MM Model U overheating

Cornettd · Oct 28, 2023

Recently came across a '49 model
U. Having issues with it
overheating. Replaced the
thermostat with no change.
Radiator is clean. Could I have
issues with the water pump not
circulating water sufficiently?
How big of a job is a water pump
replacement?

molinegb · Oct 29, 2023

You can't replace water pump. Has a brass impeller and two seals. Maybe impeller bad.

Ill John · Oct 29, 2023

I think what gb meant is you can replace the seals, and/or the impeller. it is held on by a castle nut with left hand threads

SWMolines · Oct 29, 2023

(quoted from post at 16:15:57 10/28/23) Recently came across a '49 model
U. Having issues with it
overheating. Replaced the
thermostat with no change.
Radiator is clean. Could I have
issues with the water pump not
circulating water sufficiently?
How big of a job is a water pump
replacement?

Did the thermostat have a bleed thru hole in it? You may want to pull the t-stat out and run the tractor without it and see if it circulates water. You can also pull the lower radiator hose and make certain that water is discharging out the bottom of the radiator. Sometimes the lower ends of the radiator tubes will clog from sitting if not run for long periods of time.

used red MN · Oct 29, 2023

SW said.. You can also pull the lower radiator hose and
make certain that water is discharging out the bottom
of the radiator. Down those lines a quick on the tractor
radiator flow check is as follows. Drain coolant
disconnect the lower radiator hose. Either you will
need a plug or an extra hand to close the bottom
radiator outlet. Now knowing you have a thermostat in
it you can be assured water you add to the radiator will
fill the radiator and be held by the thermostat from
going in the engine. After the top tank of the radiator is
full open the bottom outlet. It should flow out of the
radiator in nearly a full stream the size of the lower
outlet emptying the top radiator tank quickly. If the
flow is slow and the top tank level drops slowly the
radiator flow is probably not adequate. Which means
tube plugging as SW suggested. If Molines have short
straight hoses that set between two rigid tubes it can
be a difficult test to facilitate.

wilson ind · Oct 29, 2023

COMMERCIAL PUMP 713 864 5199

MM Model U overheating

Cornettd

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molinegb

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Ill John

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SWMolines

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used red MN

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wilson ind

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