GTA
Support Equipment For PCP/HPA/CO2 and springers ,rams => Support Equipment For PCP/HPA/CO2 => Topic started by: PakProtector on March 04, 2013, 02:21:22 PM
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hey-Hey!!!,
I did a rebuild of my Benji hand pump with a kit from Sun Optics. Biggest issue was tearing the darn thing down, followed by getting all the bits cleaned up. There was some water in it, and evidence of more( rust on steel ). Discovered that the two thin plastic shims were trashed, and when I called Sun Optics, discovered they were not required. Back together it went, with a liberal coating of Krytox 2C45 worked in well. Hooked it up and it works again...:) Woooo-Hooo!!!!
cheers,
Douglas
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The used one I just rebuilt, had hard black crud on the outer sleave (bottom section) and in the base. Carb and brake cleaner didn't work that great. Sun Optics recommended motor oil and scotchbrite. Also had some pitting on the middle sleave, near the top where the oring rests, most likely water traped behind oring.
I think those plastic shims were replaced by a "bumper" o-ring. I left them out and put one of the used oring there. Think I saw it in one of the many diagrams I looked at.
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The plastic thing-a-ma-bobs are just a waste of air space. Don't even understand what they were for. I don't think they were a "bumper". I use 2 #60 o-rings for a bumper on the stem and the stem originally had an o-ring there for that reason. Did you all get the new white o-ring that goes on the base of the stem? I talked to Sun Optics and they say, according to their info, that it doesn't need a second o-ring as a backer. I am going to test that theory. They are only .50 to replace, and I plan on buying a few dollars worth. They are probably local, I didn't see the white o-rings at Ace, Home Depot or Lowes. But they are very durable. I had to get back into my pump, the black o-ring was torn...what else is new? The new white one Sun Optics sent to me 2 week looked brand new. They are very durable. Seems the base of the stem is going to far down and the black o-ring is catching the threads and being torn. I notice this after my bro-n-law got his Condor. He had to rebuild his pump a few days after purchase. He used my pump which was in great working condition. Then my pump had to be rebuilt. He has rebuilt his pump 3 times since. And it's always a torn o-ring. When he gets up in pressure, he has to work harder to push the pump handle down. I think the He-Man downward pushing is compressing his bumper o-rings to much, hence the o-rings on the bottom end of the stem are catching the threads and tearing. And again, when he uses my pump, then I have to rebuild (twice now because of him).
So if you haven't already, then get the new white o-rings.
Joe
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I put the white one on in place of the split washer. I have a black o-ring behind it.
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I put the white one on in place of the split washer. I have a black o-ring behind it.
Good to go. I am going to order more white ones tomorrow. I will also try just using the white one only.
Joe
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Any trick to getting the nut at the bottom of the outter sleeve onto the inner one? that internal o-ring makes ir rather troublesome, and I did take a chunk out of it when I finally got it back together. It works fine for the time being, but I hate wrecking the o-ring.
cheers,
Douglas
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hey-Hey!!!,
I did a rebuild of my Benji hand pump--- (Edit)--- with a liberal coating of Krytox 2C45 worked in well. Hooked it up and it works again...:) Woooo-Hooo!!!!
cheers,
Douglas
Douglas I've been wondering about using the Krytox on the pump. Are you the first to try this? would be interested in your take after filling a couple times.
Seems like the perfect lube for this.
David
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hey-Hey!!!,
I did a rebuild of my Benji hand pump--- (Edit)--- with a liberal coating of Krytox 2C45 worked in well. Hooked it up and it works again...:) Woooo-Hooo!!!!
cheers,
Douglas
Douglas I've been wondering about using the Krytox on the pump. Are you the first to try this? would be interested in your take after filling a couple times.
Seems like the perfect lube for this.
David
I put Krytox 205 on all the o-rings that have a sliding surface, but left the sleaves dry from final clean with brake cleaner. After a couple of prod fills, it was still too tight. I went back in and put a light coat of silicone oil on all the sleave surfaces, and wiped down. Was smooth after that.
Others have reported very favorable results from Molycoate 33, also called DOW 33, and cost is significatly less.
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Thanks for the info