STATUS UPDATE APRIL 26th ... the saga continues ...
OK - first off, I screwed-up on my initial fan replacement part order... the correct/original fan size for my PT1430 is an 11" fan - NOT the previously assumed 12". So please ignore and forgive my previous posts with the SPAL part numbers for 12" fan options. Luckily I was able to return the first 12" SPAL fan I ordered, and have since ordered, received, and installed an upgraded and proper fit 11" SPAL fan. The original fan on my ~2005 year PT1430 was SPAL p/n: 30100364 (11", Low profile, straight blade, pull) - specs say this is either 755CFM or 808CFM depending on who's description you are looking at. The "upgraded" fan options were: SPAL p/n: 30100411 (11", Low profile, curved blade, pull) - specs say this is a 844 CFM unit; or the one I went with is the SPAL p/n: 30101500 (11", MEDIUM profile, straight blade, pull) - specs say this is a 962 or 970 CFM fan. This new fan was installed and tested fine when jumpering/by-passing the thermo switch mounted on the radiator cooler.
Then I waited for 4 days of rain to finish, before I could get out (today) and start to move and spread a 10 ton pile of #57 gravel (luckily not needing to move up/down a steep slope area) ... and here are the results from today's work and testing ....
(1) After about 40 minutes of run-time in ~76°F outside temps, the engine temp was showing at just over 160 on the gauge, and checking the hydraulic oil temp directly at the tank, the oil temp was at about 140°F. Using the laser spot thermometer I was finding it would read basically the same (within a few degrees) of the direct oil temp just by pointing at the main pump and hose fittings to allow for a quicker and easier temp measurement instead of opening the tank cap to measure the oil directly.
(2) At this point in the oil temp warm-up, the [new] cooling fan had not yet come on at all. Also, I was starting to feel like I was getting more wheel spin starting when trying to get a bucket load of gravel from the pile, instead of getting a good push into the gravel pile for a full bucket load, would only get about 3/4 of a bucket full then the front wheels would start spinning.
(3) I checked the temp of the cooler radiator with the laser spot thermometer -- it was only showing about 90°F and was even temps on both sides of the radiator and anywhere on the radiator itself. Rechecked that the fan would spin-up when by-passing the thermo switch--but at only 90°F, the thermo switch was clearly not kicking on.
(4) Kept moving/spreading gravel, for another 30 to 40 minutes...rechecked oil temps again using the spot thermometer on the pumps/connections and the radiator ... Now showing oil(pump) temps at 165°F-170°F - but the radiator is only at 100°F and there is NOT any difference in temps from one side of the radiator/hoses to the other and the fan is still not turning on. So I am really thinking I am NOT getting any oil circulation through the radiator. The hoses appear to run from each side of the radiator back to the main pump area just under the fuel tank and appear to be connected -- but it sure does not appear that 165°F oil is flowing through these hoses--they are not that hot to the touch.
So, again, I have run well past my very limited knowledge of Power Trac hydraulic operations here .... is there some thermo valve or diverter that could be not opening to properly route oil to the cooler radiator? It is possible/likely something could create a "clog" in those large hoses feeding to/from the radiator? Would the 170°F hydraulic oil temp be so high as to explain the greater tendency to have these wheel spins instead of distributing the power where it needs to be going? What am I damaging with this kind of oil temp? Maybe time for another call to Terry tomorrow to plead for guidance on what to check out next...