Author Topic: Benjamin Hand Pump repair kit (Read 1439 times))

Bicycleman · « **on:** February 08, 2022, 03:48:15 PM »

Because I use my hand pump to fill my PCPs, I guessed that this thread would be okay here.
I already called Crosman and was informed that they do not have the hand pump repair kits. I could order all items separately. Nope!

Who is a good source for the Benjamin hand pumps repair Kit?

(My pump has been a good tool for the past eight years; and I don't want to give up on it yet.)

Mr Fluffy Tail · « **Reply #1 on:** February 08, 2022, 03:54:56 PM »

usually all you need are the orings .. ebay im sure has kits with the updated viton or whatever it is seal .. if your main tube is pitted you can probably flip it .. check youtube on how to disassemble .. and dont torque things down hard so you can regularly take it apart to dry it out and lube it .. ~30w silicone oil is good to slather everything up with ...

CraigH · « **Reply #2 on:** February 08, 2022, 04:26:22 PM »

Used to be Sun Optics, but not seen on their website now.

toddbrat · « **Reply #3 on:** February 08, 2022, 04:54:28 PM »

This should be all you need:

Bicycleman · « **Reply #4 on:** February 08, 2022, 05:15:17 PM »

Quote from: Mr Fluffy Tail on February 08, 2022, 03:54:56 PM

usually all you need are the orings .. ebay im sure has kits with the updated viton or whatever it is seal .. if your main tube is pitted you can probably flip it .. check youtube on how to disassemble .. and dont torque things down hard so you can regularly take it apart to dry it out and lube it .. ~30w silicone oil is good to slather everything up with ...

Thank you for your reply. It is appreciated.
I have been through this pump several times. The main tube was/is pitted. I have used the 00 steel wool on it AND flipped it too. In the video I watched last, the guy said someone was not recommending the MOBILE 1 'Full Synthetic' motor oil in just about any weight. However, I will continue using the full Silicone oil I have.
I will check out the EBay site. Had not thought of that. Wish me luck.

Bicycleman · « **Reply #5 on:** February 08, 2022, 05:17:13 PM »

Quote from: CraigH on February 08, 2022, 04:26:22 PM

Used to be Sun Optics, but not seen on their website now.

Thanks, Craig. I will give them a phone call - if necessary.

Bicycleman · « **Reply #6 on:** February 08, 2022, 05:21:06 PM »

Todd, I see in the link "Capitan O-Ring". I have bought from them before - and thanks for reminding me. I will give them a call and see what the kit directly from them will cost.

fatmike · « **Reply #7 on:** February 08, 2022, 07:14:06 PM »

I've used the captain o ring kit. Had everything I needed except grease. Pump is going strong. It's not used as much now with a compressor but anyways.

fatmike · « **Reply #8 on:** February 08, 2022, 07:20:22 PM »

I saw a picture of a blown up pump. It was assembled with motor oil. Looked like it exploded at the base and through the hose. Pretty scary to me. I'll use silicone grease just to be sure I'm not in danger. Maybe the pump that burned did something incorrectly because I read that motor oil was the way these were assembled in the first place. Not sure how correct that is. I guess it's time to research for knowledge on this.

Bicycleman · « **Reply #9 on:** February 08, 2022, 09:08:11 PM »

Mike, I am planning to use the Silicone grease and oil when I reassemble my old tool.
I looked at the Capitan O-Ring kit, and found that it didn't include the two small plastic washers found in the upper part of the pump. Mine are mostly used up and need replacing. If I can't find them anywhere, I will have to try and make my own.
Anybody have suggestions on making the plastic washers?
Mike, thanks for your reply.

Greg_E · « **Reply #10 on:** February 08, 2022, 10:41:37 PM »

Pretty sure the owners manual says use only silicone, anything that can combust with a supply of air and extreme pressure should be avoided!

nervoustrigger · « **Reply #11 on:** February 08, 2022, 11:44:33 PM »

The late Duane Sorenson is the designer of the Benjamin pump. He worked for Sun Optics up until his untimely death (stroke). I spoke to him a few years ago about getting my pump working again. He helped with my O-ring question and went on to advise that I clean everything well and lubricate it with a good synthetic motor oil. I did as he recommended and used the pump for several months before the final stage O-ring wore out again, but during that time I read that I was dancing with the devil on each successive pump stroke. So when I went in again to replace the O-ring, I thoroughly washed everything with a degreaser to remove all the old oil and used 30W silicone oil thereafter.

Back_Roads · « **Reply #12 on:** February 09, 2022, 08:56:10 AM »

Yup some people have no clue how a diesel engine runs

TrpDSgt · « **Reply #13 on:** February 10, 2022, 12:15:51 AM »

Is there a good video or detailed instructions on the rebuild. I have bought the Captain o ring kit and I'm not have any luck with my Benjamin. I have replaced all the O Rings, but I get nothing. The two clear plastic washers seem to be deformed/imprinted, could this be my issue? Also, I watched one video that mentioned putting liquid in it? My did not have any liquid in it when I took it apart? Thanks for the help.

Bicycleman · « **Reply #14 on:** February 10, 2022, 08:30:38 AM »

Dwayne, I have no idea what the plastic washers are for. But I did make one to replace the badly worn washer in my pump. I used the lid from a little spice take-out container from Carrabba's. [It is the one for the spice mix they give you to mix with olive oil and dip the bread in.] I used a pair of fingernail scissors to cut the round edge; and a bullet casing to cut the center hole. Two washers are used at the top of the pump - between the o-ring and the handle end of the pump.
The Benjamin pump does NOT have any liquid in it - pay no attention to any video that mentions liquid in a pump. Those pumps were around for a while; but I haven't seen anything about them lately. I think they were the 'Chinese made' variety.
I saw a good YouTube video recently. The guy is wearing orange gloves to keep his hands clean. (Gloves are optional.) He does use motor oil as a lubricant. This is not recommended in high pressure pumps. The oil might cause combustion/explosion inside the pump. <--- Not a good thing!
Keep everything as clean as possible. Use Silicone grease and oil during the reassembly. The grease keeps the o-rings lubricated. The oil goes on sliding tubes and shafts.
Good luck with your rebuild. [Post your results.]

CraigH · « **Reply #15 on:** February 10, 2022, 08:56:00 AM »

The Sun Optics kits (now apparently NA) did have the white plastic washers. I will keep mine safe for future use.

Bicycleman · « **Reply #16 on:** February 10, 2022, 09:09:19 AM »

Craig said: I will keep mine safe for future use.
Good idea. If they are in the pumps, they must have a function.

CraigH · « **Reply #17 on:** February 10, 2022, 09:44:52 AM »

Quote from: Bicycleman on February 10, 2022, 09:09:19 AM

Craig said: I will keep mine safe for future use.
Good idea. If they are in the pumps, they must have a function.

Maybe I should auction them (2) on ebay like a Crosman 600, or 100, or Sheridan.

Bicycleman · « **Reply #18 on:** February 10, 2022, 09:57:50 AM »

I have seen some strange thing on EBay.

TrpDSgt · « **Reply #19 on:** February 11, 2022, 03:19:44 PM »

I am at a loss. I have torn the pump down about ten times. I get nothing. I don’t know what I am missing? Is there anyone that I can send it to to repair?

Thank you to our advertisers!

Benjamin Hand Pump repair kit

Author Topic: Benjamin Hand Pump repair kit (Read 1439 times))