Dumb question about filling your tires

If (hypothetically) someone who was trying to be helpful (but not very familiar with routine car maintenance) accidentally tried using the water hose rather than the air hose at the filling station to inflate the tires, is it likely that any water actually got into the tire?

IANAphysicist, but unless the water stream is entering the valve at a pressure over the environmental pressure in the tire itself, you’re not going to get crap in there

I have never in my life seen a water hose which had the same connection/fitting on the end as an air hose, so I don’t even know how it’s possible. In any event, unless the water came in at higher pressure than the air in the tire, it’s unlikely to get any in. FTR, water pressure in the system can be quite high, depending upon how far you are from the tower and the head difference between you and the tower - I’ve seen reports on the net of people having 80psi in their homes, and some of pressures higher than that.

Not generally.

A standard/typical water/garden hose, with or without a nozzle, would not fit on the tire valve.

If the tire were flat and water was delivered through an air hose with proper attachment to fit the tire valve, water would flow into the tire. Liquids are sometimes injected into tires in the form of “Fix-a-Flat” type products using a smaller air hose and proper fitting.

So, only if water/liquid is being pumped through a proper air hose and fitting could it happen.


Tractor tires are often filled with fluid to add weight, but it’s pumped in. I don’t think you’d get much in from just a regular water hose.

FTR, IIRC tire pressure is usually in the 30’s and water pressure from a normal residential tap or hose bib should be right around 60psi, so if you could get a coupling that would fit, the water would go into the tire.

But, in reality, if you are filling tires at a gas station getting water in your tires is about as likely as getting gasoline in your grease fittings, it’s just not gonna happen with the tools (available to the public) at the gas station.

Thanks for all the responses, folks.

I wasn’t there when this happened, so I don’t know the specifics of the attempt. As Una said, I don’t recall the standard gas-station water hose having anything like the proper fitting for a tire valve, so it wouldn’t seem to me that enough of a seal could be created to force water into the valve.

It sounds like the likelihood is low enough that I don’t need to call the person involved and tell them to take the car in to have the tire in question examined.

Now, it could be the case that water, condensed in the air line, is injected into a tire. Most air compressors use a dryer to keep water out of the lines, but there is one here at my workplace that is connected directly to the compressor and it will spew a great deal of water on it’s first use after not being used for a few weeks.

That would work fine on a tractor, but at highway speed, water in a tire can play hob with balance and ride. Years ago, a friend of mine bought a new Chrysler with water in all four tires. He thought he had lost his mind until the dealer’s mechanics figured it out.

AND, even if they could crate any kind of ‘seal’ the water nozzle doesn’t have the proper hardware to depress the valve stem. I’m gonna guess your friend saw a ‘gun’ style water sprayer (which, I guess, to someone really unfamiliar with it could think it might look like it would fit), put it on the valve, pulled the lever and got soaking wet when water sprayed everywhere but into the tire.