Air bubbles from the Cap on SP MK2
- Thread starter Hoosier
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It has been a long time since I worked on a Mk 2, they are very simple regulators though, so there are limited things to go wrong. What is the IP doing?
Ike
p.s. If I were to make a wild guess at this point it would be to check for gouges made when changing the o-rings
Ike
p.s. If I were to make a wild guess at this point it would be to check for gouges made when changing the o-rings
If the IP is creeping up after you installed a new seat, the orifice may be damaged. This would however normally result in the second stage freeflowing to vent the excess pressure.
A leak our the cap suggests one of the o-rings is leaking - either the piston stem o-ring or the piston head o-ring. If the o-riongs have bene replaced and the problem persists, it may be that the bearing surfaces for one or the other o-ring are scratched, corroded or other wise damaged. I'd clean them thoroughly in either an ultrasound bath or a 3% to 4% solution of muratic acid (which s normally sold in greenhouses and hardware stores as a 30% to 35% solution of HCL) about 4 oz in 32 oz of water will get you in the ball park but do the math based on whatever concentration you find.
Once cleaned, inspect the bearing surfaces in the reg body and the cap carefully for damage. If you find none, install new properly lubricated o-rings and it should be leak free.
The "gouge" theory is a possibility, except there is absolutely no need to go fishing around with an o-ring pick inside a Mk 2 to remove the o-rings, so how it would happen is a bit of a mystery and I'd lean more towards salt or sand related abrasion or corrosion, particularly in the cap.
A leak our the cap suggests one of the o-rings is leaking - either the piston stem o-ring or the piston head o-ring. If the o-riongs have bene replaced and the problem persists, it may be that the bearing surfaces for one or the other o-ring are scratched, corroded or other wise damaged. I'd clean them thoroughly in either an ultrasound bath or a 3% to 4% solution of muratic acid (which s normally sold in greenhouses and hardware stores as a 30% to 35% solution of HCL) about 4 oz in 32 oz of water will get you in the ball park but do the math based on whatever concentration you find.
Once cleaned, inspect the bearing surfaces in the reg body and the cap carefully for damage. If you find none, install new properly lubricated o-rings and it should be leak free.
The "gouge" theory is a possibility, except there is absolutely no need to go fishing around with an o-ring pick inside a Mk 2 to remove the o-rings, so how it would happen is a bit of a mystery and I'd lean more towards salt or sand related abrasion or corrosion, particularly in the cap.
R
redacted
Guest
I had a Mk5 with a similar problem and, after trying the o-ring replacement with no luck, I found some irregularities (corrosion, pitting, scratches) on the o-ring seating surface on the cap. A little light metal polish on the tip of my finger rubbed them out sufficiently to correct the problem. If the problem is in the body rather then the cap, you might be able to use some polish on a Q-tip. Also, take a close look at the ambient side of the o-ring grooves on the piston.
OP
Hoosier
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Thanks for your commnets. I know MK2 is one of most easiet reg. I have about 11 MK2 and this is the first one that I have trouble after the service.
Fact:
IP: Solid and no creep at all.
O-ring: replaced with other MK2 service kits several times, but no luck. Even, I know SP O-ring spec. so, it is a big deal to replace an O-ring.
Cleaning: A whole MK2 body is cleaned in US bath. NO salt deposit..
Bearing and body inspection: I don't inspect it closely yet.. I will check it out this evening.
Fact:
IP: Solid and no creep at all.
O-ring: replaced with other MK2 service kits several times, but no luck. Even, I know SP O-ring spec. so, it is a big deal to replace an O-ring.
Cleaning: A whole MK2 body is cleaned in US bath. NO salt deposit..
Bearing and body inspection: I don't inspect it closely yet.. I will check it out this evening.
The damage is in first stage, the orifice seat seal must be replaced. The pressure is building up in second stage hoses and bubbles up or free flows. The service is necessary.
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