Cat Lift Trucks (& Caterpillar) DP40:
DP 40 S6S DIESEL Runs hot after a good workout

Basics all covered.. Checked with mechanical gauge--also used thermometer in filler neck--shows 230-240 degrees. Does not boil coolant and no excessive pressure in system.
Thermostat replaced--water pump--fan Ok--Radiator replaced--
Head removed and checked by very reputable shop, no cracks and resurfaced.
No oil in coolant and no coolant in oil.
Truck runs good and has lots of power, does alright untill you work it hard like loading a flat bed trailer.
Has a good strong airflow out of counter weight, but air is very hot, heats up counterweight to the point, you can't touch it.
This truck has been at the same place for several years and has not had any problems. Over heat condition came up recently.
Even though it runs good, could the injection timimig causing this?
Any Cat guys have any ideas, nothing that has been done has helped.
  • Posted 10 Jul 2008 07:56
  • Modified 10 Jul 2008 09:18 by poster
  • Discussion started by roadrat
  • North Carolina, United States
Showing items 1 - 4 of 4 results.
no problem
good luck
  • Posted 11 Jul 2008 15:13
  • Reply by justinm
  • New York, United States
New York, New York its a heluva town..you know that The Bronx is up..and I'm Brooklyn down
The water pump was replaced.
I have been thinking about the scale build up in the bottom of water jacket, I have seen this before, but had forgotten.
The water in this area is tough on cooling systems.
The exhaust being restricted, very possible, will pass this info along, appreciate the feed back! Will let you know what they find
  • Posted 11 Jul 2008 11:24
  • Reply by roadrat
  • North Carolina, United States
"ARE WE HAVING FUN YET?"
did you check for a plugged exhaust and changed the airfilter?

did you replace or pull the water pump?
how was the impeller?
  • Posted 11 Jul 2008 09:47
  • Modified 11 Jul 2008 09:51 by poster
  • Reply by justinm
  • New York, United States
New York, New York its a heluva town..you know that The Bronx is up..and I'm Brooklyn down
wow looks like you checked it all
hows the motor mounts
some mitsu/cats when the mounts go bad the crank pulley drags on the frame maybe this is slowing the fan down just enough to raise the temp

vapor lock at the pump?
crack the bypass plug see if you get air

scale deposits in the block
clean and flush
a 1/4 inch of scale is equal to adding two inches of steel as far as heat dissipation
but i think the machine shop woulda tipped you off if they seen anything

i have found once or twice after some one changed something used RVT gasket maker and used way too much
one time on an LPG whos regulator kept freezing over
i found RTV from a previous repair had come loose in the water passages and lodged itself in the bypass fitting blocking water flow

just a few ideas hope it helps

i dont know how you could get bad timing without seeing other issues if no has touched the pump to date

after you remove it you need to flow time it
  • Posted 11 Jul 2008 08:03
  • Modified 11 Jul 2008 08:05 by poster
  • Reply by justinm
  • New York, United States
New York, New York its a heluva town..you know that The Bronx is up..and I'm Brooklyn down

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