question for the john deere guys

[cutter88]

was coming out with my last hitch tonight with my 1988 640d and all of the sudden the heat gauge spiked and she started puking anti freeze out the over flow line by the rad cap??? ran the machine all summer in hot tempetures and pullen heavy and she never heated up once so what could make it spike like that on a cool day when it want even working hard????
any tips would be appreciated

[PaYoungBuck]

Maybe the thermostat or water pump failed? Something blocking a line? Feel the hoses and see if and where they are hard for pressure/ temp

[chevytaHOE5674]

Water pump working? Fan belt present and tight? Thermostat working? Hose collapsed? Any one of this things can cause it to overheat.

[TheDirt]

do you have a quick connect on a coolant line so you can hook the system up to a warm pickup or whatever on cold mornings? I had just the tiniest amount of sediment clog one of my lines at the disconnect and spent days watching my temp go crazy and blow the cap, then drop right down to cold, finally figured it out after being certain I'd blown a hole in the new cummins.

[PaYoungBuck]

Dirty/ clogged radiator fins

[ga jones]

My buddies timberjack did that last winter. The radiator hoses were breaking down internally. Pieces of rubber from the hose blocked the thermostat.

[Nemologger]

Sure acts like the thermostat to me. My 548 did the same thing a couple years ago and a pair of thermostats fixed it...Good luck!

[treeslayer2003]

you still got yer clark? I have 2 clarks 1 international and a 540b deere. had to rebuild the deere last year because it ate a pinhole in one liner. mine leaked into the base but I heard of cummins pressurizing the radiator from liner pinholes. just a thought, good luck.

[justincase]

I Have a 440d that did same thing. New thermostats and make sure they have a small hole in rim or drill a hole. I took mine apart 4 times before I realized it was air locked just below thermostat and needed just a little flow of coolant to open. I lost a lot of hair on that one.

[Icehouse]

I run my skidder during the summer with my fan in the pusher setting, sure helps keeping the radiator not so dirty from all the dust. But your problem sounds thermostat to me.