expansion tank

Can anyone tell me where the best place is for the expansion tank take off is? thanks

 

[Ian Clark]

Hi Paul,

Your expansion tank wants to come off the upper rad hose and be higher than the hose itself. It's very important to keep the thermostat wet so make sure the header tank always has coolant in it before taking the road.

You can fab up a tee fitting into the upper hose or plumb into the waterpump housing on the intake manifold.

It's also a good idea to let the engine come up to temperature slowly and completeley befor standing on it. These cars can boil over so fast it'll make your head spin.

Cheers

 

[Phil]

Paul..
Good advice from Canuk 40.
Also my radiator has two small bleeders on the top corners to take out any air in the system. You will find these on many small Japanese cars as the radiator is lower than the topmost water outlet on the motor. I also had a small problem with cooling because of a pressure drop as the coolant traveled forward from the top of the engine to the radiator, this was solved by slightly restricting the outlet at the radiator, so that the water pump developed pressure pushing the coolant forward through the radiator. Sometimes when running in real hot weather the slight pressure drop thru the tubes was causing the coolant to boil, and this solved that. Rule of thumb is each pound of pressure adds 3 deg.F to the boiling point.
Good luck
Phil

 

[Chris Duncan]

"Can anyone tell me where the best place is for the expansion tank take off is? thanks"

It depends what your referring to. There are 2 tanks involved with cooling systems, one is an expansion tank, the other a recovery tank, they are also called overflow and catch tanks, but I've seen people call a recovery tank an expansion tank.

The expansion tank has a radiator cap, it's essentially so you can fill the system at the highest point. A recovery tank is so the system can be run in full condition all the time. It's connected to the radiator cap bleed off line, when the fluid expands from heat it over-pressures a valve in the cap and runs into the recovery tank. When the system cools it sucks the fluid back past the cap into the system. Before recovery tanks were used you couldn't fill the system completely, you had to leave some air to allow for expansion otherwise fluid would overflow.

An expansion tank runs at system pressure and a recovery tank is not pressurized.

The expansion tank connects with a AN8 line to the low pressure side of the system, usually in the tubing coming back to the water pump from the radiator. It also has a small AN3 line from the top of the engine to keep the system bled. A heater or bypass hose can also be connected.

The recovery tank connects to the AN3 or 4 line coming off the radiator cap, it also has a overflow line running to the ground.



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