Hw100 query

[AC all day]

Hi guys,
I have a HW 100 that's leaking air down the barrel( without pulling the trigger!) I have just pumped it up and you can hear it escaping down the barrel..... Any ideas which seals to replace please??

[bighit]

Try Blackmax on here. He is a whizz with the HW100.

[rancidtom]

Hi guys,
I have a HW 100 that's leaking air down the barrel( without pulling the trigger!) I have just pumped it up and you can hear it escaping down the barrel..... Any ideas which seals to replace please??

If it is from the barrel then the exhaust valve isn't sealing properly. It may have dirt on the sealing face or it may have corrosion damage. It's unlikely to be an O ring if it is actually leaking into the barrel.
There are loads of threads and you-tube vids how to strip and rebuild the HW100 but you really need a pressure testing gauge to reset the regulator after a rebuild and a chrono to check your results. I would recommend a full rebuild replacing every seal, you may be lucky and just have to clean the valve face but it may be damaged or corroded enough to require replacement along with the exhaust valve spindle.

[Willenium]

Valve not sealing against the block. Will need to be lapped back in but when you remove the valve block, the o-ring will likely need to be replaced as well.

[Blackmax]

Hi guys,
I have a HW 100 that's leaking air down the barrel( without pulling the trigger!) I have just pumped it up and you can hear it escaping down the barrel..... Any ideas which seals to replace please??

As previously said, it’ll be the valve, it’s most likely to be uneven wear which is common on them, this
can be rectified by lapping - I believe HW100 Tuning did a tutorial on how to do this.

You’ll only need to replace one O ring and that’s the one that seals the valve block to the main block, replace it with a 12 x 1mm rather than the Weihrauch standard size as they crush on fit.