HW100 Leaking Cylinder

[AlBur]

Would welcome advice from resident experts.
Detachable cylinder on HW100 carbine leaking from filling port.
While filling can hear air leaking. When filling probe is removed leakage continues until zero pressure showing on cylinder pressure gauge. Leakage appears to be from the cylinder filling port

Would welcome advice on probable cause & what is required to rectify the problem, including spares required & where to obtain them.

Thanks
Cheers
Al.

[gc93]

hi, more than likely the valve and housing needs a clean and new o-ring, as to size I don't know. when mine leaked I stripped / cleaned and replaced the o-ring . I didn't have the exact same size but had one not a million miles away. main thing it still holds air. strip it and go to the nearest o-ring supplier to find the correct one or as near to. atb gc**.

[lensman57]

Sounds like the quick fill valve needs a service. How old is the cylinder?

A.G

[Pelletpinger]

If you can hear it leaking when filling, for a start it needs new o rings on the filler probe.
When you have replaced them before you do anything else give the cylinder 3 or 4 sharp blasts of air from your bottle, if there's any muck stopping the valve from seating properly this should move it and the valve should work ok.

[AlBur]

Cleaned the filling valve. Cylinder now holding pressure, no problem. However when I screw the cylinder back into the action it loses pressure. Would appear one problem solved and another created. Can the small O-ring on the action be bought separately, if so where ?? or must I buy a kit from Chambers. Also note kits advertised on the bay. Are these any good.

Appreciate some advice

Thanks
Al.

[Norfolkngood]

Looks like you need to get to a local engineers merchants and buy some bs005 o rings.

Here’s a list, I think Pok made this one up......
It's worth noting if your gun loses pressure when stored and you're unsure of the source of the air loss, all slow leaks on the action can be fixed with 5 O-rings in just 3 sizes.
12x1 Breech block (once fitted it's unlikely this will leak again)
7x1.5 Reg piston and main valve outlet
2.57x1.78 (#005) main valve inlet and internal
Use pure Silicone grease on all O-rings except Main valve internal
Tip: When removing old O-rings push a pin into the O-ring itself or use a new razor blade and be careful, don't try and dig under the seal as you may scratch the sealing surfaces.
Here's the full list of factory O-rings and the two recommended alternatives (bolded)
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

[AlBur]

Thank you for your comprehensive reply. Much appreciated !!!.

Regards
Al

[Rich]

Get a packet of BS 005 O rings, they are a common size and used in lots of rifles, I can think of the S4** series and BSA filler probes straight away.

[Benelli B76]

Cleaned the filling valve. Cylinder now holding pressure, no problem. However when I screw the cylinder back into the action it loses pressure. Would appear one problem solved and another created. Can the small O-ring on the action be bought separately, if so where ?? or must I buy a kit from Chambers. Also note kits advertised on the bay. Are these any good.

Appreciate some advice

Thanks
Al.

Do not use a small rubber O ring where the cylinder screws on the rifle. Use polyurethane, available of the bay separately or I can post you one. I have used a few of the £10 kits off the bay for 100's with no problems.

Baz

[hotversion]

Chambers kits are good its prob the first very small oring that you can see after u remove the cylinder

[AlBur]

Hi
Thanks for the info. I am hoping it is the small O ring which seals in the base of the cylinder when it is screwed onto the rifle. Have ordered a polyurethane replacement (pack of 3 !!) from the bay.

Thanks
Al.

[Rgrc29]

Can anyone give me a guide on disassembling the air cylinder?
Mine also has a leaking air cylinder, I just don’t know how to get it apart to change the valve o ring.
I’ve tried with a small vice clamping the nut surfaces and unscrewing but it flexes in the vice before anything starts moving.
Any advice appreciated.

[AlBur]

Bought 3 Polyurethane rings. Just fitted the third & still have a leak. Just not able to get a good seal. So have cured one leak & created another .
Any suggestions apart from keep changing the O ring until I find one that actually seals.

Al

[rancidtom]

Check the seating area of the BS005 O ring on the brass regulator inlet, dirt, scratches or bits of old decayed O ring can stick to it preventing the new O ring sealing. The same applies to the hole in the end of the cylinder which fits over the regulator inlet O ring, this must be clean, a drop of silicone oil or better still Abbey SM50 may help.
If these steps don't solve matters then I would suggest a full strip of the action block as there are numerous other O rings that can cause leaks, generally when one O ring starts leaking it's due to perishing through age and the rest of the O rings in the rifle are best replaced at the same time.
The rebuild guide on the HWOC website originally written by POK is very good, I would advise getting hold of a reg pressure testing gauge and a chrono for when you do rebuild it to make certain you stay legal, correct reg setting will give the maximum shot count for your gun, if it's a little out you can lose shots and have the gun under-powered or illegal.

[Scrinja]

Go on the Weihrauch Owners Club ask on there Buddy
this shortcut to get you there quick

https://www.tapatalk.com/groups/weih...r+leak#p169231

Make sure there is no air pressure at all in the cylinder before you start messing
As it will never unscrew if there is

Leave the Reg alone cure your cylinder leak first is my advice