Why is the oil in my BUSCH R5 Oxygen RA 0400 C Water Pump black?
- NNicole ChavezAug 12, 2025
If the oil in your BUSCH Water Pump is black, it could be due to a few reasons. One possibility is that the oil change intervals are too long, in which case you should flush the machine (contact Busch). Another reason could be a defective inlet filter (optional), which should be replaced. The machine running too hot can also cause the oil to turn black; refer to the troubleshooting steps for "The machine runs too hot".