TW 35 Spewin' coolant update

Have run 2 tests for cracked head/blown gasket - ran 30 seconds & cracked cap - no pressure. Started up cold w/cap off & checked for bubbles - didn't see any. Bought infrared thermometer to check upper & lower hose temp. Here might be a problem - took side shields off to get to hoses easier & ran for a good while. Didn't want to puke any then, but finally spit just a little coolant out. Thinking it may have been a mistake to leave off the shields since it didn't want to act up then, but anyway, I checked both hoses and found 157 deg. on lower and 173 on the upper. When I drove it home & checked it when I parked it, I got 146 lower temp & 165 upper. Is this enough difference to indicate a flow issue? Or, since the side shields were off and presumably it got more air, could it be the fan clutch? Thanks for all the input thus far.

Side shields open or closed won't make much difference. I also don't trust infrared guns on rubber hoses.

Do what I said earlier: get it up to operating temp, and then stick the overflow hose in a jar with water and look for bubbles while you're working it hard. A few bubbles here and there is OK, but a steady stream is not good, especially if the intensity of the bubbles is proportional to the load.

I'll take a stab at it. I'm bushhogging on some pretty good sidehills right now. Looks like that would be a good test when hooked up to a dyno.

A 20 to 25 degrees temperature drop from top to bottom is about right on a cooling system provided that's what you have when working the tractor. Flow issues can be found with non contact thermometers. Look for cool spots on the core as soon as it warms up, don't wait for an hour when the radiator temp. will even out. We use a dye kit from Snap-on to check for the presence of exhaust in the cooling system.

Thanks. That"s what I used. Bought an infrared thermometer (non-contact) yesterday and checked temp w/that. I"ll check on the dye kit today. Thanks for the tip.

Warmed tractor up & stuck overflow hose in jar. No bubbles. Ran for 1 hr. No spitting or spewing out tube. Ran another hour. Spit a little here & there under a load, but quit fairly quickly. One more hour. Began to spit more frequently & spewed a steady stream, but never "geysered" like it had before. Checked gooseneck temp w/infrared - 250 +/-. Lower hose (hard steel hose) - 220 +/-. Came back home. Quit spewing after I went to a higher gear on the road (I was just a couple hundred yards from shed). When I got home, only drops of water coming out of overflow tube, but could still see steam. Condensor & radiator covered w/pollen & dust. Blew them clean w/air. Could still see light steam out of overflow & a few water drops. Temps at gooseneck & lower hose had dropped. 190 top, 130 bottom. Also, top hose looked ballooned above gooseneck, normal size coming off top of radiator, if that means anything. Going back outside now to check on it.

Weird thought (cannot recall what your other thread stated) but do you think the radiator is "plugged"? Perhaps take to a shop in town and see if they can boil it out and test...

Could be I suppose. That thought crossed my mind. That may be the next thing I test.

Is the fan pulley worn out? We had to replace the one on our TW30 as the belt would bottom out in the groove and the belt would slip even though it was tight. If the belt is below the level of the cast pulley sides chances are its bad. We replaced the bearing at the same time.

Sometimes... I think you have to stop overthinking and get back to the basics. My 7710 was on cook all of the spring season last year. I blew the rad out. I tightened the belts. I drained and flushed the block/rad with a phosphoric acid solution... I was down to the point I thought either the broken fan shroud was causing the problem or the water pump impeller was worn out. When I finally pulled the nose off to do some work on the air cleaner... and pulled the coolers out... I realised that the rad was blocked SOLID. Not with chaff or pollen or dust as it usually is... with hard caked soot that was getting drawn in there from an exhaust leak. It literally took more than half a day to blow and wash that mess out. Now it runs as cool as it ever did and I still haven't installed the new shroud...

It seems to me that your problem may be related. SO look real close at it. Get it good and clean. Then drain her out and get that crap out that you dumped in last week and run a phosphoric acid flush through her... and triple rinse to get all of that out or wash until the suds/bubbles stop. You'll be amazed at what garbage a commercial fast flush product will remove that vinegar will not remove. Then refill and see how things go.
I'm a little concerned about the bubbles you're getting occasionally... but given the temperature it was at that may not be surprising. Most times I've seen head gaskets fail on Ford engines (and I've had a few) they continue puking until they puke enough/all of their coolant, THEN they run hot. I've yet to see one run hot while it's actively puking coolant. If you open the cap it will blow the cap off in your hand and often form a geyser of black froth. The coolant will be absolutely black, oily and foaming...
I think you just have a hot engine from lack of cooling capacity.

Rod

Sounds like the heat can't be moved fast enough under load. Loose belt? Did you visually check for flow in the radiator with the cap off when the thermostat was open? The water pump should provide movement similar to a garden hose turned on pretty good at high RPM's.