Yanmar 1500 Water pump solution

[VT_Hokie]

I was getting tired of watching my temp gauge crawl into the overheat zone while bushhogging so I came up the following fix for my pumpless 1500D. Using an auxiliary heater pump out of a high end Mercedes, I spliced it into the lower radiator hose on the tractor. It is tight with the connectors used, but I do have enough clearance from the fan belt. Surprisingly it has worked very well. Temp will range from 155 to 170 at constant 2,000 rpm in 90 degree weather while cutting. Ran it yesterday for 4 hours straight with no problems. Right now the pump is controlled manually through a simple switch. I just let the tractor get up to temp and turn it on. On the deluxe model I will have to incorp a thermal switch...have to remember to turn it off right now when I am done.

Here is the parts list:

Original Yanmar lower hose

1 1/8 to 1 in hose bib - (2X)

1 in elbows - 2X

1 to 1/2 in reducers - 2X

1/2 hose bibs - 2x

1/2 in hose ~ 3 feet

Aux heater pump. Got mine off ebay for $60 pretested.

14 gauge wire, connectors and a switch that can handle a couple of amps.

Comments: The pump has 18mm bibs, a little big for 1/2in hose but too small for 3/4 in. I shaved a little off the end of 1 1/8 hose bibs to get clearance from the fan belt. No leaks, no major electrical drain, don't know exactly how many amps are being pulled, just know that it works!!!

VT

 

[clemsonfor]

Why not have bought the waterpum conversion kit from Hoye. Proably more but less of a "rigged" look. but great job if it works long term.

 

[reb]

Clemsonfor, where can I find information on that conversion? I looked through Hoye's website in the YM1500 area and did not see it.

VT_Hokie, that is interesting. I will have to consider doing that.

This brings up a question--what is a satisfactory operating temperature? Some guys here say their tractors don't get above 190 under load. Mine will get up to nearly 230 under load on hot days, but since the factory switch for the warning light does not turn on until 238 (IIRC), I don't worry about it. If I didn't have the gauge I wouldn't know the difference. Another consideration is a comment I heard from a mechanic. He said an engine should run at least 212 to boil off condensation to avoid sludge in the engine. Any thoughts?

 

[clemsonfor]

i dont know i have just heard about 1500 water pump conversions and assumed they bought it from Hoye? i might do a search here to see what i find.

 

[clemsonfor]

OK Here it is i just searched and came up with an old post. Seem that there is a kit for a 1700 but NOT for the 1500. I mis spoke. Here is the link where Aaron from Hoye explains that one is not availible.

http://www.tractorbynet.com/forums/yanmar/139451-cooling-system.html

Those without water pumps that use the thermosyphon system make sure that your only using 25% radiator fluid to maximise the effeciency of the system.

 

[normde2001]

Clemsonfor, where can I find information on that conversion? I looked through Hoye's website in the YM1500 area and did not see it.

VT_Hokie, that is interesting. I will have to consider doing that.

This brings up a question--what is a satisfactory operating temperature? Some guys here say their tractors don't get above 190 under load. Mine will get up to nearly 230 under load on hot days, but since the factory switch for the warning light does not turn on until 238 (IIRC), I don't worry about it. If I didn't have the gauge I wouldn't know the difference. Another consideration is a comment I heard from a mechanic. He said an engine should run at least 212 to boil off condensation to avoid sludge in the engine. Any thoughts?

I would not listen much to that mechanic. The only way it will boil at 212* if is there is no radiator cap. Anything over 190 is too hot and you need to fix the problem.

 

[VT_Hokie]

The mechanic may have been talking about condensation in the crank housing/ oil pan and getting it hot enough to evaporate off.

Reb, I imagine the hotter you run an engine the more pressure builds up in the cooling system, that is why I did not want to run mine at 230F. I just can trust those idiot lights on older equipment anymore, especially when I found my temp sensor broke during the replacement of the oil pressure sensor.

 

[reb]

The mechanic may have been talking about condensation in the crank housing/ oil pan and getting it hot enough to evaporate off.

Reb, I imagine the hotter you run an engine the more pressure builds up in the cooling system, that is why I did not want to run mine at 230F. I just can trust those idiot lights on older equipment anymore, especially when I found my temp sensor broke during the replacement of the oil pressure sensor.

I guess I wasn't clear in my earlier post. The mechanic was indeed talking about condensation in the crankcase.

I agree with you about the idiot lights. That's why I put gauges on mine. I figure if the engineers who designed the tractor decided the engine could run safely at 230+ degrees (the switch point on the idiot light), I can safely run the tractor at 230 on the gauge. I let it cool off if it starts to creep higher.

 

[clemsonfor]

Im not sure i would be comfortable operating at 230, even if the engineers might have designed it that way, these are 30 yr old machines and you no longer have a warrenty to go back on if you blow it up, if they were wrong. That is unless you recently purchased from one of our dealers (and are under warrenty), and as long as the light was not on you should be good on the replacement.

 

[Cold Camel]

Engines that don't run much can have water condense in the oil. This is very hard on things if the oil does not get above 212 deg. to boil it off. So engines that sit, like boats and tractors need hotter thermostats for longevity. Don't be afraid of 220-230 degs., those are reasonable temperatures.
While overheating an engine can cause acute symptoms and failure, damage from running cool is just as destructive.