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Understanding Tractor Engine Coolant

We want to teach you all about engine coolant to help your tractor run cooler and last longer.

If you do not feel that you understand these tips, steps, and strategies, or can perform them safely, consult your tractor dealer or local mechanic.

NOTE: There are a few important things to know before servicing your coolant.

Scald Hazard

Here are some ways to help you keep from getting scalded when servicing your coolant:

  • Never remove the radiator cap if the engine is hot. Steam and hot engine coolant will spurt out and seriously burn you.

  • Allow the engine to cool down before you attempt to remove the radiator cap.

  • Tighten the radiator cap securely after you check the radiator. Steam can spurt out during engine operation if the cap is loose.

  • Always check the level of the engine coolant by observing the reserve tank.

  • Failure to comply will result in death or serious injury.

Burn Hazard

Here are some ways to help you keep from getting burned when servicing your coolant:

  • Wait until the engine cools before you drain the engine coolant. Hot engine coolant may splash and burn you.

  • Failure to comply could result in death or serious injury.

Coolant Hazard

Here are some coolant hazards to keep in mind when servicing your coolant:

  • Wear eye protection and rubber gloves when you handle a long life or extended life engine coolant.

  • If contact with the eyes or skin should occur, flush eyes, and wash immediately with clean water.

  • Failure to comply may result in minor or moderate injury.

Coolant Warnings

Here are some basic tips to prevent hazards:

  • Only use the tractor engine coolant specified. Other engine coolants may affect warranty coverage, cause an internal buildup of rust and scale, and/or shorten engine life.

  • Prevent dirt and debris from contaminating the engine coolant. Carefully clean the radiator cap and the surrounding area before you remove the cap.

  • Never mix different types of engine coolants. This may adversely affect the properties of the engine coolant.

Engine Coolant Specifications

Use a Long Life Coolant (LLC) or an Extended Life Coolant (ELG) that meets or exceeds the following guidelines and specifications:

Additional technical coolant specifications:

  • ASTM D6210, D4985 (US)

  • JIS K-2234 (Japan)

  • SAE J814C, J1941, J1034 or J2036 (International)

Alternative engine coolant

If an Extended or Long Life Coolant is not available, you may use an ethylene glycolor propylene glycol based conventional coolant (green).


  • Always use a mix of coolant and water. Never use water only.

  • Mix coolant and water per the mixing instructions on the coolant container.

  • Water quality is important to coolant performance. YANMAR recommends that soft, distilled, or demineralized water be used to mix with coolants.

  • Never mix extended or long life coolants and conventional (green) coolants.

  • Never mix different types and/or colors of extended life coolants.

  • Replace the coolant every 1,000 engine hours or once a year.

Filling Radiator with Engine Coolant

Fill the radiator and reserve tank as follows. This procedure is for filling the radiator for the first time or refilling it after it is flushed. Note that a typical radiator is illustrated.

1. Check to be sure the radiator drain plug is installed and tightened or the drain cock (Figure 4-7, (1)) is closed. Also make sure the coolant drain plug (Figure 4-8, (1)) in the cylinder block is closed.

2. Remove the radiator cap (Figure 4-7, (2)) by turning it counterclockwise about 1/3 of a turn.

3. Pour the engine coolant slowly into the radiator until it is even with the lip of the engine coolant filler port. Make sure that air bubbles do not develop as you fill the radiator.

4. Reinstall the radiator cap (Figure 4-7, (2)). Align the tabs on the back of the radiator cap with the notches on the engine coolant filler port. Press down and turn the cap clockwise about 1/3 of a turn.

5. Remove the cap of the reserve tank (Figure 4-7, (3)), and fill it to the LOW (COLD) mark (Figure 4-7, (4)) with engine coolant. Reinstall the cap.

6. Check the hose (Figure 4-7, (5)) that connects the reserve tank (Figure 4-7, (3)) to the radiator. Be sure it is securely connected and there are no cracks or damage. If the hose is damaged, engine coolant will leak out instead of going into the reserve tank.

7. Run the tractor engine until it is at operating temperature. Check the level of engine coolant in the reserve tank. When the engine is running and the engine coolant is at normal temperature, the coolant level in the tank should be at or near the FULL (HOT) mark (Figure 4-7, (6)). If the engine coolant is not at the FULL (HOT) mark (Figure 4-7, (6)), add additional engine coolant to the reserve tank to bring the level to the FULL (HOT) mark.

Engine Coolant Capacity (Typical)

Note: Capacities listed are for engine only without a radiator. Refer to the operation manual provided by the driven machine manufacturer for actual engine coolant capacity on your machine.

The following are the engine coolant capacities for various YANMAR TNM and TNV engines.

If you need any further help, or have any questions about tractor engine coolant, tractors, or anything else, please contact your dealer, local mechanic, or call us at 602-734-9944. Please ask about our current new and used tractor supply.

Team Tractor and Equipment - #1 Tractor Dealer in Arizona. We sell and service most major brands of tractors including Yanmar, Kubota, John Deere, TYM, Mahindra, Kioti, Case, New Holland, Massey Ferguson, Ford, Deutz, Case IH, Farmall, International Harvester, Branson Tractors, LS, Shibura, Claas Tractor, McCormick Tractors, Valtra, Solis, YTO, Montana, and Nortrac.

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