Radiator Cap Pressure Rating

[JDF]

Does anyone know the correct pressure rating for a Mutsubishi D2050 radiator cap. My cap is not the original and it overfolws when worked hard. I suspect it may be the wrong pressure rating but I don't want to blow the cooling system either.

 

[PILOON]

Hi,
If the engine is the K3A or K3C (3 cylinder) the cap should be rated at 12.8 PSI and begins to open at 180 deg, fully open at 203.

Are the rad fins clean?
Also there is no expansion tank so it would be natural to have some overflow when hot.
Also blow away any dust and crap accumulation from your rad fins with compressed air from the engine side forewards ie opposite from fan action.

As a precaution I recently flushed my rad and replaced my coolant

 

[JDF]

Thanks for the info. It's a 4 cyl engine. Radiator is clean on the outside - don't know what it looks like on the inside. If I still have the problem with the right cap I guess I'll have to go further

 

[PILOON]

I am guessing that your tractor is 'vintage' so to speak.
Perhaps the easiest would be to drain and clean it with a commercial cleaning liquid solution sold at auto parts.
Generally that is an acid solution (or caustic) that will loosen all the scale and crud accumulation.
Instructions tend to read that you run the engine hot and then drain and flush before refilling with new antifreeze.

Many owners manuals, in fact, will reccomend flushing and installing new coolant at a predeterermined time. (often 5 years, I believe).
Actually I did just that recently on both my tractor and Jimmy, and installed all new antifreeze!