Quote:
A mechanic pal told me that there was a little known issue of water contamination in thr trucks. The A/C drain is just above the trans dipstick and if the dipstick seal is compromised, the A/C condensation migrates into the trans. That could be the cause of the rusty areas inside. I'm sure that water mixed with ATF would result in a sludge of some sort.
The fluid FULL level is well above the dipstick seal so any leakage would be fluid coming out, not water leaking in.
Since most cooling systems are an anti-freeze mix it's usually not wet enough to cause rust unless it's nearly pure water; rust can be caused by emersion in water (floods or off-road activity) or the fluid not getting up to full temperature (condensation). Either will cause the fluid to gum up.
The INTERNET, the MISinformation superhighway
| 
