Discovery Pump Freezing

[Gunby]

What are your experiences with the Discovery hand pump?

The one that came with my .22 Discovery froze in the extended position after only 5 fills. I sent it back and got a replacement from Pyramyd Air.

The replacement will occasionally freeze in a partially extended position. However, it seems to fix itself overnight and works the next day. What's with that!!!

I am very good at following instructions and am using the pump properly. In fact, I pretty much "baby" it and, pump slowly, let is rest 15+ minutes after 3 or 4 minutes work, and limit the pump strokes to 100 or less between cool offs. The pump has never felt warmer than my big toe.

Help!

[melloroadman]

If you bleed the pressure off does it free its self or stay locked .Marvin

[longislandhunter]

Try rotating the handle 360 degrees several times.....

I've heard that sometimes corrects the problem....

Jeff

[DanoInTx]

Gunby - 3/22/2009  12:47 PM

....and limit the pump strokes to 100 or less between cool offs......

100 strokes between cool-offs is a little excessive, most people stay between 20-30 strokes per cool-off.  I don't own a Discovery pump, but with my old FX pump 100 strokes would be enough to fill a Discovery from empty to 2000 psi most likely, does it really take 100 strokes to top it off, or are you shooting it totally flat between refills?  I know some of the newer pumps say you can pump them forever without hurting them, but my guess is that if you got it hot enough you could be making the o-rings stick inside the tube.  I think my arms would break off if I pumped for 100 strokes at a time, haha!

[gamo2hammerli]

With my Hill pump....I just pump it 40 to 50 strokes and then take a 5 minute break....and another 40 or 50 to fill up my PCP's depending on how low they are to begin with.  Usually when my PCP's are in the 100 BAR level....I start to fill them.

[Gunby]

Thanks for the feedback guys. In answering some of the thoughts you brought forward:

- When I bleed the pump it does not cure the problem and the pump remains frozen
- I'll try the idea of rotating the handle 360 degrees when it happens. That sounds interesting.
- In addition to my Discovery, I also fill Airforce tanks which go to 3,000 psi. That is when I may pump 100 strokes.
- Maybe I'll limit my sessions to 60 pumps and see what happens.
- When doing 100 pumps, I stop at the top for about 1 second and at the bottom for 1 second. That means I pump about 3 1/2 minutes before stopping for 30 minutes to a couple hours.

[spark22]

I'm nursing my second benji pump,my frist pump did the same thing and froze up on it's 3rd fill and crosman replaced it.If you had it under 90 days send it back.When mine finely goes out I will try to rebuild it but will more than likely get a Hill pump anyway because I will be getting more pcp guns and will need a good pump that can be rebuilt.

[araz2114]

Check this out...

http://www.network54.com/Forum/581291/thread/1237857522/add+another+pump


Chris

[Gunby]

Interesting. While the phot he links to is a Hill pump, I gather he is using it to help explain how to work on the Discovery pump. I may give it a try if this 2nd pump takes a dump after the warranty period.

I understand Hill pumps are designed to be rebuilt by users. They even sell a rebuild parts kit. Sounds like a great idea.

[araz2114]

They are exactly the same inside... as far as I took it apart.

Chris

[waunderin]

well, i did get about 50 or so pump ups out of it. thought maybe i got a good one, but then again, nothing lasts forever. i'll dig into it tomorrow.  john

[Gunby]

Well, it did it again last night. I put 75 pumps into my Talon SS tank then bled the pressure and moisture from the bottom of the pump. All seemed well.

While going to put it away, I lifted it by the handle and it extended. When I went to push it down, it was stuck about 10 inches from the bottom. You could force it down with your body weight, but it would spring back up once you let go. The pump was useless at that point and would not work.

As before, the next morning the pump worked pretty much as it should. What the heck is going on? Is it possible one of the three chambers (3-stage pump) is trapping air that it won't release for some reason? I do not know how these devices work, but when you push on the stuck handle it feels like you are pushing against a full beach ball and the trapped air, of course, has no where to go.

[Gunby]

Well, I sent Crosman an email describing the problem. I included a link to this thread. I'll let you know if they respond.

[waunderin]

i spoke with crosman on the phone a couple of days ago. the gal tried to make it sound like they were not aware of any problems with the disco pumps. they will replace the pump, but after talking with her, and thinking about it, replacing with another disco pump, will not solve the problem. it will only extend it into some time in the future. i have plans for a spring vacation, where i can shoot at any distance, so i guess i should be glad that the pump broke now instead of then. it could of ruined the whole trip.
   so far, as i see it, i have three choices, buy another brand of pump, like the hill, with a good reputation for durability, buy a scuba tank and fittings, or toss the disco and go back to springers. i'm still thinking about it.   john

[melloroadman]

I hope you take one of the first two choices that you mentioned . If you chose the last and want to trade the disco for a good RWS 46 .177 P.M. me . Marvin