Hi all, I got a new to me D6c dozer last fall. Ran her all winter clearing brush and pushed in a few roads with no problems. Now that its Summer She is getting hot. I am doing some hard ripping and pushing dozing in a building pad. I was wondering what is the proper operating temp for this machine? details: D6c 10k8472 temp reaches 218f +/- and holds dosent boil over as far as i can tell checked radiator tank temp with infrared- matched gauge reading new radiator checked fan blades- in correct pusher position powershift not getting hot- stays far from the "red" zone on gauge when warm and put into high idle and neutral she cools down to 190F within a minute or two another minute shes at 185ish took brush engine guards off- made little to no difference new belt- checked tension good 3500 elevation ambient outside temp 100f Is 218F a okay operating temp or should I be concerned?
218F as a max operating temperature is too high IMO, should be around 200-205 as a max. The fact that it cools down 20 Deg in less than a minute in neutral and High Idle suggests that the radiator & the rest of the cooling system is working pretty well. The $64k question is where the heat is coming from. What about thermostat(s). Have you checked/replaced..? No chance that someone has "turned the wick" up a bit..? What does the exhaust smoke look like..? Another thought. What are you using for coolant..?
What are the condition of the fan and crank pulleys ? Belts ? I know these have been discussed here before
Have not checked thermostats. I guess thats where I should start. The dozer was used as a fireline dozer private contractor before I got ahold of her. dosent puff black smoke under load. a little at idle. not sure what that means.... I did manually let the throttle down a bit to see if I was just pushing her to hard, but got the same results. just took longer to get to overheat temp. as far as coolant I believe its a standard mix of 50/50 glycol. looks the standard green tint I am used to, I was not the one who filled her up last, I just got her last fall. I did just replace a inoperable torque converter temp gauge. is it possible it is reading wrong? where should I check temp with infrared manually on torque converter to make sure the new gauge aint defunct belts new not sure about the crank pulley. how do I check wear ? just look for grooves? I did tighten belt but made no difference. Is there only one thermostat on this machine? The $64k question is actually about $21k Nige, I would have to hunt down a fireline contractor out of ca and beat a thermostat out of him if that was true ; )
Belts should sit up high in grooves of the pulleys. If they’re below the outer edges they could bottom out and be prone to slipping. Look at the bottom of the “V” and see if it is shiny.
Like this ....... a lot of people don't realize that it's the sides of the pulley that transmit the drive to the belt, not the bottom. Be careful though - if someone has fitted an aftermarket belt or belts that are not the correct profile you could get the false impression that the pulleys are worn when in actual fact it's the wrong profile of belt causing the problem. Check the belts and see if they have a Cat Part # or aftermarket. Post any data you find, it might help to identify if they are correct or not.
Have you checked to temperature drop from hose on top of radiator to hose on the bottom? I believe you should be seeing about 15ºF. Nige can you confirm that for me? Also you say the radiator is new, but have you checked to be sure it is nice and clean and not partially plugged on back side? One more thing if this has reversible blades on the fan double check that all are facing the same way, had an over heat of a front end loader that was giving us fits years ago only to find one blade was on "suck" and all others were on "blow".
Personally I'd start with checking coolant strength as from what I read it was not done. Higher ratio of antifreeze to water has poorer heat transfer ability than 50/50. I'd shoot the location of the temperature sensor with a heat gun to verify if gauge is reading correctly or not. Then just the stuff listed above: belts, sheaves, fan condition, airflow thru rads plugged/restricted, thermostats sticking etc.
Thanks for all the suggestions. I will be out at the dozer again in a few days and do some checking.
You might check to see if you have the correct radiator core. You should have one that is 9 fins per inch and 4 rows deep. That's correct for a powershift machine while the standard trans machines only have 3 rows. Sometimes aftermarket companies that sale cores go on the light side to keep the cost down by doing only 7 fins per inch. The fins are where the cooling takes place so if you have less fins you have reduced cooling. If it's hot under load and cools down quickly at idle it may be the core is not large enough. Also check and make sure there isn't any trash in the fins that could be blocking the air flow. James
I have the same machine and have done all the same with the cooling system. Most of it has to do with the pre cup design of the engine. Puts more heat into the cooling system then a DI. Your gonna have to get out of the throttle more and let it breathe on your returns. When it gets into the 90's I have to start watching it. Biggest thing is to keep the radiator clean. I have found that a leaf blower works great.
did you remove(un bolt) the complete engine side shields? in hot weather you have to remove the complete engine brush guards- not just the removable service doors because the fan will pull hot air from along the engine causing it to run hotter under heavy loads. or, try turning the fan to suction and run it for a while- you'll be down to your underwear after about 5 min but the radiator will be pulling ambient air from in front. on old pre-cab machines you either freeze to death or sweat to death except in the spring or fall lol
A very good idea, but one that would only work if the engine has a fan with reversible blades. Not all do AFAIK, and some people have the mistaken impression that removing the fan and turning it front to back then reinstalling will change the air flow direction - it won't. all it will do is make the fan push less air in the same direction towards the blade.
Nige, I agree. I never thought to mention that would work only if the fan is the reversible type. all the ones I ran or worked on at the time had the reversible blades. when I was an operator, we would occasionally shut down, turn the blades and run it for about 1/2 hr just to blow the crap out of the fins before shutting down and turning them back
I did not completely unbolt the side covers, Just took the doors off. Ill give that a try when I get back out to the machine. I will also check the radiator core to see if it is the correct one. as well as replace the thermostat for good measure. Ill update the result as soon as i can. The fan is a reversible type. I will also give that a try if all else fails. I did check the belt pulleys and they seem to be well within spec. The radiator is pretty darn clean. and all fan blades are in correct position. temp gauge was checked with infrared and seems to be correct Thanks everyone for the input, much appreciated.
I would do the easiest stuff first
In summary.....
Old Magnet, do you have the publication number from the book those spec's were copied? I'd like to save them to a folder for future reference!
Form #SENR7593-01 Pages 107 & 111 Testing and Adjustments Service Manual for the D6C Tractor Why not just copy what I posted?
I did that but just wanted to have the original for any other information it might include. I guess I'm somewhat of a information junkie! Just saved that SENR7593, puts most of the information for a 3306 in one nice package, thanks!
Ok I checked thermostat: Good Radiator only has 6 fins per inch. looks to be a 4 core. as Masterlink has stated it should have 9 fins per inch! Tag on radiator core reads 4n-6296 or it is 4n-629s (hard to read) does any body know if these correlate with cat #?
Well SIS NPR says a 4N6296 is a gasket and a 4N0629 is a gear in some governor. Never saw a Cat part number with a letter on the end.
4N-6296 is a good Cat Part Number - the only problem is that it's a gasket...….!! Can you take a photo of the tag and post it..? Edit: We may have a winner - 4N-6298. Radiator Core used on D6C 10K5205-Up
Just looked at the 10K8472 and the radiator core for that is listed as a 4N6298 so for a hard to read tag that might be close enough!
By tractor Serial Number it appears as though that Core is the correct one considering the Part Number. That's not to say there aren't other core options available. The only other thought is that if the core is an aftermarket one simply with a 4N-6298 P/N tag on it for identification purposes of what OEM P/N it replaces then it could be anything ……. Another question to the OP. Have you checked the temperatures of the top and bottom radiator tanks with an infra-red heat gun..?
Here is a pic of tag. I will check tanks with infrared. tried yesterday but was having technical problems with infrared.....
Well that settles that argument - that is NOT an OEM Cat tag. So what you have there in my considered opinion is most likely a "will fit" radiator core of unknown quality and heat transfer efficiency from some aftermarket supplier.
A little more on cores. Six fins is probably aftermarket even though I did find find one for a 5X D6D machine that had 5.5 fins per inch but it was listed as a trash core. Less fins to let the debris flow through was that theory. Most aftermarket manufactures used less fins per inch, thinner headers and maybe thinner fins. Copper or steel fins are an option also. A little less here and there lowers the cost. Usually everything works out OK but sometime it doesn't. Not all aftermarket manufactures are cheap. If you are needing to buy one find out the specs they make there cores to. Of course they'll all say OEM specs so ask them for their dimension. In the 1980-90s the company I worked for (and still do ) sold 6-800 cores a year, all for Cat. Undercarriage was our main business but we had lots of non-undercarriage parts also. Around 2000 we went strictly undercarriage so I haven't dealt with cores since then, but still remember a lot about them. We purchased all our cores from a company called Dynacore. Dynacore was owned by a parent company called General Thermodynamics. GT was OEM supplier to Cat. I did all the purchasing and dealt with the top person at Dynacore. He told me that there was only one assemble process and all cores were built to the Cat specs. They put the cores going to the OEMs in one crate and market it with Cat numbers and information. They put the aftermarket probably in the same crate, and they were really nice crates, but were marked with the aftermarket part number. I never went to the factory so I can't say if that's true but we never had any problems with them and they were the same specs as OEM.