Power steering noise

[Eric.S.]

Hello everyone I was finally able to pick up my grenadier yesterday Unfortunately, I noticed at home that my power steering makes a strange noise. I think it's not a normal noise, or? The filling level in the container was at maximum with the engine warm but switched off. The German instructions do not say exactly in which condition the oil should be checked. Does anyone have an idea? I tried to post a video but I always see the file is too big (7mb)
Thank you

 

[Skydance]

Pressure is defined by the relief valve.

I agree but I don’t think anyone has adjusted it nor has the dealer. There was talk about Agile producing a aftermarket valve sometime ago.

I just found my way much easier. I think the calculation of the reservoir (expansion tank) hasn’t been designed big enough. You fill it upto max and I guarantee it leaks out of the cap through the pin hole and there is nothing wrong with the cap or seal.

 

[SMarshall]

I agree but I don’t think anyone has adjusted it nor has the dealer. There was talk about Agile producing a aftermarket valve sometime ago.

I just found my way much easier. I think the calculation of the reservoir (expansion tank) hasn’t been designed big enough. You fill it upto max and I guarantee it leaks out of the cap through the pin hole and there is nothing wrong with the cap or seal.

That very well could be. And it's my speculation at this point that is the case. That being said I have some further testing to do to prove this theory. I have also acquired a service manual for the Bosch/ZF steering system from a German colleague. It's for a specialty commercial vehicle but the pump and steering box look to be exactly same. It has a flow and pressure specifications including test procedures. And to clarify my comment prior the relief valve determines maximum pressure (while on the steering stops) otherwise the system is operating at system pressure that is regulated via a flow modulation valve. At this point I have no reason to believe there is any pressure or flow issues, simply a capacity issue. I suspect this is due to varying capacity requirements of the steering box in input vs no input phases. But I will dig out the pressure and flow gauges and report back. I am also going to mount a temporary tank level sensor in the reservoir to monitor actual levels in various conditions.

 

[Skydance]

That very well could be. And it's my speculation at this point that is the case. That being said I have some further testing to do to prove this theory. I have also acquired a service manual for the Bosch/ZF steering system from a German colleague. It's for a specialty commercial vehicle but the pump and steering box look to be exactly same. It has a flow and pressure specifications including test procedures. And to clarify my comment prior the relief valve determines maximum pressure (while on the steering stops) otherwise the system is operating at system pressure that is regulated via a flow modulation valve. At this point I have no reason to believe there is any pressure or flow issues, simply a capacity issue. I suspect this is due to varying capacity requirements of the steering box in input vs no input phases. But I will dig out the pressure and flow gauges and report back. I am also going to mount a temporary tank level sensor in the reservoir to monitor actual levels in various conditions.

I believe the electo hydraulic pump is called Dare (Chinese brand) not Bosch but I’m interested in your findings.

 

[SMarshall]

I believe the electo hydraulic pump is called Dare (Chinese brand) not Bosch but I’m interested in your findings.

What scares me, is that if this is a capacity issue, it's also a cavitation issue (potentially if the theory pans out) and in my experience that means people that have had the "whine/noise" for longer periods of time, well more oil may not fix it...

 

[Skydance]

What scares me, is that if this is a capacity issue, it's also a cavitation issue (potentially if the theory pans out) and in my experience that means people that have had the "whine/noise" for longer periods of time, well more oil may not fix it...

Electronic Hydraulic Power Steering Pump Assembly-DARE AUTO

Electronic Hydraulic Power Steering Pump Assembly DARE AUTO is a leading electric hydraulic power steering (EHPS) pump manufacturer in China, mainly supplying automotive OEMs globally. EHPS pump is composed of oil pump, motor, controller, bracket and other parts. DARE is able to design the pump...

www.darepump.com

Similar or same as the Ineos. See what you can make of it.

 

[SMarshall]

Electronic Hydraulic Power Steering Pump Assembly-DARE AUTO

Electronic Hydraulic Power Steering Pump Assembly DARE AUTO is a leading electric hydraulic power steering (EHPS) pump manufacturer in China, mainly supplying automotive OEMs globally. EHPS pump is composed of oil pump, motor, controller, bracket and other parts. DARE is able to design the pump...

www.darepump.com

Similar or same as the Ineos. See what you can make of it.

Cheers. I enjoy a challenge . And moreso making engineers look like wankers but that's a side note