LeLuv pump mechanism no longer providing suction

I’ve been using a LeLuv pump with the plyers grip handle for about 6 mos. It’s similar to this…

https://s3.amazonaws.com/media.leluv.com/250212-200/gallery-amazon/leluv-premium-ultima-black-silicone-grips-hose-vacuum-pump-12-inch-gauge-275.jpg

Within the last week the pump action started getting very sluggish, and was having difficulty holding suction. So I dismantled it and found that part of the internal rubber O-ring had jumped over the piston mechanism. I put it back right, and reassembled, and it’s working much smoother now… but no suction.

Is this a common problem with these units? Anyone have it happen? What’s the fix? Replace the rubber o-ring?

And is the piston cylinder supposed to be lubricated with a light oil or not?

There’s a $10 rebuild kit that works for many of these pistol style vac pumps, or you can buy a new one for $20. I rebuilt one and restored it to working, but it wasnt 100%. I used it for a couple weeks and then got a new one.

Thanks I disassembled again, and got an O-ring at a local hardware store that seems to match. I’ll put it in tomorrow.

But does anyone know how much lubrication the O-ring/piston should have in the cylinder? Lightly oiled? Moderate or heavy? Or none at all?

Lightly at most. Especially don’t want any liquids or gels/grease on the diaphragm.

Thanks. I got it working again. If anyone cares, the o-ring size for a LeLuv pump is a #16 O-Ring (black rubber) which is 1 1/16” OD x 13/16” ID (fits Moen, American Kitchens) I got it at Ace Hardware.

The biggest PITA with dis/assembly is the metal ring needed for the 2 screws for the grip handle. It has to be squeezed/pushed just right to fit into a groove at the back of the piston cylinder.

I used only the tiniest drop of olive oil (non petroleum oil) inside the piston cylinder for lube.

The only difference now is that it does tend to lose pressure more easily. I used to be able to crank it up to 7” hg and it would just hold that pressure for a while. Now it starts to deflate over the course of about 15 secs, and have to keep re-pumping. (there’s no leak at the plastic cylinder, my penis base has a very maxed-out seal) Maybe the O-ring is still leaking in some way… or maybe the round black diaphram is leaking or not as tight as it should be? Any guesses anyone?

You are experiencing what I did. Got it back to working, but not fully. I got tired of constantly pumping it up and bought a new one. At least now you can keep your PE program going while you decide if continuing on as is will be sufficient or you choose to replace the pump or other.

Yep, that describes me here. I have to almost always keep pumping to keep decent pressure. One would think replacing an identical rubber o ring would work, but not exactly. Anyone else have any suggestions other than buying a new pump?

Try a thicker lube, maybe Vaseline…?

I use white lithium grease. Stays super slick, regardless of temperature. Doesn’t gum up like other stuff. I know it well because of its automotive applications. Works great in my pumps.

Just a followup. I eventually read up on O-rings and found that silicone grease was the preferred thing to use. So I found some silicone faucet grease at a local hardware store (Danco) and that pretty much fixed it. It’s not as good as new, but good enough that I don’t need to replace the pump. I hadn’t checked in with this thread in a while (hadn’t seen the previous post) but I also considered Lithium grease too.

The key was to use a thicker grease to seal the air in around the O-rings.