What Did You Do With Your Aux Cooling System

[Ronmar]

Yea,I havn’t seen anything like that in any of my wanderings thru the drawings… ecm fan control feeds the fan solenoid and the aux fan relays in parallel/simultaneously via the fan override switch.

one thing the ECU may do is be predictive and roll on the fan earlier than 205 based on rate of rise. or yours isn’t programmed for 205… Or the MMDC isn’t accurately displaying the bus temp data on the temp gauge…

 

[aw113sgte]

Yea,I havn’t seen anything like that in any of my wanderings thru the drawings… ecm fan control feeds the fan solenoid and the aux fan relays in parallel/simultaneously via the fan override switch.

one thing the ECU may do is be predictive and roll on the fan earlier than 205 based on rate of rise. or yours isn’t programmed for 205… Or the MMDC isn’t accurately displaying the bus temp data on the temp gauge…

In normal conditions it very reliably kicks on at 205. It could be a rate of rise..or trans temp..not sure and ultimatly I don't think it's very important. Maybe an MTV thing, but how much data do we really have of lmtv at 30.4k going wot up a steep hill in second?
Just sharing my anecdotal experience.

 

[dwlindsey]

Yea,I havn’t seen anything like that in any of my wanderings thru the drawings… ecm fan control feeds the fan solenoid and the aux fan relays in parallel/simultaneously via the fan override switch.

one thing the ECU may do is be predictive and roll on the fan earlier than 205 based on rate of rise. or yours isn’t programmed for 205… Or the MMDC isn’t accurately displaying the bus temp data on the temp gauge…

I get my M1088 delivered in a few days. I'm going to delete the Aux Transmission Cooler. How, where, do I find the information about what to do with the hoses? Is there a schematic in the TMs? I'm only just starting to read them. A pointer to the specific TM and section regarding the Aux Transmission Cooler would be very helpful.

 

[Ronmar]

I haven't found too much schematic info on the aux cooler plumbing, what i know i have gleaned from pics and discussions with those who have deleted or modified.

basically you have an output and an input line on the right side of the trans. These connect to a thermal mixing valve with an internal thermostat. The mixing valve in turn has 2 ports with hoses that flow forward to the cooler on the radiator output, and 2 more ports that have hoses to the aux cooler….

you need to disconnect it all, and run a hose from the trans output port to the passenger side front heat exchanger port, and run another line from the drivers side heat exchanger port back to the transmission input port…I believe the trans ports are labeled on the trans…

have no idea wether the installed hoses are long enough to re-connect trans to forward heat exchanger directly, so you may need new hoses.

I am thinking these are all -12 male ports to female hose ends, but don’t quote me on that

EDIT: Specs for one of the hose part numbers says its a 37Deg flare, 1.31" X 12 Threads per inch, which works out to be a -16JIC?

 

[dwlindsey]

That's very helpful. If I read it correctly, I'll just need two hoses: 1 from the trans output port to the passenger side front heat exchanger port, and run another line from the drivers side heat exchanger port back to the transmission input port. After I pressure wash the truck, I'll try to sort out exactly where those 4 ports are. Thanks!

 

[Ronmar]

That's very helpful. If I read it correctly, I'll just need two hoses: 1 from the trans output port to the passenger side front heat exchanger port, and run another line from the drivers side heat exchanger port back to the transmission input port. After I pressure wash the truck, I'll try to sort out exactly where those 4 ports are. Thanks!

Here is the front cooler only 2 hose installation on the 1078/1079… parts 10 and 20…