Car Parts Discount
Coolant By-Pass Hose

Aftermarket & OEM Coolant By-Pass Hose

The by-pass hose is a small but important part of your cars cooling system. Your car's engine operates most efficiently when it has warmed up. When you start your car cold this hose offers enough coolant to prevent the car from overheating. Once the engine is warm and operation properly the regular cooling system takes over. The part it is by-passing in order to do it is the thermostat and that is how the part got its name. This part holds together pretty well but may break or leak. If your car has trouble warming up or overheating it may be because of the by-pass hose. It works to equalize the pressure around the water pump and ensures that flow is not interrupted. Allowing a cracked or rusting by-bass hose may cause overheating or difficulty starting especially in cold weather. Like any other rubber piece, it will gradually wear out and will only get worse over time. Tape may temporarily solve the problem but it is better to just replace it. Not doing so may affect other parts of the car like the water pump. We also have other cooling components like the thermostat, thermostat housing, radiator, and various other cooling hoses.

The by-pass hose is generally a very small and short hose. They are made of black rubber. They often have sort of an elbow shape but can be elongated and irregular to move around the engine and avoid hitting other components. Not all vehicles have a by-pass hose but may have a passage instead that serves the same function. Still others may use a metal pipe that may rust. Some older cars are air-cooled and do not have a hose, but since virtually all vehicles are water-cooled they use this hose; helping the engine to warm up from a cold start.

The by-pass hose is a small part and simply to replace. We have some general instructions to help understand what it takes to change out this part. If you do the work yourself be sure to have the correct parts and a good shop manual. If not, any auto mechanic should be able to replace the part on your car.
  • Find the location of the hose.
  • You may need to jack the car to see underneath or simply open the hood.
  • Drain the radiator to just below the coolant hose.
  • Remove the hose after loosening the clamps.
  • Install the new by-pass hose and tighten the clamps.
  • Inspect all other parts of the cooling system. Fill the vehicle back up with coolant.
  • Start the car and check for leaks to make sure it is running at the right temperature.

We offer a selection of great by-pass hose brands like Gates, URO, CRP and Dayco as well as the genuine OEM part for some vehicles. Use our great customer service and low prices to find the parts that you need shipped to you fast. Be sure to check out all the other cooling parts that we have for your car or truck like the radiators, coolant hoses, thermostats, water pumps and different kinds of coolant. Get ready to walk out to your confident that it will start and take the longest trip knowing that your cooling system is working properly when you receive a new coolant by-pass hose.