Cooling system questions on my D4 (7J5052)

There definitely is meant to be a thermostat fitted to that D4, it is located at the junction of the top water pipe from the motor, and where it connects to the top radiator tank.

On my D4 7J, and D4 2T one had none, while on the other tractor the thermostat was busted open by a rough nut operator. You will need to remove the radiator to access it (not a big job), and then you will find they are secured by a brass locating ring that can be a pain to remove until you buy, or fabricate a simple tool.

CCJersey has the photo of the tool he made to remove that locking ring I reckon, it is a repair well worth doing because temperature is critical to all motors. I fabricated a simple slide hammer to pull mine out.

If you are worried about winter freezing your coolant I'd drain the whole system, or use a good quality ani freeze, I've not heard about using lubricating fluids, though I recall my Dad (who was a Mechanic) using a few teaspoons of Brake Fluid in a older car radiator to lubricate a squeaking water pump!
regards
Mike.

There definitely is meant to be a thermostat fitted to that D4, it is located at the junction of the top water pipe from the motor, and where it connects to the top radiator tank.

On my D4 7J, and D4 2T one had none, while on the other tractor the thermostat was busted open by a rough nut operator. You will need to remove the radiator to access it (not a big job), and then you will find they are secured by a brass locating ring that can be a pain to remove until you buy, or fabricate a simple tool.

CCJersey has the photo of the tool he made to remove that locking ring I reckon, it is a repair well worth doing because temperature is critical to all motors. I fabricated a simple slide hammer to pull mine out.

If you are worried about winter freezing your coolant I'd drain the whole system, or use a good quality ani freeze, I've not heard about using lubricating fluids, though I recall my Dad (who was a Mechanic) using a few teaspoons of Brake Fluid in a older car radiator to lubricate a squeaking water pump!
regards
Mike.

[quote="Mike Meyer"]There definitely is meant to be a thermostat fitted to that D4, it is located at the junction of the top water pipe from the motor, and where it connects to the top radiator tank.

On my D4 7J, and D4 2T one had none, while on the other tractor the thermostat was busted open by a rough nut operator. You will need to remove the radiator to access it (not a big job), and then you will find they are secured by a brass locating ring that can be a pain to remove until you buy, or fabricate a simple tool.

CCJersey has the photo of the tool he made to remove that locking ring I reckon, it is a repair well worth doing because temperature is critical to all motors. I fabricated a simple slide hammer to pull mine out.

If you are worried about winter freezing your coolant I'd drain the whole system, or use a good quality ani freeze, I've not heard about using lubricating fluids, though I recall my Dad (who was a Mechanic) using a few teaspoons of Brake Fluid in a older car radiator to lubricate a squeaking water pump!
regards
Mike.[/quote]

Thanks Mike, I should not have been so lazy and taken a look at the service manual, there's a picture of it there😞 Mine's either missing or busted/failed open. It looks to me like the cast iron top water pipe can be removed without removing the radiator, but it's no real bother as I have a small 360 excavator that doubles up very nicely as a 1 ton crane! (health and safety not looking, obviously)

Are they a standard automotive type 'stat, like found maybe in a big-block Mopar, or are they a specialist Cat thing?

Cheers Julian.

Julian.

Hi Julian, Nothing special about them, except the removal process!!! Take the old one to a local auto shop, I expect someone here will chime in with the temperature they normally open on the old Cat diesels.

I think I paid about $25 for a aftermarket one here in Oz, but you might be surprised and find your local Cat Dealer selling them for 6 pounds. Their pricing of parts is often illogical I've discovered.

I think you will need to remove the radiator, or at least loosen it on it's mounting bolts for this job because you will wreck your new gasket that seals the face between the upper water manifold and the top radaiator tank as you slide the water manifold back into place, it's a snug fit there.

Mind your toes when playing with that radiator, it's not like a little Morris Minor's, as you know😆
regards
Mike

The job's been a bit slow of late due to work and other stuff but today I removed the rad to fit a new thermostat. There was no 'stat fitted.

I ordered a thermostat (regulator) and 'retainer' part number 2A1159 from the local Cat dealer. The retainer part number had changed, so I was told, to 4F7390 which to my surprise turns out to be a thick 'O' ring.

The O ring is a good size for the job, but it's not going to be of any use on its own. I'm wondering how to sort this out now for the best, it would be an easy job to cement the thermostat in place with some epoxy, or maybe I need to make a steel ring from an off-cut of pipe or tube that I can drive in to 'nip' the thermostat up to the 'O' ring. Maybe the dealer has given me the wrong part - I don't think 'O' rings had been invented in 1941 but that's not to say that Cat introduced them by way of a replacement.

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Cheers Julian.

That "O" ring is just a spacer, originally they were metal and a very tight fit, hence the need for a special tool to remove them.

Place the thermostat in that housing first, then the "O" ring, I'm guessing that "O" ring butts up against the top radiator tank keeping the "Regulator" snug up against the shoulder in that top water manifold.

I read here or on ACME a while back someone complaing that CAT. Inc. no longer supplied that metal locking rings, hence the rubber "O" ring solution.

It should work OK.
regards
Mike

[quote="Mike Meyer"]That "O" ring is just a spacer, originally they were metal and a very tight fit, hence the need for a special tool to remove them.

Place the thermostat in that housing first, then the "O" ring, I'm guessing that "O" ring butts up against the top radiator tank keeping the "Regulator" snug up against the shoulder in that top water manifold.

I read here or on ACME a while back someone complaing that CAT. Inc. no longer supplied that metal locking rings, hence the rubber "O" ring solution.

It should work OK.
regards
Mike[/quote]

Mike, that was my initial thought. The trouble is that the thermostat abuts against a shoulder cast into the pipe, this shoulder is about 1/2'' down (as shown in my picture) so that 'O' ring is not going to do the job - not by a long shot.

It looks like the housing is 2.5" internal diameter, so I'm going to look for a bit of (say) scaffold tube that I can cut a slice off of to act as a spacer.

Cheers Julian (rather confused now:lol😊

One thing I do with those "regulators" as Cat calls 'em is to drill a small hole, 3/32" or so in the movable plate. That helps bleed air out when refilling with coolant, also open the vent cock on top of the pony (if yours has it).

I went through the exact same procedure when I did my "regulator " on the D4 2T. The parts guy told me the number for the "retainer" had been updated. The only number he had refered to a "ring". When the part got here it was a rubber O ring. Which someone has pointed out, is NOT nearly thick enough to work. When I went back, another parts guy said he could still get the original retainer number from Morton, Ill. for $53.00. I took mine to a guy who brazed it back together for $10.00. I think I can make it work. Maybe this weekend!! It never hurts to double check when the parts numbers change. The new number for the engine oil filter turns out to be a hydraulic filter for who knows what. Anyway good luck on your project.