Flushing hydraulic systems

[Mikey777]

Contrary to the advice of many, resist the urge to flush a closed hydraulic system with diesel fuel. Use only hydraulic oil. The goal is to eliminate contaminants not to introduce even more into the system. If it's an open system and your rinsing during a trans repair or the like use any solvent you desire.
A decent makeshift cleanout filter can be made by putting a scotchbrite sheet inside a suction screen and secure it with wire or tie straps. Just don't leave it in if it plugs too much it can disintegrate and further contaminate the system.

 

[SilentJ]

Good advice. The ONLY fluid that should ever enter your system should be the working fluid. If you need to flush or clean, just drain the oil and refill with new oil, change all the filters, then run the machine , cycle every function, then replace the filters again. Draining the oil and refilling may or may not be necessary

Actually RUNNING a hydraulic system with diesel fuel (eek!) for any length of time can accelerate wear because the components have inadequate lubrication from the diesel. Hydraulic fluid is chosen or a reason

In addition, seals in the hydraulic system may not be compatible with the diesel or other fluid, softening them, hardening them, or even dissolving them depending what you use. Stuff like the epoxy in filter elements (used to join the pleated media to the end of the can for instance) can soften or dissolve adding funk into the system

Only ythe recommended fluid should be used for flushing.

Also, avoid using aftermarket 都nake oil chemicals in your hydraulic oil.

The scotch brite on the suction strainer worries me. Hunks of that can come off and cause more problems. If it plugs even partially, you値l restrict how much oil the suction can get and the pump will cavitate.