Question Skipping 1st stage Maintenance?

[Pearlman]

Ok I’ve put the MK19Evo aside until the diaphragm chamber tool arrives. I do have a vice and soft jaws and mallet but I don’t want to risk it as I rarely use hand-tools in my life and lack the muscle memory - having become a softy keyboard warrior over the last few decades.

Edit: Hmmm I need to reconsider using a vice at least for the initial shock loosening of all the parts … good idea! Thanks for the tip @happy-diver !

Now I opened the MK25Evo and I found only a single silicone sleeve on the piston! Did I forget to put it back in during the classroom session? What happens if I don’t use the missing piece and rebuild it?

I also made a nick on the piston side of the body while trying to remove the ring(23) even though I used a brass tool….

I hope it is ok and safe functionally with that little nick?

 

[Pearlman]

Hmm ok an older video mentions two piston sleeves for all mk25 batches after 2006 but the service charts shows just a single sleeve..my bad.

@rsingler In the MK19Evo Teardown video you mentioned a 32mm spanner for the dry chamber but my vernier shows 30mm … why is that?

 

[admikar]

I don't know if it's just me, but seems you would be better off letting someone else servicing your regs.
You managed to make 3 potentially costly mistakes already.

 

[Pearlman]

Two (mistakes) not Three! The sleeve isn’t missing it was for an older reg series... The nick isn’t on the piston knife edge and it shouldn’t affect the seating, so hopefully it’s ok …

 

[Mobulai]

What happens if I don’t use the missing piece and rebuild it?

I found an H75p (non evo mk25) like that, it had IP of 160+ (can’t say it was the root cause)
But the piston stem oring was knicked (probably the reason for the bad creep, probably caused by the missing ring, or slamming the piston onto it)

 

[Mobulai]

Two not Three! The sleeve isn’t missing it was for an older reg series...

Was just gonna say, you seem to have both
Older ones also had 2 not 3

Edit: ah , you’re talking about mistakes not aligning rings

Edit 2: my bad, you did mean the white one? i meant the 2 black ones that go around the oring

 

[Mobulai]

my vernier shows 30mm

This looks like a ~32 to me

 

[Pearlman]

Stupid of me not to eyeball the vernier correctly. Yeah single sleeve for new MK25s… it’s on the service chart but I went blindly by the video since it is so good otherwise…

Edit: ah , you’re talking about mistakes not aligning rings

Edited for clarity. Beginners mistakes! Getting a grip on things now slowly… hopefully no more…

 

[Mobulai]

Re: the missing ring

So I finally got to open it up, I started by looking at the piston blunt nose after uncapping, just by eye I could spot 2 glistens of light that seemed like bumps..
View attachment 867088View attachment 867092
I then go on taking out the seat, rings and piston shaft oring, under all the caked dry cristo and to my surprise.. only one out of the 2 rings came out, and the piston oring had a score mark so perfect it looked like a lp seat View attachment 867091
I don’t know how on the 1st test pressurized it had a „slow“ creep, that thing should have shot up like crazy without the top ring (#15 on schematics), but maybe that scored oring helped relief some of that IP to the ambient chamber as you guessed @Johnsonsa93 , just in the weirdest possible variation
View attachment 867089
the cap looked very clean, but along with the piston head were very sticky, almost tacky, the piston orings also seemed to to be in shape

I’m glad whoever sold it to me didn’t have a burst hose or something equally horrible and lived to (not) tell (me) about it.. I am lost in the sauce so I move on

Time to break the micromesh and try my hand at this awesome guide by @rsingler buried at the bottom of my bookmarks , the only time I did something similar was on an mk10 sharp knife edge — ending with a low but acceptable IP (need to find me a shim), but I’m fairly optimistic about getting it to lock up, easier to dress and raise ip given the smooth edge and adjust screw

 

[Pearlman]

^^^Scary! The piston base already has a bump by design, I wonder what it does exactly since it’s a flow through piston…

So many loose Allen keys I thought I would have a 7/32 key to remove the swivel but unfortunately not! I have multiple 5mm and 6mm. but nothing 5.5mm… ran around a few shops nobody has 5.5mm either. Thankfully Amazon has them with 4hr delivery… waiting …