Power steering hydraulic issue

[tim0409]

Hi there

I have a 2017 Doblo van and the power steering has failed four times since I purchased it (new). The main dealers have "repaired" it each time by re-attaching the hydraulic pipe to the cooler - this is attached by a clamp; after the first failure I have continually made the point that they are fixing the failure point and not the underlying cause; it's unlikely that factory and each subsequent mechanic has failed to tighten the clamp properly, and therefore there must be some over pressurisation occurring within the circuit. This is now subject to legal action, but I'm interested in why this is happening. I've researched it online, and from what I gather power steering pumps have a pressure release valve, which when activated allows the fluid to bypass the pump. I wondered if this is the likely cause, or if there is anything else that could be the likely cause?

Thanks

Tim