would try adding shims, and if that fixed the IP and also didn't cause creep, I'd count my blessings and dive with it. If it started creeping but the IP was good, I'd take it apart again and replace the seat, they are not expensive and they last forever.

This is why a good tech will measure the IP before rebuilding, to be able to make a good guess about how many shims to use. Sometimes the reg creeps so badly you can't really tell, but usually you can. It is a little bit of a guessing game.

 

[lexvil]

@halocline ,

I recently purchased R108 in mint condition and I’m about to assemble a retro set, but unfortunately after the recent events in Europe the cockroaches are waiting on a queue in front of my closet where I store my regs

All the best!

You are pretty close to the action, stay safe

 

[Still Kicking]

There is a little problem with doing this after the fact; that HP seat now has a small groove in it from being pressurized, and you have to take it apart to put the shims in. Then when you put it back together, the groove might not align perfectly with the sharp edge of the orifice (that's the part that cut the groove) and you might get a little IP creep. It might be fine. If it was mine, I would try adding shims, and if that fixed the IP and also didn't cause creep, I'd count my blessings and dive with it. If it started creeping but the IP was good, I'd take it apart again and replace the seat, they are not expensive and they last forever.

If you do see creep you can flip the seat over.