MK10 G250 Ebay special, what have I gotten myself into?

[Solacequest]

Hello all, I'm new to this forum, but very impressed with the quality of info, experience and attitude here. I just bought a SB MK10/G250 on ebay, I've been diving an old Sherwood blizzard and SB Air 2 gen 3 for 15 years and have done most of the service myself for the last 10 or so years, the 2nds are simple and has responded very well to "fiddling with it till it breaths right" I have not dug into first stages much, but can read a manual.
So my questions... before I start tearing it apart, how are these things to fix?
What am I actually going to HAVE to buy for tools, (already have a full shop of usual tools, allan keys, wrenches etc)
Where can I get a SPEC boot, looked on ebay and amazon, no luck yet. I dive in Maine. Fun, recovery and mooring work, i.e. often 0 vis and feel like a clam worm half the time burrowing through the mud. I gather that the MK10 isn't going to love this w/o the boot and some lube, or am I wrong?
MK 10 has slow leak from the vents that would be under the boot, any thoughts on likely cause (o-ring or bad seat?) before I tear it apart, run into parts I can't get, then have to get spanked in the wallet by the dive shop for showing up with a bag of parts.
O.K. I'll stop with the questions now, (for now) Any advice would be much appreciated.
OH, one more found a bunch of "annual service kits" on ebay from 10 to 50 bucks, are they all made equally, is there anything to avoid?

 

[Keith.M]

A good place to look for manuals: http://www.frogkick.dk/manuals/

 

[redacted]

Hello all, I'm new to this forum, but very impressed with the quality of info, experience and attitude here. I just bought a SB MK10/G250 on ebay, I've been diving an old Sherwood blizzard and SB Air 2 gen 3 for 15 years and have done most of the service myself for the last 10 or so years, the 2nds are simple and has responded very well to "fiddling with it till it breaths right" I have not dug into first stages much, but can read a manual.
So my questions... before I start tearing it apart, how are these things to fix?
What am I actually going to HAVE to buy for tools, (already have a full shop of usual tools, allan keys, wrenches etc)
Where can I get a SPEC boot, looked on ebay and amazon, no luck yet. I dive in Maine. Fun, recovery and mooring work, i.e. often 0 vis and feel like a clam worm half the time burrowing through the mud. I gather that the MK10 isn't going to love this w/o the boot and some lube, or am I wrong?
MK 10 has slow leak from the vents that would be under the boot, any thoughts on likely cause (o-ring or bad seat?) before I tear it apart, run into parts I can't get, then have to get spanked in the wallet by the dive shop for showing up with a bag of parts.
O.K. I'll stop with the questions now, (for now) Any advice would be much appreciated.
OH, one more found a bunch of "annual service kits" on ebay from 10 to 50 bucks, are they all made equally, is there anything to avoid?

You have a very good regulator there but that balanced piston 1st does have some drawbacks in cold, silty water. Unfortunately, SPEC boots are on the store shelf right next to the hens teeth. The leak you describe is one or both of the o-rings that seal the piston. These are also the o-rings that are vulnerable to being compromised by silt in the water. You could give it a try without packing the ambient chamber and see how long it goes before the silt get to them. It may be quite a long time. If and when they do fail, the failure mode would be a slow leak as opposed to a catastrophic failure so you would be able to finish that dive and repair before the next trip. If you are using air rather than nitrox, you could probably get away with packing it with silicone and see how long it lasts. You could probably even come up with your own cover to reduce the water/packing exchange.

You might want to check with vintage double hose (Vintage Scuba - Vintage Scuba Gear at Vintage Double Hose) for service parts. You might even talk to Bryan about making SPEC boots. He is producing a few scubapro rubber parts already and might be interested in adding that to his line. Scubapro still produces service kit for those regs but finding a source that is not ridiculously overpriced can be a challenge.

No special tools for the G259. You will need something to unscrew the ambient chamber and something to unscrew the HP seat retainer on the Mk10. Special tools are available (VDH may have them) or you can come up with work-arounds. The proper special tools tend to work with less chance of marring the finish, if that matters.

 

[herman]

Now awap, you know there is one specialty tool he has just gotta have.
Seriously, you don't have to have any special tools but I make an oring insertion tool (awap tested and approved ) that will make your life easier. I also make a spanner to remove the HP cap. PM me if you are interested.

 

[Couv]

You can (and should) download the manuals at vintagedoublehose.com. It would also behoove you to download the file named "scubapro poppet changes" from the same location.

Vintagedoublehose.com-->Manuals and Catatlogs-->Continue-->BLPEN163-->ScubaPro Schematics. Download the following files: ScubaPro poppet changes, G250 Vintage annotated schematic, 109 250 adjustment principals.

Herman's piston stem o-ring insertion tool can save you a lot of frustration. See my review here:

http://www.scubaboard.com/forums/do...tools-mk-5-mk-10-piston-stem-o-ring-tool.html

 

[scubafanatic]

You have a very good regulator there but that balanced piston 1st does have some drawbacks in cold, silty water. Unfortunately, SPEC boots are on the store shelf right next to the hens teeth. The leak you describe is one or both of the o-rings that seal the piston. These are also the o-rings that are vulnerable to being compromised by silt in the water. You could give it a try without packing the ambient chamber and see how long it goes before the silt get to them. It may be quite a long time. If and when they do fail, the failure mode would be a slow leak as opposed to a catastrophic failure so you would be able to finish that dive and repair before the next trip. If you are using air rather than nitrox, you could probably get away with packing it with silicone and see how long it lasts. You could probably even come up with your own cover to reduce the water/packing exchange.

You might want to check with vintage double hose (Vintage Scuba - Vintage Scuba Gear at Vintage Double Hose) for service parts. You might even talk to Bryan about making SPEC boots. He is producing a few scubapro rubber parts already and might be interested in adding that to his line. Scubapro still produces service kit for those regs but finding a source that is not ridiculously overpriced can be a challenge.

No special tools for the G259. You will need something to unscrew the ambient chamber and something to unscrew the HP seat retainer on the Mk10. Special tools are available (VDH may have them) or you can come up with work-arounds. The proper special tools tend to work with less chance of marring the finish, if that matters.

Vintagedoublehose sells MK 10 1st-stage kits for $ 15.00

 

[Solacequest]

Thank you! found all the manuals there, sweet.

---------- Post added June 23rd, 2015 at 10:18 PM ----------

Awap, Thanks for the info, I see what you mean about finding the spec boots, hens teeth I'm looking at a pile of lobster claw bands and thinking...(I'll give VDH a call before I get too drastic). and to all of you, you have some great advice. Scubafanatic, I found the kit on VDH and all the manuals, on frogkick. Herman, I was looking at an o ring tool on ebay, (was planning on chucking up a chunk of HDPE in the lathe but your's looks sweet on Couv's review, the spanner would be great too, the chrome is perfect right now and I'd like to keep it that way, I'll PM you if my adjustable won't do the trick. I really appreciate all the advice, sorry it's taken so long to get back too you, you guys are quick!

 

[DiveGusto]

When you get it all apart don't forget to check the piston tube edge that seats against the puck. If it has a ding an new seat won't seal. Run your finger nail around it to check, any hang up means it needs to be polished out or replaced. GL