Air leaking when bottles screwed in.

[slurpysam]

Hi Guys,
On my rapid 12/200, as soon as a screw the bottle back on after a fill there is air leaking out of the pellet probe, when engaged into the breach the air comes out of the barrel, any ideas?
It has a KevG reg, but the rest is standard. And oh my is it accurate, before this happened
Thanks in advance.

[Squinty]

hi, its either
a) valve body o-ring
b) too much hammer pre-load
c) damaged valve- sealing face or bent valve stem

[slurpysam]

Thanks Squinty,
I've ordered an o ring kit, have never had to service this rifle and had it from new, fired hundreds of thousands of pellets, so probs due a service .
Its been losing air very slowly over the last few weeks, when I went to put the cylinder back on full it absolutely pi$$ed out, it was sounding funny the other night out rat bashing.

so the best thing you think is a strip and clean etc?

[Squinty]

just the basic service - o-rings and check the condition of the valve.
If necessary buy a complete valve- body and stem (rather than just a stem).

[angrybear]

Thanks Squinty,
I've ordered an o ring kit, have never had to service this rifle and had it from new, fired hundreds of thousands of pellets, so probs due a service .
Its been losing air very slowly over the last few weeks, when I went to put the cylinder back on full it absolutely pi$$ed out, it was sounding funny the other night out rat bashing.

so the best thing you think is a strip and clean etc?

As Squinty has said, It's the exhaust valve leaking, the black plastic one that the hammer strikes the shaft, because that's the assembly which transfers air from the chamber to the barrel.

It might just be normal age related wear & tear, or it might be that some "home tuning" has been done to increase the power, like a stupid heavy hammer spring & too much preload which has caused a bent valve stem.
"Sounding funny" might have been the first sign of a bent valve stem dragging allowing excess air behind the pellet as it leaves the muzzle.

TBH if leaking past the valve is your only issue & you don't know what you're doing, I'd change the complete valve assembly but not disturb the reg to change the O rings if it's set by Kev & still good,
if it's been over sprung or the adjuster screwed up tight back it off/ refit the correct spring.

[slurpysam]

Hi Angrybear,
Nah its still shooting bang on 11.4 and uber consistent, no need to be a messin, all the parts, apart from the reg are all what it came with, not having had to mess with something thats worked like this rifle has is one of the joys of it. I also and FAC .22 rapid and a Mk 2 .25 impact, this is my barn rifle for pigeons and rats, and I get a great shot count with the reg.
Ill be needing to look through the service posts to familiarize myself with the strip down again.

[slurpysam]

Is there a sticky anywhere for the strip down and rebuild etc?
Just getting used to the layout.

[slurpysam]

Ah found em.

[Ca_Varminter]

Here is the Problem area on the Valve-Stem/body....


Problem areas...
Valve-body sealing face
The Valve-body O-ring/s
Also the Valve-stem itself. Roll it to see if it straight!!

Good Luck!
Stuart

[slurpysam]

So Started my strip down removed valve body,blanking plug, grub screw and fired out the exhaust valve, i have the black acetate one in mine, so the service bumf says replace it? it also says there is an o ring on the body, mines not got one. Now I assume it had one at some time? so wheres that gone? or am im missing something here?
Any advice would be really handy.
regards.

[slurpysam]

Can I also add that my valve stem is the two o ring type, but only has one on the rear of it, is this the norm too? Valve stem seems nice a straight.

[slurpysam]

So sorry to be bombarding you guys with this barrage of probably stupid questions, the strip done only goes so far, do i need to remove the bolt for a service to be carried out on it?
And where can we buy the replacement black exhaust valve? or is it a steel one from the likes of TR Robb?

[nevadacowboy]

Dr Bob is your man.  He has his own thread on this forum. This is link to his website and a link to his thread on the forum..


Shop | Dr Bob (drbobsgunbits.com)

https://rapidforum.co.uk/forum/index.php?board=27.0

[Ca_Varminter]

The Black Acetal one's are better for general use....
Wow.. the Large O-ring on the valve-body is what seals the system!!!
Yes it is Needed...
You should not have 2 O-rings on the valve-stem only one...
On the groove towards the hammer side!!!

BTW There are No Stupid Questions... We are Here to Help!!

Stuart

[Ca_Varminter]

KevG or Dr Bob has the Quality Spares!!!!
But if your Valve-body is OK...
No scratches or gouges in the sealing face...
It should be OK... NO Need to Replace!!!

Stuart