Fluid Leak Diagnosis and Repair In Missoula.

Fluid leak diagnosis means figuring out which fluid is leaking and exactly where it's coming from. Your vehicle runs on several fluids: engine oil, coolant, transmission fluid, brake fluid, power steering fluid on many vehicles and gear oil in the differentials. Each one is sealed in its own system by gaskets, seals, hoses and lines. When one of those wears out, cracks or loosens, fluid gets out and the system it protects starts running low.

The color and feel of a spot give you a first clue. Engine oil is usually brown to black. Coolant is often green, orange or pink and smells sweet. Automatic transmission fluid is usually red or reddish brown. Brake fluid is clear to amber and feels slick. Gear oil from a differential is thick with a strong, sulfur-like smell. Clear water dripping near the front of the vehicle after you've run the A/C is usually just condensation, and that's normal.

Leaks rarely fix themselves, and a small one can lead to a big repair. Low oil can damage an engine. Low coolant can lead to overheating. A transmission that's low on fluid can slip and wear itself out. A brake fluid leak affects your ability to stop and should be checked before you keep driving. Oil dripping onto a hot exhaust can also cause smoke and a burning smell.

Finding the source takes more than looking at where it drips. Fluid runs along the engine and frame, and air moving under the vehicle pushes it back, so the drip point is often a ways from the leak. We put the vehicle on the lift, identify the fluid, and follow the trail back to where it starts. When a leak is hard to pin down, we may clean the area and check it again after some driving to see where fresh fluid shows up first.

The source decides the repair. An oil leak might be a valve cover gasket, an oil pan gasket or a seal. A coolant leak might be a hose, the radiator or the water pump. Transmission and differential leaks often come from a pan or cover gasket, a cooler line, or an axle or pinion seal. Those jobs vary a lot in size, which is why we find the source before quoting a repair.

Then we tell you what we found, how serious it is, what needs attention now and what can wait, and what each option costs before work starts. Some slow seeps are fine to keep an eye on for a while, and we'll tell you when that's the case. If you've been quoted a big leak repair somewhere else, we'll give you a free second opinion.

One thing you can do before you come in: slide a piece of cardboard under the vehicle overnight and note where the drips land and what color they are. Snap a photo or bring the cardboard with you. It gives us a head start.