Scubapro mark V

[Couv]

DA and company,

I think Trident now has generic low pressure seats for the BA poppet. See page 26 item A148 go to http://www.tridentdive.com/international.htm to down load a copy of the catalogue. Note that the index is in the rear of the catalogue.

I don't have access to a price sheet, but I can not imagine the price difference being that much, but it is always good to have an alternate parts source. Besides, almost any dive shop could probably order one if needed.

RE IP change, that is one of the advantages of having an adjustable second stage.

c

 

[oceancurrent]

Folks,

I am working on rebuilding two Mark V regs (with 5 LP ports each - need help disposing of them). All in all, it is going well. However, I am having trouble taking out the turret screws. I just don't have a suitable tool for the job and am worried about scratching the piston barrel. In your experience what is the best way to get the screw out?

Also, I am trying to figure the safest technique for taking out (while possibly reusing) the inner o-ring in the piston shaft. It looks like a bear to take out.

Last but not least, where can I find new HP seats for the regs? Also, I am looking for the original service manual for the reg.

Please help!

 

[redacted]

Folks,

I am working on rebuilding two Mark V regs (with 5 LP ports each - need help disposing of them). All in all, it is going well. However, I am having trouble taking out the turret screws. I just don't have a suitable tool for the job and am worried about scratching the piston barrel. In your experience what is the best way to get the screw out?

Also, I am trying to figure the safest technique for taking out (while possibly reusing) the inner o-ring in the piston shaft. It looks like a bear to take out.

Last but not least, where can I find new HP seats for the regs? Also, I am looking for the original service manual for the reg.

Please help!

I'm not real sure exactly what you are talking about when you say "turret screws". LP port plugs come out with an allen wrench (5/32 or 4mm). Use an LP hose in one of the LP ports to hold the turret (swivel) if necessary. If you have a version with an environmental kit (a thicker ambient chamber cap) then environmental plugs also take the same allen wrench.

I use a double hook pick to remove the HP piston o-ring. You want to avoid scratching the downstream seating surfaces. And you also want to replace that o-ring rather than reuse it. BTW, removing that o-ring is easy compared with installing it.

The Mk5 takes the same HP seats as the Mk10.

If you PM me with an email address that will take an attachment, I'll send you a Mk5 schematic. If nothing else, it will give us a common parts terminology. I've never seen a tech manual for a Mk5.

 

[oceancurrent]

I'm not real sure exactly what you are talking about when you say "turret screws". LP port plugs come out with an allen wrench (5/32 or 4mm). Use an LP hose in one of the LP ports to hold the turret (swivel) if necessary. If you have a version with an environmental kit (a thicker ambient chamber cap) then environmental plugs also take the same allen wrench.

I use a double hook pick to remove the HP piston o-ring. You want to avoid scratching the downstream seating surfaces. And you also want to replace that o-ring rather than reuse it. BTW, removing that o-ring is easy compared with installing it.

The Mk5 takes the same HP seats as the Mk10.

If you PM me with an email address that will take an attachment, I'll send you a Mk5 schematic. If nothing else, it will give us a common parts terminology. I've never seen a tech manual for a Mk5.

What I meant was the turret retainer, which in my case is hexagonal with a round hole in the middle. This is the part giving me a headache.

Seat for MK10 - check. How about the o-rings? If I am to replace the O-rings, which part kit should I seek?

What is the best way then to install a new o-ring in the recessed groove in the piston shaft?

By the way, the springs are covered with the remnants of some sort of red paint. I wonder - was this purely decorative or is is something essential (such as corrosion deterrent)?

 

[DA Aquamaster]

Are you referring to the flow through retainer that holds the LP port turrent on the swivel cap? If you the best approach is to get a used 11/16" deep well socket at the local pawn shop for $1.00 and then grind the end of it flat to eliminate the radiused edges. If you don't remove them it will slip as the hex head on the retainer very thin.

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Removing the o-ring is fairly simple, but use a brass o-ring pick to avoid scratching the groove tha the o-ring sits in.

Installing one is actually fairly simple as well. Poke the new o-ring in the hole long ways far enough to press the upper edge into one side of the groove. Hold that end in the groove with lateral presure using the the side of a straight o-ring pick, then from the other end (the HP seat end) push the other end of the o-ringup toward the groove with a suitable long skinny but flat on the end object like the long end of a 5/64" allen wrench. As you push it upward it shoudl roll into the groove. Sometimes they twist a bit and you make have to nudge it in place with the side of the o-ring pick, but it is something that is easy to do with just a bit of coordination and practice.

Peterbuilt (Scubatools.com) also makes a special tool for it, but I find using that to be a lot harder than the method described above.

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The Mk 10 and Mk 5 seats are identical, so everything in a Mk 10 service kit will work except the piston head o-ring. The piston head is the same diameter as the Mk 15, 20, 25 so a piston head o-ring from one of those kits would work as well.

Tusa also made the Mk 5 under license until fairly recently and Tusa seats will work as well. Tekna also had a licenced copy but with a different seat retainer and taller seats - and Tekna parts are hard to find anyway.

If it still has the older flat seat, it can be flipped and reused - unless someone has already done that.

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The parts kit for the Mk 5 is part number 10-105-045

 

[redacted]

Be very careful with that turret bolt (swivel retainer). Although Scubapro did an upgrade to stainless steel, most Mk 5 that I find are still brass which can be easily damaged by too much torque. The recommended torque is only 35 to 45 inch pounds which is quite light. Also, inspect that bolt for any sign of damage from over torquing. Unfortunately, new ones are no longer available from SP and can be very hard to come by.

The Mk10 kit has the HP piston o-ring that will work in the MK5. The Mk10 piston o-ring is a 2-017 and the Mk5 uses a 2-022. The Mk5 also need a 3-015 o-ring on the yoke nut that is not included in the Mk10 kit. I use mostly aftermarket o-rings as the kits only include a couple of the o-ring that might be needed.

 

[oceancurrent]

Thank you, guys! I will look around for an MK10 service kit. The piston head o-ring looks quite thick to me, so I feel it would be relatively safe to reuse: clean, inspect with jeweler's lens, lube, and reinstall. If I find defects in the o-ring, I will look for MK15,20,25 kit.

By the way, where can I find the torque specs?

 

[redacted]

Torque specs are usually shown on the SP schematics as values in [xx]. My Mk5 schematic also shows a spec of [275-325] inch-pounds for the yoke nut. I found a spec of 44 inch-pounds on a Mk10 schematic for port plugs which should be good on all their brass 1st stages for plugs and hoses. BTW, I like to stay on the low side for the swivel retainer (35 in-lb) and for the yoke nut (22 ft-lb / 260 in/lb).

 

[oceancurrent]

Folks, what is the best method for separating the HP seat on MK 5 first stage from the seat cap with minimum damage? There seems to be a tiny hole in the back of the cap, but I am not sure if it goes all the way through to the seat. I tried sticking a needle in it but it hit a hard surface and didn't do much... Many thanks!

 

[oly5050user]

Folks, what is the best method for separating the HP seat on MK 5 first stage from the seat cap with minimum damage? There seems to be a tiny hole in the back of the cap, but I am not sure if it goes all the way through to the seat. I tried sticking a needle in it but it hit a hard surface and didn't do much... Many thanks!

hold it up to a tank valve-tiny hole facing the valve,and let it rip!! should blow it out to remove easily.Do not use a needle asit woud damage seat and you not be able to reuse the side that is untouched.