My wife has a 2007 Honda Jazz 1.4 DSi CVT approaching 50K miles. A friend noticed there was some fluid on the floor from the car.

I've seen the drips myself. The fluid was clear, odourless as far as I could tell and the drips were cool to touch with the engine up to temperature. After jacking up the car and removing the plastic under tray I've found these two hoses which looks like drainage / overflow.

My questions are:

  1. What's the purpose of these hoses?
  2. Do I need to take any corrective action?

Hoses: Two hoses

Drips: Fluid leak

From the location of the drips on the tray, I believe the source of the fluid is from the left hose on the first image. AC has always been on when we've seen the drips.

1 Answer 1


The fluid you're seeing is pure water.

The purpose of at least one of the hoses (which, I can't tell) is to let the water condensed in the AC system fall to ground. An air conditioner reduces the temperature of air, which has moisture. Colder air can hold less moisture, and therefore, it reaches its saturation point when cooled, and the water condenses.

There are two ways to get rid of the condensed water:

  • Let it fall to the ground via a pipe (the way used in car AC systems)
  • Move it to the AC condenser (which is named for condensing the working fluid, not for condensing the water; for water it's doing the exact opposite). The AC condenser is hot, and the heat can be used to evaporate the water. This is the way used in portable one-unit air conditioners, where the AC condenser is below the AC evaporator.

Cars are used outdoors, and it's not dangerous to let the water fall to the ground via a pipe. Indoors, letting the water fall to the floor could cause water damage and possible mold growth.

  • 1
    Two notes. 1) in high humidity areas it wouldn’t surprise me to see a cup of water per 15 minutes of run time if control is set to normal / outside air mode. 2) You will see less water AND get better fuel economy AND better cooling if you stay in MAX A/C mode (Recirc setting). In that setting you will be cooling dry air.
    – zipzit
    Jul 30, 2019 at 14:32

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .