Vehicle Leak Identification

My truck developed a slight leak recently. It wasn't catastrophic, but it was a bit hard to locate the source. Over this weekend, though, the truck it developed a very noticeable whine on startup and particularly while steering.

A whining/groaning sound on steering is a dead giveaway that the problem was in my power steering system. What that problem was, however, could vary in cost and difficulty from under $20 and completely pedestrian to several hundred dollars and requiring special tools and hours of work.

In my case, the leak looks to be from a fitting or hose on my lower steering system, so I'll starting with the cheap and easy fix by adding power steering fluid to the reservoir. This should relieve the symptoms I'm currently experiencing, but it won't actually correct the problem; to do that, I'll have to pinpoint where the leak is originating from and replace or repair it. I'll detail the actual repair when I do it, but I'll explain the basics of leak identification now.

Identifying the Leak
The first step in identifying a leak is noticing that it exists. When you get in your car, take a quick look at the ground underneath it. If you see wet spots under your car, especially on multiple occasions, that's a strong indicator that something may be leaking.

Power steering fluid, like most of the fluids in your vehicle, is oil-based. Many of the systems in your car, including braking, steering, and transmission are hydraulic, and the oils in these systems hold up to heat and pressure well. They may even contain detergents or other additives to enhance the longevity and effectiveness of these systems.

The oily nature of these fluids makes them fairly identifiable, and the color of the fluid also can help identify the problem system. Touch the wet spot with your finger, then feel and look at it.

• If it's watery but not oily, green or orange, and maybe a bit sweet smelling, it's probably coolant. 
• If you see a red, oily fluid, that's likely to be automatic transmission fluid. 
• If it's amber or brown and oily, it could be motor oil, power steering fluid, or possibly brake or clutch fluid. 

Once you've narrowed down the possible suspects, check the relevant reservoirs.  The reservoir with a low fluid level will be the culprit, so fill it to the correct level with the proper fluid to alleviate the symptoms. (Your owner's manual will tell you where each reservoir or fluid check location is located.)

Locating the Leak
Locating the point of the leak takes a bit of work and attention. Thoroughly clean any area that you suspect the leak may be coming from; a bit of good detergent will break down the oils and help in cleaning.

Some systems (such as cooling) have UV reactive dyes you can purchase, so if this is available for the system causing you problems, adding it now will make detection much simpler. The dye can be bought separately if you already have a blacklight, or can be purchased as a kit with dye, light, and possibly tinted glasses to help see the dye.

You simply add the dye to the appropriate reservoir, run the engine for a while (I like to drive around for a day or two) and check with the blacklight. The dye will glow just like blood detection on a police show, showing you everywhere the fluid has landed and where it came from. Then it's a matter of doing whatever repairs are necessary.


Keep an eye on your fluid levels and on the ground; it can save you from some very expensive repairs.

Lokidude