Can you repair a marauder fill pump?

[jjpeters4]

Hi guys, i been looking at the xs60c pcp, reason being is obviously the price. So my brother says he would just give me his marauder fill pump.however it needs fixed, heres what it does, when you go on the downstroke it acts like theres a blockage somewhere, its real stiff like the air dont want to go in the gun, then the pump rises up on its own, more than likely due to the pressure in the pump.....can this be fixed? If so i have a free pump...lol

[AmBraCol]

What condition is the tube in?  You can get a complete reseal kit for these for around $20 or so.  They're fairly easy to take apart and mostly just need to be cleaned up, regreased (use ONLY silicone grease like you can get at a dive shop) and work fine afterwards.  If you've got a bad tube (due to rust from neglect) then it can be harder to get going again.

[Talan]

My Benjamin pump acted exactly as the one you are writing about.  A clean up and lube that I found on you tube made it work as new.  They are very easy to disassemble.  Just be careful not to nick your packings when you put it back togeather.  Be really stingy when lubing.

[CraigH]

Parts for the Benjamin pump are available from http://sunopticsusa.com.  The seal kit is $3.00.

[jjpeters4]

I dont think its going to be rusty in the tube, my brother is pretty particular about his stuff....so it sounds like something simple..

[45Bravo]

Sun optics built the Benjamin pumps.

Yes the seal kit is very cheap.

Like you I was given a used pump, doing exactly what you described.
 since I didn't know the history of the pump I sent it to sun optics for a factory service.

Send them the pump and $29 (if I remember) and you will get you a factory reseal and return shipping of your pump to your door.

Duane Sorenson there would be your point of contact.

He is always willing to talk airgun equipment.

Great people, great customer service.

[AmBraCol]

Parts for the Benjamin pump are available from http://sunopticsusa.com.  The seal kit is $3.00.

Thanks, Craig.  I've been needing that info for a while.  Just  put in an order for parts to rebuild a pump I was about ready to toss.  A former owner never did any maintenance on it, the main tube is shot.  We'll see how long 'til parts arrive, then hopefully it'll be up and running again.  I like my Winbest by Barska pump better, but the Benjamins are good enough for a Discovery - especially when properly maintained.

[AmBraCol]

I dont think its going to be rusty in the tube, my brother is pretty particular about his stuff....so it sounds like something simple..

Josh, first things first, just take it apart, wipe it down, reassemble with a smidge of silicone grease in the appropriate places.  An o-ring pick helps to get them out, just go one at a time and take a good look at them, clean them, lube them and reinstall.  These pumps are fairly simple machines, just disassemble carefully keeping parts organized and reassemble in reverse order.

[CraigH]

The thing with these various lower cost pumps (and for that matter everything anymore) is sample-to-sample quality and variation.  I first bought one of the non-Benjamin style models and would have kept it but a plug blew out of the gauge along with the fluid so I sent it back.  It also had the air intake at the top.  I bought the Benjamin for ease of installing a home-made desiccant system (as seen elsewhere on GTA).  My variation is attached.

[Monkeydad1969]

On the pump center rod, there is a small hole, around that is an o-ring.  If it is the older black o-ring, they degrade from the built up heat and the grease that is used is way to thick.  It will clog that little hole and cause the issue you are having.  The link below shows the rod, the hole is on the brass end.

http://sunopticsusa.com/pump-center-rod-p-23/

Sun Optics has been including a new white o-ring that doesn't degrade.  I have not had to rebuild my pump since.  I now use my tanks and have been for over a year, but will sometimes use my pump.  In the link below, you can see the white o-ring.

http://sunopticsusa.com/oring-seal-kit-p-oring/

Joe

[FuzzyGrub]

Your symptoms match for the inner o-ring failure.  Do as Joe says above. 

Use silicone grease on fixed sealing o-rings.  The ones that slide against the a tube you should use silicone oil.  Wipe those surfaces down with the oil.