Thread: ACE - So how tricky is it..

Bleeding is meant to be done using a diagnostic tool to fully extend and retract the cylinders during the process to expell all trapped air.

Originally Posted by Hastykiwi

So I have what appear to be some bushes wearing out in the ACE system. Specifically the bush where the front hydraulic ram joins to the short arm. If this is in fact knackered, what is involved in replacing it. The mechanics I have queried have steered me away from this course of action, as they say it is an absolute pain, more so from bleeding the ACE system afterwards. Thye said that they struggle to have a clean bleed and not resulting in all sorts of pump noises. Is this the case or just inexperience/fear on their part?

cheers
NIck

The mechanic probably have got the gadgetry to preform the job.

no harder to bleed than any other hydraulic system, ITs a lot easier if you have the elextronics to make it go up and down all by itself under power but it's still doable.

Below is the ACE bleed procedure from the Blackbox Solutions ACE Module help page. It's a bit fiddly and can obviously be done without a hoist. FWIW there are plenty of stories of people bleeding the ACE system by driving through roundabouts or weaving back and forth on back roads.

LUCAS ACE (SM032)

Hydraulic circuit bleeding: During ACE system maintenance or repair, hydraulic fluid may be lost from the system and air introduced. If air is present in the primary circuit (pump, attenuator and PCV) the system will self bleed shortly after starting the engine. The unwanted air will escape when it reaches the reservoir. When air is in the secondary circuit (actuators and associated pipe work) it is necessary to perform the System Bleed procedure using this function. Both actuators are designed to allow oil and air to flow freely through them when the piston is in the fully extended position. In this position, the air will be forced out and allowed to escape to the reservoir. Using the following procedure, it is possible to bleed the front and then the rear secondary circuits with the front secondary circuit being bled first, but it is critically important that both the front and rear actuators are bled independently.

1. The vehicle should be parked on a good solid 4 post ramp with the handbrake firmly on and in park or neutral.
2. Ensure that the fluid reservoir is kept topped up to the maximum and that the pump is primed (details of how to verify this and perform it can be found in the vehicle's workshop manual).
3. Having ensured that the engine is not running, raise the vehicle on the 4 post ramp to normal underside working height.
4. Disconnect both stabiliser links on the front axle only. Do not disconnect the stabiliser links on the front and rear axles at the same time. Free the nut that holds the silent block at the end of the roll bar.
5. Push the stabiliser link on the torsion bar end up and pull the stabiliser link on the actuator side down simultaneously to fully extend the actuator; make sure that no pipes or hoses become stretched or caught.
   For added safety, lower the vehicle to ground height.
6. Start the engine and whilst it is running, perform the 'Hydraulic Circuit Bleeding' function.
   WARNING: The vehicle may suddenly jerk violently from side to side during this test and so it is vitally important to ensure sufficient clear space around the vehicle.
   The 'Hydraulic Circuit Bleeding' function will take around 10 minutes during which you should ensure that the fluid reservoir is kept topped up. When the 'Hydraulic Circuit Bleeding Function' has ended, turn off the engine.
7. Raise the vehicle on the 4 post ramp again and reconnect the front axle stabiliser links.
8. Disconnect both stabiliser links on the rear axle only. Do not disconnect the stabiliser links on the front and rear axles at the same time.
9. For added safety, lower the vehicle to ground height again.
   Start the engine and whilst it is running perform the 'Hydraulic Circuit Bleeding' function.
   WARNING: The vehicle may suddenly jerk violently from side to side during this test and so it is vitally important to ensure sufficient clear space around the vehicle.
10. The 'Hydraulic Circuit Bleeding' function will take around 10 minutes during which you should ensure that the fluid reservoir is kept topped up. When the 'Hydraulic Circuit Bleeding Function' has ended, turn off the engine.
11. Raise the vehicle on the 4 post ramp again and reconnect the rear axle stabiliser links.
12. Lower the vehicle to ground height and re check the fluid reservoir level.
13. Run all response time tests found in the 'OTHER' section and confirm that they all pass.

so, what are the symptoms of air still trapped in the system??

Originally Posted by Pedro_The_Swift

so, what are the symptoms of air still trapped in the system??

Good question. I had no intention of doing this myself, but was surprised that mechanics were a bit shy about the job as they felt they had little success with the bleeding process. Guess I need to ask another mechanic.
PS I know they have a testbook.

cheers
Nick