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My HW40 has dramtically lost power
Although their is some resistance as I close the gun (probably around a third of what there used to be), now there isn't enough power to move the pellet - there is just a faint sound of escaping air. It went from firing normally to marked decrease in resistance when closing/decrease in power to not even moving a pellet within the space of 4 shots.
Any thoughts on what might be the cause gratefully received
ATB
Jon
Even a stopped clock is right twice a day
I assume you have been putting the odd drop of oil on the piston to lubricate the o-ring?
If you have and it is still losing pressure then it may be this: The Beeman P17 has a common fault which some HW40s may share - the O-ring on the piston catches on a burr around the inlet hole, and eventually it gets worn enough to lose pressure.
It's an easy fix - loosen the grub screw at the end of the piston where it is attached to the frame, tap the hinge pin out and remove the piston. If you need to replace the O-ring then apparently that size is available from B+Q. Of course chambers also stock it.
Get a bit of very fine wet'n'dry and deburr the inlet hole inside the cylinder, then replace o-ring and piston. You should have no more problems after this.
Good deals with these members
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Good advice from eyebull. If you can hear air escaping from breach seal end, its probably the valve seals. The piston leak tends to be a gradual one, and tends not to be heard. The repairs are easy to do and I replaced all my seals (3 in all) and can be bought from B&Q. You need "Plumb sure" mixed o'rings 1/16" pack for valve, and Plumb sure 3/32" pack for piston. This will help. my.tbaytel.net/~coopers@tbaytel.net/HW40Review/ My repairs were done on Beeman P17s but its the same gun essentialy.
Last edited by peteswright; 13-11-2012 at 08:28 AM.
Knowledge is knowing a tomato is a fruit. Wisdom is not putting it in a fruit salad.
Registered User
Many thanks eyebull and peteswright - that is really helpful - if you or anyone else knows of some pictures or a video showing the strip and reassembly that would be the icing on the cake! (I am not very knowledgeable about the parts..and not too practical once I do know what's what - but without a spring inside to fire bits around the living room, I might just have a go!)
ATB
Jon
Even a stopped clock is right twice a day
Hi Jon, can't find a link at the moment but I'll take a sequence of pics for you when I get home. Nothing to be scared of with this one, it's pretty straight forward.
Good deals with these members
Registered User
That would be brilliant - many thanks eyebullOriginally Posted by eyebull
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