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D6D engine overheating
- Thread starter .RC.
- Start date
Nige
Senior Member
I concur. That rad won't be flowing air worth a sh1t in the arrowed area.
I wonder what sort of condition the other pulleys are in.?
.RC.
Senior Member
The belts are not bottomed out in the pulley, there is plenty of room for them and the radiator core at the bottom shows sandblasting of the fins mostly, yes they are damaged there, but it is not completely blocked. I did blow it out after I fitted the new baffles.
Nige
Senior Member
Are they the correct belts.? They are sitting awfully low in that fan pulley. Do they sit the same relative way in the crank and tensioner pulleys.?
I don't doubt what you are saying, but the photo you posted shows a radiator plugged with trash in that general area. As @Mobiltech menioned, that won't help with cooling.
Nige
Senior Member
Going back a little bit I noticed that you gave the Part Number of a replacement radiator core as 4N6298. That P/N is not listed for any flavour of D6D that I can see. What's the S/N of your tractor.?
.RC.
Senior Member
It is an early 31X. So that radiator fits from 31X1 to 31X1011. After that they went away with the air to air, air to water combined converter cooler and just had a full length radiator and bigger air to water converter cooler.
I am in denial about the core and going for cheap and cheerful fixes first before I drop 5 grand on a radiator core.
I am in denial about the core and going for cheap and cheerful fixes first before I drop 5 grand on a radiator core.
Last edited:
Nige
Senior Member
I couldn't agree more.
If I was in your position I think I'd be having a close look at the pulleys because, unless those belts in your photo are non-standard, they are sitting too low in the fan pulley despite the fact that according to your inspection they are not yet bottomed out in the root of the grooves.
Check your messages. You have mail.
.RC.
Senior Member
Thanks. I got my air deflector contraption made and bolted it to the front. It certainly deflected the air and now nothing goes around the sides, but seemingly little difference to engine temps. Converter is 3/4 into the green and engine temp gauge is showing on the edge of the red.
I checked the belt. It has been fitted with a 17A belt, so 17mm wide, while the parts book lists a 7M4707 which specs out to 22mm wide.
I could put new belts on it and see I guess.
Had another look at the radiator and I dunno, yes it has some fin damage, the sort of damage you get from pressure washers and general fan blast but I have seen plenty of worse radiators.
I am sure the engine is down on hp, so uses more fuel at lower revs creating more heat, it uses oil and needs to be heated to start it when cold when it should not need heating at all, but does not blow black smoke or fluffy smoke except at the usual revving up stages.
I am still looking at the wrong fins per inch core that has been installed and thinking hmmm.
I checked the belt. It has been fitted with a 17A belt, so 17mm wide, while the parts book lists a 7M4707 which specs out to 22mm wide.
I could put new belts on it and see I guess.
Had another look at the radiator and I dunno, yes it has some fin damage, the sort of damage you get from pressure washers and general fan blast but I have seen plenty of worse radiators.
I am sure the engine is down on hp, so uses more fuel at lower revs creating more heat, it uses oil and needs to be heated to start it when cold when it should not need heating at all, but does not blow black smoke or fluffy smoke except at the usual revving up stages.
I am still looking at the wrong fins per inch core that has been installed and thinking hmmm.
When the belt grooves get worn, the taper of the grooves usually wears the sides curved and not straight so the belts lose some of their grip even though they are not bottomed out which may cause them to slip and glaze.Putting new belts in worn pulleys usually causes the new belt sides to become rounded like the worn grooves until they slip and glaze too. The only answer is to replace the pulleys or if possible re-machine the grooves in the old ones and use new belts. Re-machined pulleys usually require slightly shorter belts
.RC.
Senior Member
If I were to get a new core, choice is steel, brass or copper, increasing in cost from steel to copper and also copper has something like 8 times the thermal conductivity of steel, brass only about two times.
Copper is the softest, while steel the toughest.
From what I can make out the cheap mass produced aftermarket ones are all steel. I can get one of them over half the price of a custom made steel one.
Copper is the softest, while steel the toughest.
From what I can make out the cheap mass produced aftermarket ones are all steel. I can get one of them over half the price of a custom made steel one.
OzDozer
Senior Member
A steel core will give you best protection against sandblasting at the expense of lower heat transfer.
A sandblast grid in front of the core is useful to prevent fin and tube damage from sandblasting.
A copper/brass core with a sandblast grid will provide the best performance overall.
All these older D6's and D7's run hot. Their cooling systems are marginal at the best of times, and your hot climate tests them to the max.
See if there's room in the hardnose to install a larger dimension radiator core. It may involve a bit of additional plumbing.
A sandblast grid in front of the core is useful to prevent fin and tube damage from sandblasting.
A copper/brass core with a sandblast grid will provide the best performance overall.
All these older D6's and D7's run hot. Their cooling systems are marginal at the best of times, and your hot climate tests them to the max.
See if there's room in the hardnose to install a larger dimension radiator core. It may involve a bit of additional plumbing.
OzDozer
Senior Member
You may also like to inquire about a Mesabi tube radiator conversion. They're not cheap either, but they have the advantage of improved cooling ability, the ability to easily replace individual tubes in-situ, and they have better vibration resistance ability, as the tubes are rubber-mounted.
.RC.
Senior Member
Well I have cancelled the appointment with the bank for the loan to buy a new core (I got two prices from a local supplier, one very reasonable at $3600 for a locally made custom one and the other @ nearly $8600 for them to import and supply a genuine Cat core which surprisingly is $2000 more then one from the local Cat dealer.
I pressure washed the core with a little dinky Karcher K2 pressure washer. It is a freaking awesome little bit of gear and stupidly cheap and if it is worth anything I can recommend it. I also tightened the belts, and just installed the air deflector with no radiator guard as I am not doing anything that should damage the radiator unless I go full retard.
Dramatic difference in temps and I did not get the radiator spotless as I ran out of water as I only had 40 litres. Engine was running half to three quarters into the green, and converter was slightly cooler as well about half into the green. It was not hot hot this afternoon. The dozer itself ran like a champion. Quick and snappy gear changes. Not sure if I had positive bias going on as I could see it was not getting hot or it was running better
My only issue now is grass trash getting sucked on and plastered over the radiator. I do have engine guards for the machine that I took off for better airflow. I remember an old contractor we got at times that ran a late model 10K D6C and his machine had covers over the engine that extended up so there was probably only about a 10" gap between bonnet and this guard he had. I have seen D8H's that had full length fenders as well, not that I am doing that.
Other question is are Cat belts worth it? $281 for a set of three (not sure why three as it only uses two) They are only CX section belts. I can get them elsewhere.
One thing that could be done is for improved cooling capacity, install a full width core) the tanks are built for a full width core but 4" on one end is not blanked off for the air portion of the converter cooler. Then you could get a generic oil cooler from somewhere else and mount it somewhere, cooled by electric fans. Not going to be doing that, but it would be possible to improve the cooling capacity.
I know the air deflector looks rough as guts. I did a quick hash job just for proof of concept. It certainly works.
I pressure washed the core with a little dinky Karcher K2 pressure washer. It is a freaking awesome little bit of gear and stupidly cheap and if it is worth anything I can recommend it. I also tightened the belts, and just installed the air deflector with no radiator guard as I am not doing anything that should damage the radiator unless I go full retard.
Dramatic difference in temps and I did not get the radiator spotless as I ran out of water as I only had 40 litres. Engine was running half to three quarters into the green, and converter was slightly cooler as well about half into the green. It was not hot hot this afternoon. The dozer itself ran like a champion. Quick and snappy gear changes. Not sure if I had positive bias going on as I could see it was not getting hot or it was running better
My only issue now is grass trash getting sucked on and plastered over the radiator. I do have engine guards for the machine that I took off for better airflow. I remember an old contractor we got at times that ran a late model 10K D6C and his machine had covers over the engine that extended up so there was probably only about a 10" gap between bonnet and this guard he had. I have seen D8H's that had full length fenders as well, not that I am doing that.
Other question is are Cat belts worth it? $281 for a set of three (not sure why three as it only uses two) They are only CX section belts. I can get them elsewhere.
One thing that could be done is for improved cooling capacity, install a full width core) the tanks are built for a full width core but 4" on one end is not blanked off for the air portion of the converter cooler. Then you could get a generic oil cooler from somewhere else and mount it somewhere, cooled by electric fans. Not going to be doing that, but it would be possible to improve the cooling capacity.
I know the air deflector looks rough as guts. I did a quick hash job just for proof of concept. It certainly works.
OzDozer
Senior Member
Cat belts are no better than any other good brand name, I use Gates belts mostly.
Give me the belt part numbers you want, I might have something. I've got multiple boxes of new Cat belts.
You can't beat a good regular pressure wash through the core. I use a 1000 litre tank and a 50mm firefighter with a centrifugal pump, a good length of 19mm hose - and a nozzle made from the tapered leg of a steel kitchen chair! The nozzle goes down to about 10mm diameter.
Crank the little petrol engine up, throw a handful of powdered laundry detergent (your choice whether to use OMO or SURF, depending on how clean a wash you desire!) - and when that 1000 litre tank is getting well down, your radiator core should be nice and clean!
Perforated engine side screens are the only way to prevent sandblasting and a core filled with trash.
Give me the belt part numbers you want, I might have something. I've got multiple boxes of new Cat belts.
You can't beat a good regular pressure wash through the core. I use a 1000 litre tank and a 50mm firefighter with a centrifugal pump, a good length of 19mm hose - and a nozzle made from the tapered leg of a steel kitchen chair! The nozzle goes down to about 10mm diameter.
Crank the little petrol engine up, throw a handful of powdered laundry detergent (your choice whether to use OMO or SURF, depending on how clean a wash you desire!) - and when that 1000 litre tank is getting well down, your radiator core should be nice and clean!
Perforated engine side screens are the only way to prevent sandblasting and a core filled with trash.
OzDozer
Senior Member
This D6D has the factory perforated engine side screens, but along with the side screens fitted from the factory, you also get a fully perforated bonnet (hood) to ensure maximum air flow. This is not shown in the Grays photos.
.RC.
Senior Member
Those screens are the same as mine. I have the perforated hood as well.
Nige
Senior Member
What Part Number is the set.? I can break that down to a P/N for a single belt or maybe be able to find a different P/N for a set of two.
Dave Neubert
Senior Member
I recently put a newer style transmission cooler on a 977 and did away with the one beside the radiator had to put hydraulic hoses from cooler as the steel lines would not work but it is doing great
Nige
Senior Member
For machines S/N 31X1-1496 I show the Belt Set as 7M-0185 which is a set of 2 belts P/N 6H-5705 for an individual belt. This appears to be for the sound suppression option.
For engines S/N 44V12220-Up (still searching under 31X-prefix here) the Belt Set is shown as 7M-4707 which is a set of 2 belts P/N 4M-4513 for an individual belt.
I can't see a set of 3 belts listed anywhere.
.RC.
Senior Member
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)
Yes that is another option. But you need the part the bigger trans heat exchanger bolts onto as well. A 7N3340 bonnet. Then the bigger 7N3521 heat exchanger. My current heat exchanger is newish going by the fresh yellow paint on it, and it was spotless inside when I was checking that part out.
But there are options for improved cooling capability beyond what the OEM designed in. Depends how much money you want to spend on a 45 year old dozer.