Procedure for Bleeding Pump in Mitsubishi
This bulletin applies to 2008-2015 Mitsubishi Lancer Evolution and 2009-2015 Lancer Reliant vehicles. In the case of difficulty bleeding the Active Yaw Control/Active Centre Differential (AYC/ACD) system, the applicable Mitsubishi service manual correctly describes the bleeding procedure necessary when replacing the AYC/ACD hydraulic pump or related components. However, if the system is not properly bled, unusually loud noises will be heard when the pump operates.
A heavy click/clunk noise can be heard after starting the engine and depressing the brake pedal or while the brake pedal is depressed and the engine is then started. The clunk is due to air being trapped in the AYC/ACD system. Continue bleeding until the noise is eliminated.
Automatic transmission fluid (ATF) may not be filling the area below the filter in the AYC/ACD reservoir. If the bottom third of the reservoir is not filled with fluid after pouring ATF into the reservoir, squeeze the large inlet hose several times. This will help displace the trapped air and fill the lower third of the reservoir prior to bleeding the system. It is recommended that you remove the inner trunk panel to view the reservoir.
If you encounter a negative message from MUT3 SE while attempting to start the bleeding procedure, check the steering wheel position. The steering wheel must be at the straight-ahead position for the activation procedure to begin.
Note the area below the filter where air may be trapped.
About the Author
Information courtesy of Mitchell 1
Information for Technical Service Bulletins comes from ProDemand, Mitchell 1's auto repair information software for domestic and import vehicles. Headquartered in San Diego, Mitchell 1 has provided quality repair information solutions to the automotive industry since 1918.
Mike Mavrigian
Motor Age Editor
Mike Mavrigian has written thousands of automotive technical magazine articles involving a variety of specialties, from engine building to wheel alignment, and has authored more than a dozen books that crisscross the automotive spectrum. Mike operates Birchwood Automotive, an Ohio shop that builds custom engines and performs vintage vehicle restorations. The shop also features a professional photo studio to document projects and to create images for articles and books.

