D6D engine overheating

[Nige]

The 7M4707 comes up as a set of three on my screen

7M-4707: Cogged V-Belt (Set Of 3)
Width: 22.3 mm (0.88 in)
Brand: Cat
$218.03 (AUD)

In both of the resources I use regularly it comes up as a set of two belts.
Strangely enough in Cat Parts Store it says a set of three belts but shows a photo of two - WTF.?




EDIT: The belts are originally an inch size. Length 80.0" x Width 7/8".

 

[Queenslander]

I know the air deflector looks rough as guts. I did a quick hash job just for proof of concept. It certainly works.

Both our 7H and 6R have this style of slanted, hinged two piece screen.
They work well and allow quick access to wash/blow out the rad.
If I was making them from scratch I reckon I would put a bit more slant on the fins to give a little more protection from sticks etc.

 

[OzDozer]

Nige, this is what I find re the belts ....

4M-4513 is a non-existent part number. 4M-5413 is a V-belt with a size of 71" x 15/16" (1803mm x 23.8mm).

7M-4707 and 7M-4709 appear to be the same belt - 70.98" x 0.88" (1803mm x 22.35mm)

4M-5413 is listed as interchangeable with 7M-4707 and 7M-4709 on some sites.

The set 7M-0185 is listed as 2 belts on the Cat Parts Store sometimes, and 3 belts at other times. The photo always shows 2 belts.

The set 7M-0185 on the CPS shows dimensions as 74" x .88" (1880mm x 22.35mm). Aftermarket suppliers of 7M-0185 state the same length but the width as 15/16" (23.8mm).

Another P/No that has appeared for 7M-0185 is a single belt, 6H5705.
But the CPS says 6H-5705 is obsolete, and it has been replaced by 7M-0185.

 

[Nige]

4M-4513 is a non-existent part number. 4M-5413 is a V-belt with a size of 71" x 15/16" (1803mm x 23.8mm).

Sorry, dyslexia. 4M-5413 in SPS is listed as 1803 x 22.3 (71" x 7/8"). Again my error in crunching the numbers to convert from mm to inches. I was certain that such an old Part Number could not have originally been a metric-sized belt.



Apparently 7M-4709 Belt Set was originally 3H-9861. At CHG01 3H-9861 was replaced by 7M-4707.

 

[.RC.]

Both our 7H and 6R have this style of slanted, hinged two piece screen.
They work well and allow quick access to wash/blow out the rad.
If I was making them from scratch I reckon I would put a bit more slant on the fins to give a little more protection from sticks etc.

That is certainly a good design.

Are you getting much rain? Getting good drops here. Another 30mm last night, and 28mm last Saturday.

It is just a tad green at the moment. Got the truck bogged twice today. Just spinning on top.

 

[OzDozer]

RC, I had a good look through my boxes of Cat fan belts, and sorry to say, I've got nothing in your size.

You're just going to have to trot down to your local Cat dealer with a big jar of lube, and hold onto the counter, and wear the $281 ar*e-reaming for your new Cat belts.

I know you can handle it - you're a big cattle baron anyway, and those cattle prices have been over the top for the last 2 years, so I guess you won't notice the dent in your bank account.


Back in the late 1970's, I recall seeing a crusty old dozing contractor I knew, leaning on the parts counter at Wigmores Tractors, when I went in to pick up some parts for one of my D7F's.

Old Vern had a booming voice at all times, and as soon as he spotted me, he boomed out for everyone to hear - "WHAT ARE YOU DOING HERE? - DID YOU PAY TO GET IN HERE??"

I was a bit taken aback at this line of questioning - but he soon followed up with, "NO - YOU DIDN'T PAY TO GET IN!! - BUT I'LL WAGER YOU'LL BE PAYING DEARLY, BEFORE YOU GET OUT!!"

 

[Queenslander]

Are you getting much rain?

Around 150mm over the past five or six weeks.
Raining again this evening and the forecast sounds promising but we don’t need what they’ve had up north over the past week.
Our country doesn’t look as good as yours yet but we’re getting there.

 

[oarwhat]

So all this and the radiator just needed cleaning???

 

[Nige]

So all this and the radiator just needed cleaning???

Pretty much…….

While the belts are off it might just be an idea to check the profile of all the pulley grooves for signs of wear. @.RC. - that copy of REHS1063 I sent you has a section devoted to inspection of pulley condition. I suggest you use that to check yours because it could be a waste of time putting new belts on overly-worn pulleys.

 

[Queenslander]

Hmmm…, we had Cat give the 7H, in the above pic, a TA2 inspection before we bought it.
Dealer had fitted new genuine belts, so belts and pulleys were given the OK.
With less than a day’s work they started squealing and no amount of adjustment would stop it.
Fan and alt. pulleys were completely clagged.. crankshaft wasn’t too bad.

 

[.RC.]

So all this and the radiator just needed cleaning???

Not really. It has been determined the radiator core is wrong to begin with. It is going to run hot regardless. The belts are wrong. God only knows why 17A section belts were fitted to c section pulleys.
There are the baffles around the fan which are now fixed. There is also the 1.1" hole restriction to slow water going through the radiator. Also the wind deflector, to stop air recirculating.

I do not think it is a wasted thread as I have read many a thread in here, where someone with an issue asks advice. Gets it, then we hear nothing back and the end result is a mystery.

 

[Delmer]

It would have been nice to do the changes one at a time with temperature measurements in between, but it doesn't work out that way very often.

The restriction still bothers me, just as Julian noted in the Acmoc thread. There are plenty of perfectly reasonable explanations of how adding that restriction could improve cooling, but slowing the coolant down in the radiator giving it time to cool off more IS NOT a reasonable explanation. That is a massive error in heat transfer understanding, and makes Julian and I at least, suspect everything about that suggestion.

 

[OzDozer]

It IS a reasonable explanation - and Cat, as well as many cooling experts have espoused this as fact, not theory, for many decades.
It's well known that removing a thermostat (regulator) from a cooling system that is overheating, only makes the problem worse, due to the engineers calculating a certain level of flow restriction created by the thermostat installation.

https://www.motortrend.com/how-to/preferred-engine-coolant-flow-rate/

 

[.RC.]

The restriction still bothers me, just as Julian noted in the Acmoc thread. There are plenty of perfectly reasonable explanations of how adding that restriction could improve cooling, but slowing the coolant down in the radiator giving it time to cool off more IS NOT a reasonable explanation.

By the same token that theory would say my radiator with the bigger gaps at six and a half fins per inch should cool better as more air can flow through it then a nine fin per inch radiator.

 

[Delmer]

It IS a reasonable explanation

Except it violates the basic fundamentals of heat transfer. As Julian pointed out well enough that I can't improve on.

Bringing motortrend magazine into a technical Cat discussion is like going to a Dodge Ram forum for expertise on a technical Cummins question, sorry, not helping. The article's strongest argument is preventing laminar flow, EXCEPT laminar flow is from slower flow, turbulent flow is from faster flow. There are plenty of myths that have been repeated long enough that they are accepted as fact, that's not much proof in my opinion.

Removing a thermostat is a whole different subject, most thermostats we're talking about are bypass type, or a three way valve, open one way cold, open the other way hot. Removing a bypass thermostat opens a short circuit around the water pump reducing flow through the radiator. The article mentions some factual info regarding removing a non bypass automotive thermostat, but that's irrelevant to this.

5:30 for an explanation of bypass thermostats, the rest is standard cooling system info, and a good measure of salesman's claims as well. I'll see if I can find an equally good Cat version.

 

[Delmer]

By the same token that theory would say my radiator with the bigger gaps at six and a half fins per inch should cool better as more air can flow through it then a nine fin per inch radiator.

Wrong. The slowing theory would say that a good coat of dust and lint will improve your radiator cooling by slowing the air to give it enough time to absorb more heat. Using the SAME radiator on the same engine, moving more air through the radiator by moving it faster will make the radiator lose more heat.

You can usually only change one variable at a time to have a valid experiment, adding more surface area is not the same comparison, just like I suggested above.

 

[.RC.]

People can believe what they want to believe. I just want to have a reliable machine with cool air conditioning that I can drive all day in summer.

 

[Welder Dave]

A copper rad can be dipped in solder? (I think) to strengthen the fins. I had that done on my rad. when it was re-cored. I think someone makes a comb for straightening the fins as well. Having all the fins allowing full air flow makes a big difference. Belts sitting higher on the pulleys will make pulleys spin that much faster. I'm not sure if having the fan shroud really tight to the fan is a good idea? It might be better if there is extra air movement outside the fan so the entire rad. surface is utilized. The other thing I'd be concerned with is the mud flap material getting brittle from the heat and cracking and/or potentially breaking. I may be off base but these are things I'd be concerned with.

 

[.RC.]

It got a good run today and it while it never got near the red, it was only 32C today and it still ran hotter then it should have. I did have a good day though until.

Just on dark, in a hurry to just get that one more tree sideways on a slope close to a gully I knew it would not reverse out of with the rake on the front, the downhill track dug in in the soft soil, and the machine would not turn and then the track came off the idler. At least it went inwards against the nose.

Crowbar time tomorrow.

 

[Welder Dave]

That really sucks but it's usually easier to pop back on the idler. Might have to back off the track adjuster and tighten it back up after the track is back on. Too bad it's not in a spot where you could hook a chain to another vehicle. Years ago a neighbor dug a drainage ditch for us. He used a JD555 loader for finish shaping and a track came off. He hooked a chain to his 4x4 pickup pulling the track towards the idler at about a 45 deg. angle. He pulled with the truck and had me slowly drive the loader forward and the track popped back on in about 2 feet.


It sounds like it might be OK as far as temps. are concerned now. Did you check with a heat gun at various places?