Pump gauge is not working as expected

Hello all!

I apologize if this is a repeat of another thread, but I was unable to find one that matched the specific problem I was having.

I bought this pump: https://www.ama … /dp/B00KKW33B6/ - (Leluv Ultima Men’s Vacuum Enhancement Pump Black Protected Gauge Handle 9 x 2.125 inch Cylinder)

It took me a long time to attach the hose to the pump, but now at least that part of it works.

Here is what I’m seeing so far:
- When I create a seal at the end of the hose without the cylinder, I am able to get suction and the pump gauge shows the pressure created as expected.
- When I attach the hose to the cylinder and attempt to create a seal, either with my member inside or on some other flat part of my body, then use the pump, the pump gauge does not change as expected even though I can feel and see the pressure on my body.

I thought it might be the o-ring, but the o-ring seems completely fine. Perhaps there is some other way I could test the o-ring? I also considered that perhaps I need a silicone cylinder sleeve, but the instructions didn’t mention anything about that. Other than that, I have no idea what is happening here. I’m excited to start pumping, but I don’t want to move forward without a working gauge. Please advise on what to do next! Also, if anyone in particular has experience with Leluv products, perhaps you could share your experiences with them?

Thank you so much for your consideration and have a great day!

Hey HypeTrain,

I wouldn’t pump without a sleeve, myself. The difference in comfort and seal quality is night and day.

If you are indeed having an O-ring issue, you could compensate by putting some silicone grease on the fitting threads themselves. It could also be over tight or under tight. Generally once the O-ring begins to squish is enough. If it totally deforms it can’t seal.

To rule out the fitting, you could put some duct tape over the tube entry, and apply vacuum. See if it holds. If it does, the leak is at your body seal point.

On Amazon, this is the most common sleeve sold with that tube combo.

https://www.ama … /dp/B00725WCL6/

Thank you, 114life!! Super helpful answer!

Are those sleeves, like the one you linked, interchangeable between different cylinders? I would be surprised if they were not, but I thought that I should be clear.
Also, by silicone grease, are you referring to silicone lubricant (I.e. For humans)?

Thank you so much for helping me out!

I never use a sleeve or seal.

You have confirmed the hose and pump are holding vacuum, which leaves 3 locations:

1) the hose-cylinder connection of the two fittings
My experience is this connection sometimes doesnt snap together properly and so does not allow vacuum to build in the cylinder: i.e., it looks connected but isnt. I assume it could also be a source of the leak. Hold/press the hose into the cylinder tightly and see if it makes a difference while pumping. Check the o ring on the male fitting for damage.

2) the female fitting into the cylinder
Confirm the fitting is screwed in tight, but don’t overtighten. I’ve had them so loose you could remove with your fingers. I usually go finger tight then slightly more. Also check the o ring to see if it is in good shape. A part of it can slide up and out during the tightening. As 114 said, dont want the o ring to deform too much.

3) base of the cylinder connection to the skin
Dry skin, pubic hair, piece of cloth or anything between skin and cylinder can cause a seal failure. I always lube up before pumping. Trim your pubes is also good practice.

One of more of those have always been the problem whenever I couldn’t pull a vacuum easily.

Also note that many tube sellers don’t give the diameters of their products; those always seem to be 2-1/2” in diameter and have problems getting a seal without some kind of gasket or sleeve.

Not silicone lube, silicone grease. It won’t pull through the threads as easy. Like one might use on a spark plug boot. It’s safe on plastic, acrylic, and rubber. Don’t use a thread sealer or gasketmaker type silicone, you may eventually need to replace the fitting without damaging the tube threads.

It’s available at autoparts stores for about $3 for a .5oz tube. If this is all you’re going to use it for, would last for years.

Silicone grease can also be used to lubricate your quick connects and pump parts. Although, in the pump, I prefer either lithium grease or DOT 5 brake fluid.

This is precisely what I use.

https://www.ore illyauto.com/de … ne+grease&pos=0

That’s a National Pipe Taper thread; note “taper.” That means it’s a self-sealing thread in most cases, as long as you crank it down hard enough. But a taper is a wedge, and it tries to expand the hole when you turn the fitting in. Lubricating the threads makes it eady to get tremendous force across the threads. If you’re lucky, the threads will strip. If you’re not lucky, the mating part - in this case, the end of the tube - will split open.

*Gently* tighten the fitting until it doesn’t leak and doesn’t try to unscrew itself during normal use. You can always snug it back up if you have to, but if you crack the tube you’ll be sorry.