disassemble a cressi spg to repair?

[xrcjdx]

i have what i assume to be a mini cressi spg (unlike the spg s for sale now, the pressure indicating dial goes to 400 bar, not 350). it is blowing bubbles from inside the boot. would like to disassemble and replace the air spool (assuming the leak is coming from there). a couple of problems: first, this gauge/boot rotates freely on the end of the hose (as it has since day 1), and moves slightly up and down. when under pressure it is tight. so i am not even sure this attaches the way i assume. second, there appears to be no way to remove the boot. there are no screws or any other visible means of assembly. if nothing else, i'd like to salvage the hp hose. my guess is that this thing started to leak with under 50 dives on it. have been using it as back-up, but would either like to use it on a bail out bottle or give to a friend. the bubbles are annoying at least, and an early indication of a failure at worst.

from cressi (newer gauge - mine tops out at 400 bar):

Technical characteristics

• Case material: chromium plated brass
• End scale: 350 bar or 5000 psi
• Face: luminescent with coloured sections
• Pressure release valve: incorporated
• Instrument diameter: 50 mm
• Height of case: 14 mm
• Total instrument height: 17 mm
• Hose diameter: 11 mm

thanks in advance - would post to the cressi manufacturer forum but can't seem to find it -

rc

 

[diversteve]

Try immersing it in hot water then flexing the boot and popping it loose.

The hose should come with it as you remove it - unscrew the connection and pull it back thru the boot.

At least that's what I've seen work on other brands. No exp. with Cressi.

 

[scoobydrew]

Without having the SPG in my hands I can only advise you based on previous experience with other regs.

From what you have said I would bet that the issue is your spool O rings which will need replacing. To remove the boot all you have to do is put it in warm water to soften it up then by holding the hose close to the attachment to the gauge with one hand and the end of the boot with the other you need to kinda bend the gauge out of the main hole then slide the boot down the hose out of the way.

Use 2 wrenches most likely 9/16 to unscrew the gauge from the hose - if the gauge is plastic then do not try to unscrew the hose by holding the gauge in your hand and wrenching the hose as this could well break the gauge. Once separated you will see the spool either in the gauge or the hose, it needs to be removed without using something like a pair pf pliers which will damage the spool. Once you have it out, take off the old O rings and swap them out for new ones, use a bit of silicone to stop the rings drying out and I was always taught to put a little grease on the threads before reattaching. Put the lot back together but leave the boot off, pressurize the regs and drop the gauge in a glass of water and look for bubbles, if there are none then put the boot back on.

 

[xrcjdx]

yup that did it!! but now there is a little water inside the gauge. we'll see what happens when i pressurize it.

thank you both very, very much.

ralph

 

[redacted]

yup that did it!! but now there is a little water inside the gauge. we'll see what happens when i pressurize it.

thank you both very, very much.

ralph

Where, exactly, are you seeing water inside the gauge? Water inside an SPG can result in erroneous readings and complete failure.

 

[halocline]

Someone probably should have warned you to pressurize the leaky SPG before submerging it in hot water. If air is leaking out the spool, water can leak in when it's not pressurized. Take the SPG off the hose, take the spool out, and see if you can drain the water out completely; although I think if it's water visible on the gauge face, under the plastic lens, it's not coming from the spool at all, but I could be wrong about that.

You'll also want to push some air through the hose by connecting it without the SPG on to the first stage, pressurize, and let some HP air blast through to completely dry out the hose.

If all of this fails, don't despair, just get a brass/glass SPG with no boot and consider it an opportunity for an upgrade.

 

[emoreira]

The possible problem are the small o-rings in the spool.
Yes, without pressure, the SPG will move up and down and rotate.
Water inside the SPG, if you have a cylinder available, connect the hose without the SPG to the first stage and open very little the valve of the cylinder to remove the water from the hose.
Clean inside the holes where the o-ring goes.

 

[redacted]

I should have been more specific. If the water you see is coming out of the pressure inlet, then you should not have a problem. But if you can see water through the face of the gauge, it is just a matter of time before it fails.

 

[Scared Silly]

If you are seeing water inside the gauge that is from the lens leaking not the from the hose connection leaking. As AWAP noted it will soon fail because of corrosion.

 

[xrcjdx]

the water slowly drained or evaporated out of the gauge, as it was standing stem down. will carefully pressurize with a new spool/o-rings and submerge to see if the glass is sealed. the good news is this is a backup (it did after all start leaking at a young age), but would of course like to save it if possible.

thanks to all who chimed in - i learn almost as much from this board and the people here as i do actually diving.

rc