I recently replaced the o-rings on my kitchen faucet. What's the best lubricant to use on them? I've tried vaseline and grease but neither one lasted very long.

Plumbing supply stores sell "plumber's grease" lubricant. It is specifically designed to be used on seals that operate under water and under pressure. Some high-end faucet manufacturers even supply it in box with every faucet and/or replacement cartridge.

I recently replaced the o-rings on my kitchen faucet. What's the best lubricant to use on them? I've tried vaseline and grease but neither one lasted very long.

NO! NO! AND NO!! Do not use any petroleum based lubricants on neoprene "O" rings or gaskets. Since Plumbers Heat Proof Grease is a blend of different greases don't use Plumbers Heat Proof grease either, (sorry Milo !)
The Petroleum will rot and deteriorate the neoprene. Moen includes a packet of Silicon Jel along with their new cartridges to lube the "O" rings before installing. The only safe lubricant to use on a "O" ring is Silicon, Jel
Cheers, Tom

Bump for comment!

I'm going to disagree SLIGHTLY with the experts here. You want a lubercant good for sliding. The silicon greases doesn't have it covered there in my opinion. It's good, but not great.

Although I haven't used this one, it's formulated for sliding o-ring applications.

2oz Krytox Rfe Pfpe O-ring Lubricant (442-29710) (http://www.restockit.com/2oz-Krytox-Rfe-Pfpe-O-ring-Lubricant-(442-29710).html)

It's not even close to being inexpensive.

A typical hardware store should have both. Plumber's grease, the silicon kind is good for stationary applications like threads, flat seals that you might find in drains etc.

It isn't going to be the best for sliding applications like the seal around the faucet or a single lever faucet o ring.

Silicon grease application info:

http://www.gunk.ca/prodsht-en/gr2.pdf

It isn't going to be the best for sliding applications like the seal around the faucet or a single lever faucet o ring and It's not even close to being inexpensive.
Plus costing a bundle it can also be a health hazard to use. Read the warning listed below.
Potential Health Effects
Inhalation: Inhalation of Fluorine containing compounds released as decomposition products above 290°C,
(554°F) may cause lung irritation and pulmonary edema which require medical attention. Inhalation of
Fumes or smoke from overheated or burning grease may cause polymer fume fever, a temporary flulike
Illness accompanied by fever, chills, and sometimes cough, of approximately 24 hours duration.
Repeated episodes of polymer fume fever may cause lung damage.
Skin contact: May cause skin irritation with discomfort or rash. Prolonged skin contact may cause redness and
Inflammation of the hair follicles without skin sensitization.
Eye contact: Contact with eyes will cause irritation. Blurred vision. Excess tearing.
Ingestion: Not expected under normal conditions of use.
Existing conditions aggravated by exposure: None known
See Section 11 for additional toxicological information.

Nah KISS! I'll go along with Moen and continue to use Silicon Jel. I figure the manufacturers know what's best for their products. Let me repeat my earlier statement. The only safe lubricant to use on a "O" ring is Silicon, Jel. No safety warnings with Silicon Jel. Regards. Tom

Can you use some kind of grease on plumbers o-rings

can you use some kind of grease on plumbers o-ringsGo back and read the third post down.
Do not use any petroleum based lubricants or grease on neoprene "O" rings or gaskets, It will rot the Neoprene
Purchase a tube of Silicon Jell/ Moen even includes a small packet of Silicon Jell with their new faucets,
Good luck, Tom