The Famous C4 with EGS

[Jimmy dog]

Hi there iv been reading lots of posts about you have to depressurize and repressurize the actuator system if you need to do any work on it,iv just seen a video on utube where a guy had a leak so his system may not have had pressure anyway,but he installed new pipe and reservoir filled with new fluid,started the car fluid level went down he topped it up and that was it no computer needed and has said he has had no issues since, can anyone confirm if this can be done that the car running does the trick ?????

[Jimmy dog]

Do you actually need diognostics to depressurize and pressure the actuator system

[GiveMeABreak]

The systems should always be bled if the oil is refilled after draining - and the oil is only checked after depressurisation of the piloting actuator in any case to ensure that all the oil from the electrohydraulic actuator unit and the pressure accumulator is returned to the piloting actuator hydraulic reservoir.

The Diagnostic tool like Lexia / Diagbox is used to depressurise the system prior to draining the oil (during a grain and refill operation).
The Diagnostic tool is then used to check the oil level and then when correct (as it has to be depressurised to check the level), the system is then repressurised.

After the oil is topped up and correct and the system repressurised, the hydraulic system has to be bled (again, using the diagnostic tool) which involves cycling through all the gears to force air out the system.

Despite what you see on youtube, not doing so can cause problems with the system....