GUIDE-VALVE 1916766 - Caterpillar

Some Caterpillar products use oil coolers which are constructed with nonmetallic parts. These oil coolers are referred to as "Rubber End Sheet" oil coolers because the end plates, which support the tubes, are of a rubber like material instead of metal. There are also nonmetallic baffle plates inside these oil coolers.
Incorrect cleaning solvents can damage these baffle plates. The most common ways of cleaning engine, transmission and hydraulic oil coolers are steam cleaning, caustic solutions and various solvents. Normal hot caustic solutions used on "boil out" tanks do NOT affect the materials in these coolers. Oakite and Magnus brand caustic solutions have been tested and do not damage the parts. Such caustic solutions must be flushed out with a suitable solvent. Some solvents can affect the nonmetallic baffle plates. The baffle plates may swell and crack if an incorrect solvent is used.
The exterior of the coolers can be cleaned with steam. However, do NOT blow the steam into the oil passages or on the ends of the coolers. This can damage the baffles or end plates.
DO NOT use chlorinated solvents when flushing oil coolers with rubber end sheets. Use only solvents of the mineral spirits family. Stanisol is an acceptable mineral spirit solvent. Use the solvent only as long as needed. The oil cooler must be completely flushed with clean water after a solvent has been used. Use compressed air to dry the oil cooler and apply a rust preventive if the oil cooler is not to be installed immediately.
If vendors are cleaning or flushing oil coolers for you, check to see what solvents they are using before sending them rubber end sheet oil coolers.