Kenworth T660 Coolant Reservoirs

Frequently Asked Questions About Kenworth T660 Coolant Reservoirs

What does a coolant reservoir do on my Kenworth T660?

The coolant reservoir, also called an overflow or surge tank, holds extra coolant for your cooling system and provides a space for coolant to expand and contract as engine temperature changes. It also allows air to be purged from the system and gives you a quick visual way to check coolant level without opening the radiator cap.

How do I know if my coolant reservoir needs to be replaced?

Common signs include visible cracks or stress lines in the plastic, coolant leaking from the tank itself, a reservoir that will not hold pressure or level properly, a discolored or brittle cap, or repeated low coolant warnings even after topping off. Sun exposure and heat cycling over time can make the plastic brittle, so cracking is one of the most frequent failure points.

Will a replacement reservoir fit my T660 without modification?

Reservoirs are designed to match the mounting points, hose connections, and cap style used on the T660, but exact fitment can vary depending on the model year and engine configuration. It is a good idea to compare your existing reservoir's shape, mounting bracket, and hose fittings to the listing photos and specs, or check with our team before ordering if you are unsure.

Are these reservoirs made from the same material as the factory original?

Most coolant reservoirs, whether OEM or aftermarket replacement, are made from a translucent or semi-translucent high-temperature plastic designed to handle constant exposure to hot coolant and engine bay conditions. This material also lets you see the coolant level through the tank wall, which is why replacements are typically molded from a similar type of plastic rather than metal.

Can I install a new coolant reservoir myself, or does it need a shop?

Many drivers and fleet techs replace a coolant reservoir themselves since it generally involves draining or lowering the coolant level, disconnecting hoses, unbolting the old tank, and installing the new one in its place. If you are not comfortable working around a pressurized cooling system or your truck has a more involved hose routing, having a qualified technician handle it is a safer option.