Oil Changes and Fluid Services: What Your Vehicle Needs and When

Crossroad Garage service team · Ellensburg, WA

Fluids are the lifeblood of your vehicle. Engine oil, coolant, transmission fluid, brake fluid, power steering fluid and gear oil each have a job, and each one breaks down over time. Keeping them in good condition is one of the simplest ways to avoid big repair bills later.

Engine oil

Oil lubricates, cools and cleans the inside of the engine. As it ages, it loses its ability to protect, and it collects soot, fuel and moisture. Diesel engines in particular produce soot that ends up in the oil.

Your owner's manual lists the correct oil type and service interval. Many manuals also have a severe service schedule. Towing, short trips in cold weather, dusty gravel roads and lots of idling all count as severe use, and a lot of driving around the Kittitas Valley fits that description. If your vehicle has an oil life monitor, follow it, but still check the oil level between services.

Signs your oil needs attention

• An oil pressure or oil change warning light.
• Oil level dropping between changes, or oil spots under the vehicle.
• Oil that looks milky, which can point to coolant getting into the oil and needs prompt attention.
• New engine noises, such as ticking or knocking.

Coolant

Coolant keeps the engine from overheating in summer and from freezing in winter, and it protects the cooling system from corrosion. Ellensburg sees both hot summer days and deep winter cold, so coolant has to do both jobs. Over time the corrosion protection wears out. Watch for a rising temperature gauge, a sweet smell, puddles under the front of the vehicle or a heater that blows cold. We can test the coolant's condition and freeze protection and inspect hoses, the radiator and the water pump for leaks.

Transmission fluid

Transmission fluid lubricates and cools the transmission and, in automatics, is what makes it shift. Heat is its enemy. Towing, hauling, mountain grades and bigger tires all raise transmission temperatures. Harsh or delayed shifts, slipping or a burnt smell can be signs of fluid problems or something more. Not every transmission has a dipstick, and some need special procedures to check the level correctly, so it is worth having a shop do it. For transmission problems beyond a fluid service, see diesel transmission builds and repair.

Brake fluid

Brake fluid absorbs moisture from the air over time. That lowers its boiling point and can lead to a soft pedal on long downhill runs, plus internal corrosion. We can check its condition and recommend a flush when needed.

Differential, transfer case and power steering fluid

Trucks and 4x4s have gear oil in the front and rear differentials and fluid in the transfer case. These are easy to forget, but water crossings, heavy loads and towing can make them wear out sooner. Power steering systems also use fluid that can leak or break down. We check all of these during a fluid inspection.

What we check during a fluid service

• Correct fluid types and levels for your specific vehicle.
• Condition of each fluid, including color, smell and contamination.
• Leaks at gaskets, seals, hoses and lines.
• Filters that go with the service, such as the oil filter and air filter.
• Belts and hoses we can see while we are under the hood.

Diesel trucks

Diesels often hold more oil, may need specific oil ratings and have fuel filters and water separators that need regular service. If you tow or work your truck hard, ask us about the severe service schedule for your engine. For bigger engine work, see diesel engine builds and repair.

When to come in

Stop driving and call us if the oil pressure light comes on or the engine starts to overheat. Schedule a visit if you are due for an oil change, see a leak, or are not sure when the other fluids were last serviced. Fall is a good time to check coolant and battery condition before winter.

See all of our auto and diesel services, diesel engine builds and repair, diesel transmission builds and repair, or browse more tech tips on the Crossroad Garage blog.