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

 

[Clark Kent]

The CAAS Dare Fuxim is the manufacturer, Made in China. Going by their web site and some other sites their large 1Kw electrohydraulic pumps as well as their small models are external gear type pumps electronically controlled using CAN, speed, steering angle and pump motor position detection. Being an external gear type pump the displacement will remain constant every revolution with the system using speed of the pump to control the flow. 12Mpa maximum operating pressure 11L/m flow. From info on their site the pressure and flow compensation are achieved electronically from inputs from road speed, steering angle. The pump will have an internal relief valve for over pressure to protect the pumps hydraulic circuit when required.
With the pump being electronically controlled and some dealers suggesting there is no issue with the pump could the issue lie with the electrical supply ie connections, control software or sensor input errors not ramping up the pump speed enough or too slowly to meet the flow demands of the steering hydraulic system?
On a side note, Dare Fuxim share prices look to be performing well.

Good info, thanks @NQ94. The demand-based ramping of the motor speed goes some way towards explaining the frequency changes as load comes on and off the steering box. It sounds like the motor speed anticipates the demand by reading the steering angle sensor so the pump pressure doesn't lag behind the turning effort. That control loop may also explain why the steering can feel heavy during low speed high angle turns, like parking, where the steering can feel under-boosted.

I take it the pump switches location on LHD and RHD vehicles? Does the location of the pump on LHD vehicles make it somehow more audible? Are there other components around or near the pump that mask the whine in RHD models? Or is the piping run on LHD longer or different somehow contributing to the issue?

Most of the reports of this issue are coming from LHD markets on gas/petrol models.

Good question @Shopkeep. That was speculated when the NA market started getting their vehicles and noticed the noise level. The LHD PS motor and pump are located on the RHS of the vehicle, opposite to RHD vehicles, so the diagonal distance and structure between driver and pump is about the same for both configurations. The NA vehicles seem louder but there's not yet been a clear correlation why. Running time (pump age) has helped calm some vehicles down but it's such a subjective thing it's hard to compare or draw a line despite IA attempting to nominate an acceptable dB level.

 

[Shopkeep]

Mine is a Diesel RHD (pump located on the left in front of passenger) and makes the noise. Very noticable with the window down.

Is it a "hear you coming from a mile away" kind of noise noise or a "oh yeah now I know what they are talking about driving slowly windows down in an under ground carpark or narrow walled street" kind of noise? I had the latter early on but it settled down to barely noticeable with age.

 

[Cruisey73]

Is it a "hear you coming from a mile away" kind of noise noise or a "oh yeah now I know what they are talking about driving slowly windows down in an under ground carpark or narrow walled street" kind of noise? I had the latter early on but it settled down to barely noticeable with age.

Good to hear it settled down for you. How many K's did that take? You can hear it across the street and when driving up to about 40kph. It's not totally obnoxious, but definitely noticeable. It's probably the high-pitched squeal that's annoying rather than the volume.

 

[Shopkeep]

Good to hear it settled down for you. How many K's did that take? You can hear it across the street and when driving up to about 40kph. It's not totally obnoxious, but definitely noticeable. It's probably the high-pitched squeal that's annoying rather than the volume.

I never found the pump noise overly annoying or unusual but it was definitely more noticeable during the first three to six months of ownership. Now eighteen months or so down the track I don't notice it unless I am in an underground car park windows down and even then its a subtle whine (no one ever looks my way wondering WTF is that noise). The diesel engine is much noisier than the gas/petrol version so probably masks the whine to a large extent.

 

[Skydance]

I take it the pump switches location on LHD and RHD vehicles? Does the location of the pump on LHD vehicles make it somehow more audible? Are there other components around or near the pump that mask the whine in RHD models? Or is the piping run on LHD longer or different somehow contributing to the issue?

Most of the reports of this issue are coming from LHD markets on gas/petrol models.

it affects LHD and RHD, diesel or petrol. But only some. Some louder than others. Since reducing my fluid levels, the noise level of the power steering is quieter than the engine. It still makes a noise but it’s not distinctly noticeable as before.

 

[Skydance]

I would also say this which is controversial and you never believe me. The power steering fluid level does have an effect on the handling of the Grenadier. If you over fill the fluid, the steering wanders, lots of correction on undulating roads, dead steering feel.

Since reducing the fluid to just over min, the steering lock to lock feels more positive, more accurate, less play and dare I say slightly better return to centre. So more confidence around corners and no high speed wandering. I also own another live axle 4x4 so I know about the differences in handing between the Grenadier and a SUV.

This will only make a difference if the reservoir is overfilled in the first place and therefore won’t benefit all.

Sometimes you hear YouTube reviewers saying the Gren wanders at high speed and I bet many of you will say but mine doesn’t. So we all have the same steering pump (albeit not a very good one), the only variable is load, weight, trapped air and fluid levels. Is there a pressure valve on the pump and has anyone adjusted it?

 

[Skydance]

Is it a "hear you coming from a mile away" kind of noise noise or a "oh yeah now I know what they are talking about driving slowly windows down in an under ground carpark or narrow walled street" kind of noise? I had the latter early on but it settled down to barely noticeable with age.

So mine too after 10k miles, 2 years of driving the noise got quieter compared to new because the air in the system has dissipated and therefore fluid levels has dropped.

How I discovered fluid level makes a difference, after my recent service they topped up all the fluids and I noticed the difference in both the noise and feel. It was like new again, you could hear my steering noise from around the block.

 

[Tom109]

How I discovered fluid level makes a difference, after my recent service they topped up all the fluids and I noticed the difference in both the noise and feel. It was like new again, you could hear my steering noise from around the block.

I had my 12k service in February. The tech said my PS was quieter then most, and that they bled the system anyway, but no change. The returned fluid level is just over min.

 

[Skydance]

I had my 12k service in February. The tech said my PS was quieter then most, and that they bled the system anyway, but no change. The returned fluid level is just over min.

This is good and I would leave it that way. Your tech is right. If you try topping it up to max or slightly over, I bet the noise gets louder and your steering feel more wallowy.

 

[NQ94]

I should join the "Dull Men's Club" after reviewing the thread and videos and finding that there have been very limited reports of pumps totally failing. This steering noise issue has intrigued me as I regularly work with hydraulic systems and various hydraulic steer systems from full hydraulic to power assist systems like the Ineos design. After putting in excessive time researching the issue it looks like the Jeep Wrangler JT and JL uses the same family of pumps as the Grenadier with the Gladiator having the closest porting lay out. There is five or six different part numbers for the various Jeeps and years. Going off to various open Jeep forums, videos and articles it appears that some Jeep owners are experiencing the same issue as some Grenadier owners, this may have been previously mentioned.

I borrowed some photos from around the forum, the net and online stores to show some details. Some observations that were noted is looking at the Jeep Gladiator pump photo next to the Ineos pump the only major difference is the black end cover and it's porting. There are no assembly cross section drawings or parts kits easily available, and the pump is changed as a complete unit. The unit shares very similar design features with other brands of EHPS and with some searching there are videos and articles where people have disassembled pumps. The pump used in the Grenadier follows a pretty standard lay out and features with the black end cover the reservoir as well as the cover for the hydraulic pump which is submerged hydraulic oil supported by the hydraulic pressure relief valve being in the housing that the black cover bolts to. The electric motor in the centre section and the rear section being the sealed motor control and electronics section. The electrical inputs are a high current circuit and a CAN circuit for controlling the pump. If the CAN protocol on the Jeep and the electrical connections are the same as the Grenadier this pump theoretically could be interchangeable. People are changing the Jeep ones in their garage with what seems to be no reprogramming.

There has been a good deal of information on symptoms other than the noise relating to the noisy steering pumps. I have previously suggested electrical connection issues similar to some faulty Jeeps that could affect pump speed and early in the thread I did suggest possible hydraulic issues particularly in the relief circuit and relief pressure settings. The Jeep version images, and likely no change on the Grenadier version, show these pumps have the most basic spring poppet style relief valve. This type of non-adjustable pressure relief valves is not the best design and it is common to have variances from unit to unit as they depend on a good seat in the pump housing and good spring pressure and generally relive back into the inlet port of the pump. Poppet relief valves are generally for spike protection of the hydraulic system and are noisy, generate considerable heat and fluid turbulence if constantly operating partially open. This could be easily checked at the valve by operating the steering system with normal type driving and not holding on the steering stops. If this valve is continually going over relief the valve and the area around the valve will be considerably hotter than the rest of the pump.

There is a product in the Jeep community that is replacement adjustable steering relief valve or what they call Steering Booster Valve for the steering pump. Once fitted this valve that can increase hydraulic pressure to 2000psi 13.7Mpa to increase steering performance for large tyres and heavy steering loads. This could be beneficial for the pump fitted to a Grenadier not by increasing pressure but by having a better design and being adjustable to the correct and stabilise OEM pressure, keeping the poppet seated for pressure spikes and letting the electronics control the pump and remain as the primary control.







Left Grenadier Electrohydraulic Power Steer Pump EHPS

Jeep Gladiator Pump

 

[Skydance]

I should join the "Dull Men's Club" after reviewing the thread and videos and finding that there have been very limited reports of pumps totally failing. This steering noise issue has intrigued me as I regularly work with hydraulic systems and various hydraulic steer systems from full hydraulic to power assist systems like the Ineos design. After putting in excessive time researching the issue it looks like the Jeep Wrangler JT and JL uses the same family of pumps as the Grenadier with the Gladiator having the closest porting lay out. There is five or six different part numbers for the various Jeeps and years. Going off to various open Jeep forums, videos and articles it appears that some Jeep owners are experiencing the same issue as some Grenadier owners, this may have been previously mentioned.

I borrowed some photos from around the forum, the net and online stores to show some details. Some observations that were noted is looking at the Jeep Gladiator pump photo next to the Ineos pump the only major difference is the black end cover and it's porting. There are no assembly cross section drawings or parts kits easily available, and the pump is changed as a complete unit. The unit shares very similar design features with other brands of EHPS and with some searching there are videos and articles where people have disassembled pumps. The pump used in the Grenadier follows a pretty standard lay out and features with the black end cover the reservoir as well as the cover for the hydraulic pump which is submerged hydraulic oil supported by the hydraulic pressure relief valve being in the housing that the black cover bolts to. The electric motor in the centre section and the rear section being the sealed motor control and electronics section. The electrical inputs are a high current circuit and a CAN circuit for controlling the pump. If the CAN protocol on the Jeep and the electrical connections are the same as the Grenadier this pump theoretically could be interchangeable. People are changing the Jeep ones in their garage with what seems to be no reprogramming.

There has been a good deal of information on symptoms other than the noise relating to the noisy steering pumps. I have previously suggested electrical connection issues similar to some faulty Jeeps that could affect pump speed and early in the thread I did suggest possible hydraulic issues particularly in the relief circuit and relief pressure settings. The Jeep version images, and likely no change on the Grenadier version, show these pumps have the most basic spring poppet style relief valve. This type of non-adjustable pressure relief valves is not the best design and it is common to have variances from unit to unit as they depend on a good seat in the pump housing and good spring pressure and generally relive back into the inlet port of the pump. Poppet relief valves are generally for spike protection of the hydraulic system and are noisy, generate considerable heat and fluid turbulence if constantly operating partially open. This could be easily checked at the valve by operating the steering system with normal type driving and not holding on the steering stops. If this valve is continually going over relief the valve and the area around the valve will be considerably hotter than the rest of the pump.

There is a product in the Jeep community that is replacement adjustable steering relief valve or what they call Steering Booster Valve for the steering pump. Once fitted this valve that can increase hydraulic pressure to 2000psi 13.7Mpa to increase steering performance for large tyres and heavy steering loads. This could be beneficial for the pump fitted to a Grenadier not by increasing pressure but by having a better design and being adjustable to the correct and stabilise OEM pressure, keeping the poppet seated for pressure spikes and letting the electronics control the pump and remain as the primary control.







Left Grenadier Electrohydraulic Power Steer Pump EHPS
View attachment 7898315View attachment 7898316
Jeep Gladiator Pump
View attachment 7898328

So would you say the whining noise and seepage (reservoir cap through the vent hole) is caused by too much pressure and it wasn’t designed properly. Would a shortened pressure release valve work or maybe a bigger expansion tank ie the reservoir?

 

[NQ94]

So would you say the whining noise and seepage (reservoir cap through the vent hole) is caused by too much pressure and it wasn’t designed properly. Would a shortened pressure release valve work or maybe a bigger expansion tank ie the reservoir?

This is only my opinion. Even though the steering system is pretty heavy I don't think the system is poorly designed, it's near identical to Jeeps system and they don't seem to have too many issues for the number of cars sold. The caps vent to atmosphere so like other power steering systems there may be fine oil vapour released around the vent leaving a stain. If it's dripping or pouring oil that could be a symptom of another issue.
I do believe the pumps with issues need a gauge connected on the outlet and the working pressure and temperature checked. The pumps that are noisy and have no other mechanical issue or failure may have the relief pressure too low and require it to be raised. The pump is primarily controlled electronically so if the hydraulic load is too low the algorithm may ramp the pump speed higher to maximum to compensate for internal hydraulic leakage in the pump or steering box. There is possibly no fault code for pump at maximum speed low electrical load, I have not checked any generic code lists.

I have added a generic electronic steering video

View: https://youtu.be/b-KIM-hpwCY?si=jbLEEvBYLKvfloFc

 

[Zimm]

so basically you're suggesting some high frequency valve chatter. it definitely would account for the variation reported, and a symptom varying as the valve wears and ages.

 

[Zimm]

The gladiator pump had looked like a dead ringer to me. what variation do you see?

 

[NQ94]

The gladiator pump had looked like a dead ringer to me. what variation do you see?

I would say dead ringer except for the black end covers. Really need both on a bench together and disassembled to properly confirm.

 

[Zimm]

This is some seriously good forensic work BTW. In case anyone isn't understanding, blow up a balloon and pinch the end letting the high pressure air out, and listen to the wonderful music of it squealing. This makes so much sense, ya pretty much have to prove to me it isn't the issue. We may need to pin an Ineos medal on NQ94's chest.

 

[Zimm]

I would say dead ringer except for the black end covers. Really need both on a bench together and disassembled to properly confirm.

I bookmarked the valve. If mine gets worse I'll just try it. right now mine has gone from silent to slightly squealy. I need to ask she zimm if its bad, as it may be in one of those pitches old damaged ears don't register well.

 

[Shopkeep]

I should join the "Dull Men's Club" after reviewing the thread and videos and finding that there have been very limited reports of pumps totally failing. This steering noise issue has intrigued me as I regularly work with hydraulic systems and various hydraulic steer systems from full hydraulic to power assist systems like the Ineos design. After putting in excessive time researching the issue it looks like the Jeep Wrangler JT and JL uses the same family of pumps as the Grenadier with the Gladiator having the closest porting lay out. There is five or six different part numbers for the various Jeeps and years. Going off to various open Jeep forums, videos and articles it appears that some Jeep owners are experiencing the same issue as some Grenadier owners, this may have been previously mentioned.

I borrowed some photos from around the forum, the net and online stores to show some details. Some observations that were noted is looking at the Jeep Gladiator pump photo next to the Ineos pump the only major difference is the black end cover and it's porting. There are no assembly cross section drawings or parts kits easily available, and the pump is changed as a complete unit. The unit shares very similar design features with other brands of EHPS and with some searching there are videos and articles where people have disassembled pumps. The pump used in the Grenadier follows a pretty standard lay out and features with the black end cover the reservoir as well as the cover for the hydraulic pump which is submerged hydraulic oil supported by the hydraulic pressure relief valve being in the housing that the black cover bolts to. The electric motor in the centre section and the rear section being the sealed motor control and electronics section. The electrical inputs are a high current circuit and a CAN circuit for controlling the pump. If the CAN protocol on the Jeep and the electrical connections are the same as the Grenadier this pump theoretically could be interchangeable. People are changing the Jeep ones in their garage with what seems to be no reprogramming.

There has been a good deal of information on symptoms other than the noise relating to the noisy steering pumps. I have previously suggested electrical connection issues similar to some faulty Jeeps that could affect pump speed and early in the thread I did suggest possible hydraulic issues particularly in the relief circuit and relief pressure settings. The Jeep version images, and likely no change on the Grenadier version, show these pumps have the most basic spring poppet style relief valve. This type of non-adjustable pressure relief valves is not the best design and it is common to have variances from unit to unit as they depend on a good seat in the pump housing and good spring pressure and generally relive back into the inlet port of the pump. Poppet relief valves are generally for spike protection of the hydraulic system and are noisy, generate considerable heat and fluid turbulence if constantly operating partially open. This could be easily checked at the valve by operating the steering system with normal type driving and not holding on the steering stops. If this valve is continually going over relief the valve and the area around the valve will be considerably hotter than the rest of the pump.

There is a product in the Jeep community that is replacement adjustable steering relief valve or what they call Steering Booster Valve for the steering pump. Once fitted this valve that can increase hydraulic pressure to 2000psi 13.7Mpa to increase steering performance for large tyres and heavy steering loads. This could be beneficial for the pump fitted to a Grenadier not by increasing pressure but by having a better design and being adjustable to the correct and stabilise OEM pressure, keeping the poppet seated for pressure spikes and letting the electronics control the pump and remain as the primary control.







Left Grenadier Electrohydraulic Power Steer Pump EHPS
View attachment 7898315View attachment 7898316
Jeep Gladiator Pump
View attachment 7898328View attachment 7898334

View attachment 7898331

What’s involved in changing the valve, is it a full drain and replace of the fluid or can you quickly swap the valve and top up any lost fluid?

 

[ppearman]

This makes so much sense, ya pretty much have to prove to me it isn't the issue. We may need to pin an Ineos medal on NQ94's chest.

Agreed. If this is correct, US$195.00 + labour (per Agile Off-road) would be well worth to get rid of that whine !!

 

[MileHigh]

NQ94- stop it with your information, insights, and analysis- we’re her to complain!

Agreed. If this is correct, US$195.00 + labour (per Agile Off-road) would be well worth to get rid of that whine !!

And this is what I want to get to- what does it take to fix it and who do I pay to get it done?

Just to clarify, if it is a Gladiator pump- why do we think that would fix it? How is the gladiator pump better? Better doo-dad thingy with holes and stuff?