SP MK 25 IP

[halocline]

A leak into the ambient chamber is almost always a leak at the HP o-ring on the piston shaft, much less often from the piston head o-ring. But….there is that internal o-ring in the MK25 piston I mentioned. There are ways of determining which is the leaker, but my guess with your IP creep and noise, you just need a rebuild by a competent technician and that will fix all the problems.

 

[Johnsonsa93]

A leak into the ambient chamber is almost always a leak at the HP o-ring on the piston shaft, much less often from the piston head o-ring

The only time I see a leak at the HP o-ring is if someone forgot to use a piston bullet to install the piston and damaged the HP o-ring or if someone somehow scratched the shaft of piston which I would imagine is more difficult than damaging the tip.

Almost all ambient chamber leaks I see on flow through piston desings like the MK25 & the Atomics is from the piston head o-ring. Generally it's from corrosion build up when someone does a poor job cleaning the ambient chamber out or if someone gets debris stuck on the piston head o-ring. Where I work we have lots of black lava rock sand which is harder than brass. That lava rock sand will get stuck right on the piston head o-ring and as the piston cycles up and down it will wear a nice little grove into the metal.

Pictures attached