Reading the puddle in your driveway
A spot under the car is the most common reason people ask us about fluids, and the colour gives a good first guess. Put a sheet of white cardboard under the engine overnight and you will see it clearly.
- Green, orange, pink or blue, thin and sweet smelling, is coolant.
- Red or reddish brown and slippery is automatic transmission fluid, or power steering fluid on cars that use the same type.
- Light brown to black and oily is engine oil.
- Thick and dark with a strong sulphur smell is gear oil from a differential or transfer case.
- Thin, clear to yellowish, and found near a wheel, may be brake fluid. A brake fluid leak can take away your brakes, so do not drive the car until it is checked.
- Plain water under the front passenger side on a warm day is the air conditioning draining, and it is normal.
Washer fluid is usually blue and smells of alcohol. It drips from a cracked reservoir or hose and is harmless, but a leaking reservoir in January is annoying, so it is worth fixing.
Coolant
Coolant carries heat from the engine to the radiator and keeps the water in it from freezing. It also carries corrosion inhibitors, and those wear out with time even when the coolant looks clean. Old coolant starts eating at water pumps, radiators and heater cores from the inside.
In Ottawa the freeze point matters. A 50/50 mix protects to around minus 37, but coolant topped up with plain water for a few years can freeze in a cold snap and crack something expensive. We test the strength, not just the level. Leaks, overheating and heater problems are covered on our cooling system page.
Brake fluid
Brake fluid is usually changed by time rather than kilometres, because it slowly pulls water out of the air through the hoses and seals. It is also the fluid people most often forget, since the brakes feel normal right up until they do not. We test it rather than going by how long it has been or how it looks. If your brakes need pads or rotors anyway, it can be done on the same visit as the brake repair.
Transmission fluid
Automatic transmission fluid cools the transmission, lubricates it and is the hydraulic pressure that makes it shift. When it breaks down from heat, shifts get harsh or slow. Plenty of newer automatics have no dipstick at all. Their fluid is checked from a fill plug underneath, with the engine running and the fluid at a specified temperature.
A drain and fill only replaces part of the fluid, since a good amount stays in the torque converter and the cooler lines. That is normal, and for a transmission that has been neglected for a long time a gentler approach is sometimes wiser than a full exchange. Continuously variable transmissions and dual clutch gearboxes each need their own exact fluid, and the wrong one can damage them. If shifting is already rough, a fluid change will not cure it, and the transmission repair page explains what we check instead.
Differentials and transfer cases
Rear wheel drive cars, pickups and almost every all wheel drive vehicle in Ottawa have gear oil in a differential, and many have a transfer case as well. These are easy to forget because they rarely leak much and have no warning light. Old gear oil leads to a whine on the highway that gets louder with time. On some all wheel drive systems, worn fluid in the rear coupling causes a shudder or groan on tight turns in parking lots.
Power steering fluid
Hydraulic power steering uses a pump, a reservoir and hoses. The fluid darkens and wears out, and a pump that groans on cold mornings often has low or tired fluid. Many newer cars have electric power steering with no fluid at all, so we check which kind you have before suggesting anything.
What fluid work costs
Fluid services are priced by vehicle, since capacities and fluid types vary so much. A fluid check, to see what is due and what is not, is billed as inspection time at $120 an hour before tax. If you are coming in for a full synthetic oil change, from $99, mention it in the booking and we will look at the other fluids while the car is up.
Booking
We are at 1345 Marchand Street in Cyrville, Ottawa, ON, near the St. Laurent Shopping Centre, and we are open Saturdays as well as weekdays. Book online any time and add your service records to the notes, or a photo of the maintenance page from your manual. That tells us what is due without guessing.
Questions
What colour is the fluid leaking from my car?
Green, orange, pink or blue fluid with a sweet smell is usually coolant. Red or reddish brown and oily is usually automatic transmission or power steering fluid, brown to black is engine oil, and a thin clear or yellowish fluid near a wheel can be brake fluid. Clear water dripping under the front passenger side in summer is normal condensation from the air conditioning.
How often should transmission fluid be changed?
It depends on the transmission and how the car is driven, and the owner's manual gives the interval for normal and severe use. Some makers call the fluid lifetime, which in practice usually means the length of the warranty. Stop and go traffic, pulling a trailer and short winter trips all count as severe use, which shortens the interval.
Is a fluid flush necessary or an upsell?
It is necessary when the manufacturer's schedule calls for it or a test shows the fluid has broken down, and an upsell when neither is true. At 2 and 1/2 Mechanics we check the schedule for your car and the condition of the fluid before recommending anything, and no fluid gets changed without your approval.
What antifreeze protection do I need in Ottawa?
A proper 50/50 mix of coolant and water protects to around minus 37 degrees, which covers an Ottawa winter. Coolant that has been topped up with plain water for years can lose that protection. Testing the coolant itself, not just the level, shows the real freeze point.
Does my all wheel drive car have extra fluids?
Usually yes. Most all wheel drive cars and SUVs have a rear differential and a transfer case or power transfer unit, each with its own gear oil, and some use a special fluid for the clutch pack that sends power to the rear. These are easy to forget and often overdue.
