Hill Mk4 hand pump issue?

[Guest]

I have been using the Hill Mk4 hand pump for a couple of months now. I bought it new from PA. Before that I used Xcisco (I think thats how it's spelled) hand pump. I have noticed the hill pump will feel different some strokes. It is hard to explain but sometimes the handle feels harder to pull up like it is pulling in more air. Sometimes it feels too easy to push the handle down and the handle usually pops itself up an inch or two on each stroke unless I hold down on it for a full second. At the top of the stroke it will sometimes want to pull itself down unless I hold it up for a full second then it will stay. Almost like a check valve is sticking. I'm not sure if these things are normal and just have to deal with them or is there someway to make the pump better to operate? My chinese pump used to do almost the same things from time to time which is why I'm not sure if it's the norm. The hill pump is a lot smoother to use than my other pump (which is to be expected for the price) and has never failed to work but I just feel it could be better.

Does anybody use the Hill Mk4 and does your pump act the same way? Any suggestions on what to do with it? Thanks!

Just a side note.. I always let the pump cool off for atleast 15 minutes after 40 strokes so I don't think I have over heated it and damaged any seals.

 

[Peskådot671]

Might be a dumb question to ask you but do you apply the silicone grease that came with the pump to the shaft?

 

[Guest]

Yeah I have used that and it doesn't make a difference. It only lubes the shaft and outermost o ring I believe. Thanks for the suggestion though.

 

[Chachoze]

Well my Benjamin pump had behaved that way from the start. It seems more noticeable when I am pumping a little to fast but if I slow it down it doesn't seem as bad. I also will make sure the handle is all the way down before closing the relief valve to keep the pump shaft protected when its not being used.

 

[Stone02]

Mine, a model without the moisture trap, failed completely; the shaft was coated from rust after each pump stroke. Use a Q Tip, to check for rust in the air outlet of the pump and your pcp air inlet.

 

[Bizill]

I have the Hill Mk4 and mine exhibits the exact same behavior. I like to go a bit slower. I stop one or two seconds at top-most and bottom-most strokes. Give air time to do what it wants to do. For me it behaves a bit better and doesn't act that way as you describe as much. Nothing wrong with it, but it does feel odd. Slowing it down some helps. Plus it stays cooler.

 

[Guest]

Thanks for the responses guys. I have found the same thing Bizill, if I pump slowly and pause at the top and bottom it works fine. I know they say to pump slow and to pause at the top and bottom of each stroke anyway but I have to go extra slow. Anyway it has been getting the job done so I'll just order one of the (over priced) rebuild kits to have on hand in case it decides to die on me.

 

[Guest]

I have heard that the Hill MK3 is a more reliable pump than the newer MK4 that a lot of people have been reporting issues with. Maybe in the future I will try to find a used one in nice condition.

 

[Ag5643]

I purchased one 2 months ago. Worked good for about 3 weeks. Now needle jumps, down stroke feels like it is doing nothing, will lunge up about halfway, then is an absolute bear to come up all the way. Know I need a rebuild kit, but I have had a cheap ole Benji pump for 4 years, hasn't failed yet. In fact I'm so pissed at the hill, I'm using the benji because I can't bring myself to buy the seal kit for the almost $300 hill mk4

 

[Guest]

I think one of the big problems is that they assemble these pumps and then they sit for sometimes years on a a shelf until someone buys it and in that time the seals have dried out and become weak, Just an assumption unless their QC has taken a dump.