Thexton Manufacturing Co. introduces the DEF-Chek Tester, No. THX 108, a Diesel Exhaust Fluid (DEF) tester that features urea concentrate testing and temperature compensating discs that test DEF hot or cold. If mixture is 0.7 percent off, the manufacturer suggests replacing DEF and identifying why concentrate is off. If the DEF concentrate is not correct, injectors may become clogged and DEF will not work properly.
