Water pump on my caravan is only pumping air but shows no visible water leaks, help ?

Question

Water pump on my caravan is only pumping air but shows no visible water leaks, help ?

Answer 1

could be the non return valve inside it?

Answer 2

Certainly and odd question but I had an experience that may relate.

I had a Trans Am and it had an air bleed valve near the thermostat on the cooling system.  You had to open the valve when filling the system with fluid and you had to crack it open and bleed the air out when it was running / heating up.  If you didn't, the pump would cavitate and stop pumping water.  The system would not tolerate any leakage because it would draw air in when cooling and it would cause cavitation.

This system was required because the top of the radiator was lower than the top of the engine and air would get trapped in the engine.

Edit.

Thinking back, I believe my neighbor used to have a caravan with an air bleed valve.  I seem to remember explaining it to him. If the top of the radiator is below the thermostat, it must have one.

Answer 3

Is the radd full?

Answer 4

Have you got water in your tank?

:D

Answer 5

You won't have a water leak as it seems the problem is on the suction side, so carefully check pipes, joints etc. between the pump and water supply....

Answer 6

Thermostat stuck closed.

Answer 7

water pumps now days can go bad without leaking a drop of coolant they just get worn out,if its not pumping any coolant and you drive the vehicle you will get it hot and possibly blow a head gasket on it,or ruin a good engine,have it checked,good luck.