JD 650 Overheating - 521 hours - thermostat replace?

[Edensgardener]

Thank you Capricious!

The guys at the radiator shop gave me a cap with a thermostat on it to do just what you're suggesting I think. He mentioned that the sender might be off a bit. He wasn't positive at the temp it should run it - but he estimated 190 or so.

What am I looking for, or finding, if I see bubbles in the coolant?

 

[Edensgardener]

oh - and other than overheating, what would give me reason to suspect the pump - as I can't start up and test temps w/out first replacing the radiator - you're RIGHT I don't want to go through this exercise again! lol

 

[Capricious]

Thank you Capricious!

The guys at the radiator shop gave me a cap with a thermostat on it to do just what you're suggesting I think. He mentioned that the sender might be off a bit. He wasn't positive at the temp it should run it - but he estimated 190 or so.

What am I looking for, or finding, if I see bubbles in the coolant?

Bubbles in the coolant might be indicative of a bad head gasket (bad news) or a cracked casting (very bad news).

 

[Capricious]

oh - and other than overheating, what would give me reason to suspect the pump - as I can't start up and test temps w/out first replacing the radiator - you're RIGHT I don't want to go through this exercise again! lol

If it were me, and If i had done the things you had already done, I would seriously consider changing the waterpump while the radiator is out and the pump is easier to get to. The pump is probably not cheap but you are running out of possibilities. Keep in mind all i have to go on here is the info you posted. If i was there I might see something that would change my mind. (also keep in mind I make no claims of being an expert diesel mechanic)

If it is truly overheating, and if you have had the radiator cleaned (inside and out) and replaced the thermostat, I would guess the pump is the next thing on the list.

I am not familiar with the 650 but i am assuming it does not have anything like a heat exchanger cooler (for hydraulic oil maybe) that could be plugged-up and obstructing coolant flow. And since you were told the radiator didn't look too dirty i am assuming the water jackets in the engine are not plugged-up.

 

[Edensgardener]

I appreciate your help. I mentioned it to my mechanic on the phone the other day and he felt with it only have 500 hours on it - and none of them all of that strenuous that I know of - the pump isn't likely bad. But I don't know what to look/listen for to judge that, either.

I think I'm going to try one more time and take the temp. I'm not sure the water pump is something that I want to try messing with myself, (I'm having a hard enough time with the radiator), anyway, and would let the tractor mechanic do it when he installs the new loader next month. I will def keep the key turned so I can check the light - and use the cap with the therm on it - to monitor. I'll also be sure to double check all of the hose clamps - if air got in there, someone said that could be a problem? IDK - that's why I ask. lol

Anyway - I'm having a very hard time getting the radiator back in tho - I can't seem to get the right angle or something in order to get the fan housing in with the bottom hose attachment on the radiator over it. I'm not sure how in the heck it came out! But it's GOT to go back in!

 

[Capricious]

I would think 500 hrs would be a little soon for a bad waterpump as well. However, usually the two big issues with changing waterpumps are 1) access, which shouldn't be too bad with the radiator out, and rusted bolts/studs, which could still be a problem.

If the tractor is going into the shop anyway for a loader, they can have a look at the cooling problem. My concern is that if this thing has been overheating, and it has apparently done it several times, there may be major damage, either the cause of the overheating, or caused by the overheating.

As for the radiator, well it came out so it should go back in. Sometimes it helps to walk away from a job and let it sit awhile. Go back to it later.

 

[Capricious]

Does this tractor have a clutch-type cooling fan?

 

[Edensgardener]

No, I think it's engine driven. And yeah, last night after about 2 hours - realizing AFTER I had struggled to get the radiator in that I had to take it out to get the fan cover in - I took a shower and went to bed. lol

The holes on the side of the radiator housing didn't seem to match up with those on the frame very well - that was struggle number 1. Took an extra pair of hands to hold UP on the radiator to match the holes while I screwed in the bolts. I nearly cried when I figured out I had to take all of that back out. lol (easy to laugh now!)

Yeah, I know it came out of there - but like I mentioned, I didn't see it come out - someone else had kind of taken over. I may just call them and let them come put it back in. But I don't want the lower hose attatchment bent up like it was on the way out. The radiator shop fixed it once.

 

[Capricious]

"...No, I think it's engine driven..."


Some engine-driven fans have a clutch type hub, which allows the fan to "free-wheel" when it is not needed for cooling. I do not know if this tractor has such a fan clutch.

Assuming the waterpump, fan & V-belt (fan belt) are still all on the tractor, grab the fan (engine OFF, of course) and see if it rotates. If it does not rotate (without the belt slipping on the sheave) then you either do not have a fan clutch, or the clutch has locked-up (which would not be the cause of your over heating). If you CAN rotate the fan without the belt slipping on the sheave (or the crankshaft rotating, i suspose) then you do have a fan clutch, and it is possible it is slipping and not driving the fan fast enough to keep the engine cool.

 

[Edensgardener]

it does rotate, I've had to move it out of the way several times trying to wedge the radiator/shroud back in there.

Maybe a new belt then is in order- especially after I've needed to take it off 2x to get it out of the way. I have to go near the dealer this afternoon anyway. I'll go ahead and pick one up if they have it in stock.

I need to run it before I get the loader on so waiting till that happens isn't much of an option. Soil is perfect for working and down here w/o much rain or too much at once - I wish'd I hadn't taken the radiator out of there now. hindsite.

thank you.