u/WERTIGO020

Hello everyone, today I want to bring up the topic of bleeding the ACD AYC system.
People often write to me asking for help to write a manual for bleeding the system without using special equipment. I decided to post an instruction on bleeding by hanging the car on a lift.
Important note
If when you turn on the ignition, the ACD AYC error (4wd error) lights up immediately, the bleeding procedure will not help you, do not waste your time and proceed directly to diagnosing the fault codes.

System Bleeding Instructions

Preparatory stage:

1. Install the pump, connect all pipes and hoses.
2. Fill the reservoir with hydraulic fluid.
3. Important: Do not close the reservoir cap; leave it open.
4. Wait 15 minutes.

Stage 1: ACD transfer case bleeding

1. Fully unscrew the bleed nipple.
2. Engage second gear.
3. Start the engine.
4. Begin raising the engine speed from 2000 to 5000 rpm, while simultaneously turning the steering wheel from full left lock to full right lock and back.
5. Watch the fluid level in the reservoir: do not let it run dry, top up in time.
6. Continue flushing the system until a steady stream of fluid without air bubbles comes out of the nipple (initially it may spurt out in bursts).
7. As soon as a steady stream appears, screw the nipple back in.

Stage 2: AYC bleeding

1. The bleeding procedure is similar, but involves two circuits (left and right bleed nipples).
2. Steps:
   · Turn the steering wheel to the left and unscrew the right bleed nipple.
   · Turn the steering wheel to the right and unscrew the left bleed nipple.
3. In each position, repeat the procedure: rev the engine in second gear, monitor the fluid level and wait until all air is expelled.