Possible radiator leak?

[NAVEWO]

My apologies for use of the term "Freon" in the context of my post. When I first dropped off the truck...my service advisor had the service manager come out and look at the "stain". I distinctly recall him saying he could not smell "freon". So I suppose that stuck in my head and I should have used the term "refrigerant" as we were clearly looking at the two condensers to the best of my knowledge through the louvers.

Here is what the service ticket said:
"Customer states sees possible leak on condenser through front lower grill. Verified fluid type stain on condenser, checked ssm's and tsb's, none related to customer concern, hooked up a/c machine to inspect pressures system was not low, vacuumed and recharged both systems to spec, added dye to both systems, performed black light inspection on system, no leaks found at this time, retested system operation, good, system operating normal at this time."

Possibly related???
In August 2024, I took the truck in after a road trip to Phoenix in summer heat and was concerned to see the battery temperature was very high...within the "normal" range but almost touching the upper limit. Here is what that service ticket said:
"Coolant system low, HV battery refrigerant system 2 oz low. High ambient temperatures. Unable to duplicate concern upon arrival. No DTC's present, no TSB's/SSM's apply at this time. Noted coolant level below min level. Filled coolant bottle to max spec. Inspected for leaks, no visible leaks found at this time. R+I 12V battery access cover. Found oil present on HV battery refrigerant system service port caps. Monitored PCM ACRP_B Press PID. PID reading 125 PSI, manifold gauge reading 100 psi, Recovered 0.276 kg R1234YF. R+I frunk trim and stowage bin. Found oil present on 2nd HV battery refrigerant system service port cap. Replaced HV battery refrigerant system low side and both high side service port schroeder valves. Vacuumed and charged refrigerant system with 0.312 kg R1234YF, static pressure 105 psi ambient temperature 85 degrees F. "

I'm not sure there is a path from these previously repaired leaks found in August 2024 down to the condensers where I first saw the "stain" in April of 2026. Maybe the "stain" was from those earlier leaks and I just never noticed. I do not regularly get down on my knees to look through the louvers so that stain could have been there since 2024 maybe??? Now, I do a visual inspection through the louvers and have purchased and installed a Grill Guard. It has not been long but so far, no trace of the stain has reappeared.

Other than the "stain" I've had no trouble with either cabin a/c or battery/motor temps via gauges. Even in high 100 plus temperatures they never seem to rise much past 1/4 way above "normal" and I can usually bring the gauge back down by driving for awhile in either Sport or Tow Haul mode.

These are the "refrigerant" capacities listed in the 2023 Owner's Manual. Maybe someone can enlighten me...trucks with max tow would get the 21.5 oz of refrigerant plus 6.1 oz of oil in addition to the BASE 27 oz of refrigerant plus 6.1 oz oil for the "cabin" system. So does that mean a total of 48.5 oz of refrigerant and 12.2 oz of oil. What is the additional 11 oz of refrigerant and 4.7 oz of oil listed as Battery Cooling System for??? Just curious...I do not have the equipment or skill to touch any of these systems.

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[chl]

There IS a 'freon" based HEAT EXCHANGER to cool down the glycol based coolant.

Yes, Glycol circulates in the HVB and drive motors.

The drive motors have an OIL to GLYCOL exchanger as well, moving the motor heat to the battery pack in winter and further up the coolant conversion process to the freon based heat exchanger to boost heat extraction when the GLYCOL radiator can't cut the mustard.

Item #9

Aha, interesting.
I see now, the refrigerant R-1234yf (Freon substitute) can be used to cool the P-OAT liquid cooling the battery by passing through that item 9 "battery chiller evaporator" controlled by the box labelled 'valve."
I missed that, so I was wrong - the refrigerant IS used to help cool the motor and battery.
My bad.

 

[chl]

My apologies for use of the term "Freon" in the context of my post. When I first dropped off the truck...my service advisor had the service manager come out and look at the "stain". I distinctly recall him saying he could not smell "freon". So I suppose that stuck in my head and I should have used the term "refrigerant" as we were clearly looking at the two condensers to the best of my knowledge through the louvers.

Here is what the service ticket said:
"Customer states sees possible leak on condenser through front lower grill. Verified fluid type stain on condenser, checked ssm's and tsb's, none related to customer concern, hooked up a/c machine to inspect pressures system was not low, vacuumed and recharged both systems to spec, added dye to both systems, performed black light inspection on system, no leaks found at this time, retested system operation, good, system operating normal at this time."

Possibly related???
In August 2024, I took the truck in after a road trip to Phoenix in summer heat and was concerned to see the battery temperature was very high...within the "normal" range but almost touching the upper limit. Here is what that service ticket said:
"Coolant system low, HV battery refrigerant system 2 oz low. High ambient temperatures. Unable to duplicate concern upon arrival. No DTC's present, no TSB's/SSM's apply at this time. Noted coolant level below min level. Filled coolant bottle to max spec. Inspected for leaks, no visible leaks found at this time. R+I 12V battery access cover. Found oil present on HV battery refrigerant system service port caps. Monitored PCM ACRP_B Press PID. PID reading 125 PSI, manifold gauge reading 100 psi, Recovered 0.276 kg R1234YF. R+I frunk trim and stowage bin. Found oil present on 2nd HV battery refrigerant system service port cap. Replaced HV battery refrigerant system low side and both high side service port schroeder valves. Vacuumed and charged refrigerant system with 0.312 kg R1234YF, static pressure 105 psi ambient temperature 85 degrees F. "

I'm not sure there is a path from these previously repaired leaks found in August 2024 down to the condensers where I first saw the "stain" in April of 2026. Maybe the "stain" was from those earlier leaks and I just never noticed. I do not regularly get down on my knees to look through the louvers so that stain could have been there since 2024 maybe??? Now, I do a visual inspection through the louvers and have purchased and installed a Grill Guard. It has not been long but so far, no trace of the stain has reappeared.

Other than the "stain" I've had no trouble with either cabin a/c or battery/motor temps via gauges. Even in high 100 plus temperatures they never seem to rise much past 1/4 way above "normal" and I can usually bring the gauge back down by driving for awhile in either Sport or Tow Haul mode.

These are the "refrigerant" capacities listed in the 2023 Owner's Manual. Maybe someone can enlighten me...trucks with max tow would get the 21.5 oz of refrigerant plus 6.1 oz of oil in addition to the BASE 27 oz of refrigerant plus 6.1 oz oil for the "cabin" system. So does that mean a total of 48.5 oz of refrigerant and 12.2 oz of oil. What is the additional 11 oz of refrigerant and 4.7 oz of oil listed as Battery Cooling System for??? Just curious...I do not have the equipment or skill to touch any of these systems.

Yea, maybe the stains were there from before, but always good to watch for leaks.
There have been a few reports of what smelled like 'Freon" when trying to us the A/C cooling.
I had an intermittent smell like that with no cooling one extremely hot day after parking in the open sun on an asphalt parking lot with the truck off the first summer I had the truck.

Now I keep the truck on with A/C running in the summer when I park in the sun at a shopping center for example, to keep everything cool, battery and cabin.

 

[MountainAlive]

I was going to ask if anyone knows how the whole heating/cooling system works on a max tow and now I regret that thought.

 

[TaxmanHog]

I was going to ask if anyone knows how the whole heating/cooling system works on a max tow and now I regret that thought.

We don't have exact diagrams of the Max Tow system.

The first graphic I pasted above is actually from a MME, we speculate that Lightnings without max tow are designed in the same fashion.

What would be distinct on MAX tow trucks is a second AC compressor which is directly connected to the chiller {#9} with no diversion piping between the primary AC compressor which would then have the sole task of cooling the cabin.

 

[chl]

We don't have exact diagrams of the Max Tow system.

The first graphic I pasted above is actually from a MME, we speculate that Lightnings without max tow are designed in the same fashion.

What would be distinct on MAX tow trucks is a second AC compressor which is directly connected to the chiller {#9} with no diversion piping between the primary AC compressor which would then have the sole task of cooling the cabin.

That's where my confusion came from...
I've read this but never found a diagram of the whole shebang:

"Upgraded Cooling System: Adds a secondary battery cooling loop, high-capacity radiator, and specialized cooling lines to the battery pack. This prevents battery thermal throttling under heavy, sustained loads..."

Maybe a parts supply site or a service manual would have an image - just haven't located one yet...a lot of images to sort out, just haven't had the time...

https://www.google.com/search?sca_e...2ahUKEwiYxsS97YSVAxU-MlkFHYaVPT4QuIIBegQIOxAA

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