I picked up a neat fluid sampling pump at the local Caterpillar dealership for taking used oil and coolant samples. At first I thought it was a Cat product but on looking it is from the Easy Vac Co. made in the US;
http://www.easyvac.com/index-1.html
I've found that getting component used oil analysis done takes a lot of the guess work out of determining when to change fluids in the PF, especialy in the transmission and transfer case as Matic J and D fluids seem to shear out of grade quickly.
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