Vital Fluids and How to Find Them

In any vehicle there are a variety of vital fluids that keep you going down the road safely and smoothly. In order to assess and correct any issues with these systems, you need to know what you're looking for under the hood.

I talked before about finding, diagnosing and correcting a leak in my truck.The images I'll be using are from the engine compartments of two of my vehicles; they're not the be-all and end-all of under-hood layouts, but they give a good example. For your specific vehicle, look in your owner's manual, it should provide a complete layout of all of your vital fluid reservoirs and check points.

This is the engine compartment of my Miata. It is a manual transmission car without power steering, so there is no automatic transmission fluid (ATF) or power steering fluid to check. However, the blue circle is the clutch fluid reservoir. This reservoir, as well as the brake fluid reservoir next to it (circled in red) can simply be checked by noting the fluid level against marks in the exterior wall of the reservoir itself. Neither commonly gets low, unless a leak or very severe wear in the system develops.

The reservoir circled in green is the coolant reservoir, and the volume of fluid in this reservoir can change depending on your engine temperature. Your coolant expands as your engine heats up, and will lead to more fluid in this tank. It will have markings on the side for "Full Hot" and "Full Cold." DO NOT OPEN THIS BOTTLE WHILE YOUR ENGINE IS HOT! Severe burning is likely to result. When your engine has cooled, you can open this reservoir to add more coolant if needed, but do not fill above the "Full Cold" marking, thus leaving room for expansion to occur.

The areas circled in yellow are the oil level dipstick and the oil fill cap; the cap is the larger black piece towards the bottom of the picture. Your owner's manual will have instructions on how to read your dipstick, as some of them have several indicator areas on them.

This is the driver's side of the engine bay on my truck. The engine is big enough that it takes two pictures to show things properly. This truck is equipped with power steering and an automatic transmission, so there is no clutch fluid reservoir, but there are ATF and power steering fluids to check.

The purple circle is both the dipstick and filling port for power steering fluid. It's a very small reservoir, but a very important one to safely drive a vehicle of this size. The red circle is again the brake fluid reservoir, and the only difference from the Miata is size.

This is the passenger side of the bay. The yellow circles are again the dipstick and filling port for motor oil. The green is still coolant, and the same warning applies on the big diesel as the baby gas engine. Opening this cap on a hot engine is almost guaranteed to result in very nasty burns.

The area circled in orange has my automatic transmission fluid dipstick. On this engine, it's hidden behind my turbocharger piping, but it's back there and very well marked. On some vehicles, it is on the driver's side of the engine, but it will almost always be towards the rear of the engine compartment and well marked. The procedure for checking this fluid is fairly involved and a bit vehicle specific, so consult your owner's manual for the specific instructions to perform this check.

Keep your engine's fluids topped up and in top shape, and she'll purr like a kitten for years.

Lokidude