Leaking HW100

[Cicero]

Had this from new but not used for a little while. Last week I took it out of the gun cabinet and filled up to 200BAR in readiness for use this week. When I came to get it I found all the air had completely gone.

This has never before happened so I would appreciate some advice as to the possible culprit. Could it be the tiny seal that fits over the end of the air cylinder where it joins the action ...?

[thisisdonald]

theres youtube videos on detecting the leaks on hw100.
as a process of elimination, I would first fill the bottle and remove it, mix up some weak fairy liquid /water.. just enough so it can bubble and paint it all over both ends of the cylinder and see if it bubbles anywhere.
if that is good, I would put a balloon over the barrel and check for leaks through the regulator and transfer port.
if you watch the vids, its pretty easy job

[Artfull-Bodger]

the two regular culprits are
1st, the o ring on the brass spigot where the cylinder screws in.
2nd, the firing valve cap o ring.

as noted above there are plenty of how too videos online or on the forums, it's easy enough to sort.

[Cicero]

Thanks gents. I will have a look.

[threelander]

could also be breach block seal

[Shedder]

"Artfull-Bodger
the two regular culprits are
1st, the o ring on the brass spigot where the cylinder screws in.
2nd, the firing valve cap o ring."

I've had two leaks on mine and both were the cylinder spigot. On the second ocassion the new O-ring I fitted also leaked, so if you change the o-ring and it still leaks don't necessarily assume that it is leaking somewhere else

[Cicero]

"Artfull-Bodger
the two regular culprits are
1st, the o ring on the brass spigot where the cylinder screws in.
2nd, the firing valve cap o ring."

I've had two leaks on mine and both were the cylinder spigot. On the second ocassion the new O-ring I fitted also leaked, so if you change the o-ring and it still leaks don't necessarily assume that it is leaking somewhere else

That's really helpful sir. I would have automatically assumed the fault would be elsewhere if I fitted a dodgy replacement ...

I've had a shufti at the YouTube video(s) and will be ordering some seals in th every near future.

Thanks again

[Cicero]

Oh, just one more thing: should I add a little lube to the seals? I have done whenever fitting seals on other rifles but I noticed the guy on the YouTube video didn't use it.

[thisisdonald]

I use plain vaseline. Just enough to make them shiny. Rub some between your fingers, then rub the seal between them. In the aircraft industry we assembled fuel governors using petrolatum, which is basically vaseline.

[PETER R]

hmm ive had this problem for a while gunsmith also had issues trying to get seals from hull cartridge and weirauch , had it done but its still not like it used to be .

[ferrets123]

my hw100 started to leak,,,it turned out to be the seal in the air tube,,sent it to Darrin at xtx air,,never leaked since,,top guy to deal with.

[Artfull-Bodger]

hmm ive had this problem for a while gunsmith also had issues trying to get seals from hull cartridge and weirauch , had it done but its still not like it used to be .

You can buy BS005 O rings online which fit better than the factory ones for the cylinder spigot.


Here's the full list of factory O-rings and the two recommended alternatives (in brackets)

O-ring HW 100, 37.1 x 1.6 Cylinder clamp 2682C
O-ring HW 100, 15.6 x 2.5 Barrel clamp 2682B
O-ring HW 100, 32 x 2 Magazine 2603A*
O-ring HW 100, 13 x 2 Adaptor A 2704
O-ring HW 100, 2.57 x 1.78 Adaptor B 2703B

O-ring HW 100, 3 x 1.5 Valve stem 2655D
O-ring HW 100, 12 x 1.2 Breech block main (12 x 1) recommended 2658
O-ring HW 100, 5.5 x 1 Breech/probe seal .22 2659A*
O-ring HW 100, 4.5 x 1 Breech/probe seal .177 2659A*
O-ring HW 100, 4 x 1.5 Probe buffer 2618A*
O-ring HW 100, 2.57 x 1.78 Main valve inlet 2665D
O-ring HW 100, 7 x 1.5 Main valve outlet 2666
O-ring HW 100, 2 x 2 Main valve internal (2.57 x 1.78) recommended N/A
O-ring HW 100, 7 x 1.5 Regulator piston 2668
O-ring HW 100, 10 x 1.5 Tension adjuster (sometimes omitted) 2672
O-ring HW 100, 8 x 1.5 Barrel 2679

[Cicero]

I thought before I replace the seals I would unscrew the tube, take it off the rifle and see what happens. I filled to 200 bar and left it for five days. It now reads 160bar.

I'm slightly confused now because, as per the original post, I filled the rifle as usual only to find it completely dumped all the air soon afterwards. I'm guessing in this case that the relatively slow leak on the detached tube is compounded by the need for a seal replacement on the rifle. Or, and this is where I could do with some advice, the slow leak on a detached tube is normal and would be rectified by replacing the seal(s) on the rifle as then the air from the leaking tube would have nowhere to go?

Any thoughts greatly appreciated.

[Benelli B76]

hmm ive had this problem for a while gunsmith also had issues trying to get seals from hull cartridge and weirauch , had it done but its still not like it used to be .

Get my HW 100 seal kits off the forbidden zone for 10 quid. The most common seal that leaks on the 100 is polyurethane in these kits, best material for the job.

Baz

[Bladerunner too]

I thought before I replace the seals I would unscrew the tube, take it off the rifle and see what happens. I filled to 200 bar and left it for five days. It now reads 160bar.

I'm slightly confused now because, as per the original post, I filled the rifle as usual only to find it completely dumped all the air soon afterwards. I'm guessing in this case that the relatively slow leak on the detached tube is compounded by the need for a seal replacement on the rifle. Or, and this is where I could do with some advice, the slow leak on a detached tube is normal and would be rectified by replacing the seal(s) on the rifle as then the air from the leaking tube would have nowhere to go?

Any thoughts greatly appreciated.

The slow leak on the tube while off the gun is NOT normal (again relatively easy fix) but you are correct in saying that if the tube is on the gun an all other seals fine then there should be no leak.