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Post by thomashb on Jul 18, 2022 11:13:17 GMT
I’ve done some searching here and on other forums for information about fitting electronic power steering solutions to the V8 but I am keen to know if anyone has made any efforts in this space since the last substantive discussion on the topic here in approximately 2018.
I’ve read that the Citroen Saxo pump may be suitable, but apparently produces more than 1000psi. Similar, universal electric pumps seem to produce similar pressures.
According to the Workshop Manual the P5B V8 power steering pump operates between 100psi (steering wheel released, engine idling) to 400psi at idle, full lock and 650-750psi at 1000rpm, full lock.
As the Workshop Manual Power Steering fault finding chart refers to cracked steering boxes as being caused by high-pressure from faulty relief valves, clearly excess pressure is problematic.
Any advice in this space?
Also curious if anyone has installed an EPAS column (either Universal kit or one from a wrecked Prius) under/behind their dash. There doesn’t look like enough room in the engine bay with the exhaust header to one side and the wheel arch to the other.
Grateful for any advice.
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Post by enigmas on Jul 18, 2022 11:44:11 GMT
Try not to confuse an electric power steering pump (that creates hydraulic pressure for an hydraulic power steering system) with an electric power steering system.
If you were to fit EPS to a P5 then fit the best manual steering box from one of the 3 litre cars.
Another option is to fit an EPS rack and pinion system (note the rack is directly powered by an electric motor) to a P5 but this is fraught with complexity for a number of reasons, too many to list here.
or
Fit the Volvo power steering box,
or
Just have the hydrosteer properly rebuilt by someone who "really" knows what they're doing. The pump output pressure isn't an issue unless you want it to be one.
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Post by thomashb on Jul 18, 2022 11:49:25 GMT
Understand the difference between the two, thanks Vince!
Just trying to think of two different ways of tackling it.
I **think** my steering box is fine and therefore neither needs rebuilding nor replacing with a Volvo unit, but I have a fairly significant leak from the pipes near the pump and reservoir.
This has happened just as I’ve toying with the idea of repowering the car and so my mind was wandering to either an electric pump solution or a column EPAS so I can ditch the belt driven unit.
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Post by johnwp5bcoupe on Jul 18, 2022 14:02:03 GMT
Understand the difference between the two, thanks Vince! Just trying to think of two different ways of tackling it. I **think** my steering box is fine and therefore neither needs rebuilding nor replacing with a Volvo unit, but I have a fairly significant leak from the pipes near the pump and reservoir. This has happened just as I’ve toying with the idea of repowering the car and so my mind was wandering to either an electric pump solution or a column EPAS so I can ditch the belt driven unit. The PS pump is a very reliable unit I wouldn't bother changing it, when you say leak from pipes do you mean the high pressure side or the low pressure side? unions?
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Post by enigmas on Jul 19, 2022 4:40:25 GMT
I've been doing a bit of research re: EPS myself and the notion of a front mounted, directly powered rack and pinion steering system (not a column powered unit) makes a lot of sense. If you have a technical interest in these systems and understand the geometry associated with steering systems then it's well worth viewing this video. As an aside, I have a spare ZA MG Magnette front mounted manual (rack and pinion) steering assembly at home, but have not as yet measured the positions of the inner swivels to see if they are appropriately positioned to align with the P5s lower front suspension arm swivels. This is the standard rack fitted to my ZB MG Magnette and is mounted via small rubber bushes. The earlier ZA steering rack is a solid mounted unit but identical. If this unit is suitable it could be powered by a Toyota Prius EPS unit mounted on the Rover steering column under the dash. The P5 steering arms would also need to be heated and bent outwards towards the wheel rims to correct the achermann.
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Post by vincentacres on Jul 19, 2022 10:30:17 GMT
I have done a Volvo steering box conversion some years ago now and can vouch for the improvement in stability and confidence at speed. However over time sourcing these boxes will become harder.
I also have a P5 manual steering box and have toyed with the idea of electric steering. I considered the EZ power steering system which has been fitted to various Aston's, Bentley's etc. It seemed to me though that as this is a column mounted, columns drive system and the P5B column shaft is enclosed that the engineering would not be straightforward.
Interested to see if you arrive at a viable alternative solution Vince.
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Post by enigmas on Jul 19, 2022 11:39:55 GMT
Hi Owen, you might find these 2 videos of interest. Both the cars below have utilized the Easysteer units, but the Toyota Prius can be had for a fraction of the price and is easily adapted. Wiring a Prius unit is literally straight forward with only 3 wires required, 2 heavy gauge wires one for power (use a 20Amp fuse), one for a Ground/Earth and a light gauge wire to activate the system from the ignition switch. This is the Prius module wiring. There is no shortage of info on the internet with regard to these EPS systems, especially Youtube. This video ((below) particularly interested me. How's your French? The video imagery reveals most of the pertinent details of fitting an EPS to a classic car's original steering system without understanding what is spoken. The only part of this modification that concerns me is the "really crappy weld" on one of the steering couplings. This guy cannot put down a decent weld in my view and I wouldn't pass it, but that's my only complaint with the modification. This is the crappy weld with suspect penetration shown. (It was passed over very quickly in the video). This is not an issue for someone who can weld proficently.
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Post by vincentacres on Jul 19, 2022 12:05:19 GMT
Hi Vince,
Thanks for the videos - they are indeed a compelling case. I'm convinced electric steering is the way to go in so far as it provides a number of benefits and removes a number of potential problems plus negates another system the engine has to drive in an inefficient manner with another belt drive.
What I would like to see is EZ to do a P5/P5B and then I believe once the install us proven owners will open their cheque books so to speak ..
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Post by enigmas on Jul 19, 2022 12:17:43 GMT
I totally agree Owen, but I'd still like a R&P system in a P5 for precise steering.
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Post by thomashb on Jul 19, 2022 12:31:14 GMT
Given the P5B power steering boxes are supposed to function effectively in the event of pump failure, is there any reason you couldn’t run the EPAS column into a power steering box with the power steering pump hoses disconnected?
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Post by enigmas on Jul 19, 2022 23:42:21 GMT
Given the P5B power steering boxes are supposed to function effectively in the event of pump failure, is there any reason you couldn’t run the EPAS column into a power steering box with the power steering pump hoses disconnected? An EPS system would provide the most precise steering in a P5 if a Rack and Pinion unit either manual or electrically driven were used. The hydrosteer PS box is meant to function under hydraulic pressure. If no pump pressure is available it functions manually via a worm and peg. It is not a mechanically precise system and there's always freeplay at centre steer. Certain P5 manual steering boxes are more precise with steering quality but require more effort when stationary or moving at slow speeds. That's where an add-on EPS system such as the one in the P4 shines. If you want razor sharp precise steering then fit a rack and pinion system, but you'll require some engineering expertise as there are aspects of steering geometry to consider.
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Post by Jens Munk on Jul 20, 2022 22:40:24 GMT
Any links to rack-pinion conversion of a P5B? Preferably LHD.
I believe my Hydrosteer is as good as it gets, but that still means it is not very precise.
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Post by thomashb on Jul 20, 2022 23:14:46 GMT
Vince was back and forth in another thread with an NZ based member here about Toyota Hiace racks being approximately the right length, with some modification required to suit the ball joints and some bending of the steering arms to solve for the correct Ackermann angle. I don’t think anyone actually tried it though! You can get new Toyota racks without hydraulic power assist (as they’re designed with an EPAS column in mind) for approx AU$500 for Prius, Corolla, Kluger etc and these would all be available in LHD of course. Possibly the Kluger, RAV4 and the Tarago will be closer in front track width than a Corolla or Prius. Unhelpful for you, Jens, but Repco in Australia sell a complete rack with electronic power assist built in for AU$2200, available here: www.repco.com.au/en/parts-service/steering-suspension/power-steering/repco-new-full-electric-steering-rack-rnsr320031/p/A5558829
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Post by thomashb on Jul 24, 2022 3:37:18 GMT
Given the P5B power steering boxes are supposed to function effectively in the event of pump failure, is there any reason you couldn’t run the EPAS column into a power steering box with the power steering pump hoses disconnected? An EPS system would provide the most precise steering in a P5 if a Rack and Pinion unit either manual or electrically driven were used. The hydrosteer PS box is meant to function under hydraulic pressure. If no pump pressure is available it functions manually via a worm and peg. It is not a mechanically precise system and there's always freeplay at centre steer. Certain P5 manual steering boxes are more precise with steering quality but require more effort when stationary or moving at slow speeds. That's where an add-on EPS system such as the one in the P4 shines. If you want razor sharp precise steering then fit a rack and pinion system, but you'll require some engineering expertise as there are aspects of steering geometry to consider. Just back to this Vince, do you know whether operating the hydrosteer as a manual box, without the hydraulic PAS pump connected, would do any damage? The R&D to find and fit a rack and pinion steering solution is probably beyond my means, but I can arrange the fitting of an EPAS column quickly and easily enough. It might be vague and imprecise compared to a rack and pinion setup, but that is the status quo as it stands anyway.
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Post by enigmas on Jul 24, 2022 5:44:31 GMT
Thomas, I wouldn't use the hydrosteer box in manual mode permanently. It was not designed to be used like that. Manual use is a failsafe backup if hydraulic pressure is lost for some reason or other. Mike Hancock used his saloon "Winston" like that for years, but truly I wouldn't advise it. The rebuilt hydrosteer and pump did cost several thousand dollars to properly repair. If you want to pursue the EPS option, then it would be best to find and fit a manual P5 3 litre steering box and then fit the EPAS system to the steering column as per the Rover P4 in the video above. PS. Interestingly, yesterday if I'd wanted to, I could have purchased a column mounted EPS unit and module from a 2007 Toyota Prius for $116 AUD from a local motor wrecker. I would have had to remove the items from the car though. The components are available at very reasonable prices if you do the research. PPS. Adding 3° positive caster to the front suspension (top wishbones) improves the quality of the steering at speed significantly. The car will also then self centre after a turn. Here: "Front Wishbones Caster Alterations", three quarters of the way down the page. You will require a proficient welder fabricator and a simple jig like the one shown if you want to do this modification to the top wishbones. roverp5.proboards.com/thread/12128/mikes-loon-saloon?page=7
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Post by thomashb on Jul 24, 2022 8:27:25 GMT
Hrrrmm,....
I guess I may be overthinking an overengineered solution to my leaking reservoir and (maybe) pump.
My steering box is fine. The reservoir-to-pump hose was sodden, but of a wrong specification (heater hose). I'll make a trip to Pirtek when I get a chance for a length of low pressure 5/8" ID oil transfer hose.
Wadhams is closed til mid August though, so it's a long wait for a reservoir seal kit to be sent out.
Hard to know if the pump is leaking or just sodden with ATF from the reservoir and hose though, so maybe one thing at a time.
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Post by Mike’S-a-loon on Jul 24, 2022 20:11:33 GMT
Hancock, Vince, Hancock...
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Post by johnwp5bcoupe on Jul 25, 2022 8:43:45 GMT
Hrrrmm,.... I guess I may be overthinking an overengineered solution to my leaking reservoir and (maybe) pump. My steering box is fine. The reservoir-to-pump hose was sodden, but of a wrong specification (heater hose). I'll make a trip to Pirtek when I get a chance for a length of low pressure 5/8" ID oil transfer hose. Wadhams is closed til mid August though, so it's a long wait for a reservoir seal kit to be sent out. Hard to know if the pump is leaking or just sodden with ATF from the reservoir and hose though, so maybe one thing at a time. Change the low pressure delivery hose Thomas for a start, and make sure the rubber washer is in place on the pump LP connector, worry about the reservoir later!
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Post by thomashb on Jul 25, 2022 21:18:33 GMT
Change the low pressure delivery hose Thomas for a start, and make sure the rubber washer is in place on the pump LP connector, worry about the reservoir later! Is the washer a particular specification for the rubber washer? With Wadhams closed until mid August, it is probably easier to source one locally. I’m away from home this week but from memory the low pressure Reservoir-to-Pump hose fitting was a jubilee clip holding the hose over a flared steel inlet, so no washer fitted.
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Post by enigmas on Aug 4, 2022 8:03:22 GMT
Electric Power Steering unit & Module.I went to the motor wreckers today and unbolted an Electric Power Steering assembly from a Toyota Corolla. It's a "Pick A Part" type of place with hundreds of cars on a very extensive property. Cars are kept for a month or two and then crushed. Amazing how many late model cars are in the yard. The initial aim was to remove the system from a Toyota Prius but I couldn't locate the one car in the yard and so defaulted to a Toyota Corolla as it also had an EPS. Here are the components that I removed from the car. I don't really have any current plans to adapt the EPS to my P5 Coupe. If I did, it would be to power a manual rack and pinion steering system, but this would involve quite a lot of engineering. I still have a complete hydraulic Volvo PS system with adaptor plate for my Coupe in a stash. This is a much easier option. I believe the one modification that stands out to improve the P5s (primarily P5Bs) steering stability the most, is to add a minimum 3° postive caster to the front suspension. This definitely eradicates the tendency to wander at speed. Adding another 2° - 3° would obviously give the car strong straight line stability. This much caster though, definitely requires power steering, whether hydraulic or electric. You would also notice that the front wheels would lean into a turn (it slightly lifts the front end when turning), something the front wheels of all modern cars do. The total price that I paid for the EPS system was $140 AUD.
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Post by enigmas on Aug 6, 2022 9:15:15 GMT
Wiring up the various EPS "Toyota" Modules. FYI For those interested in the EPS option, I'll be updating this page occasionally as I come across any relevant tech literature. Below are several simplified electrical tech sheets for wiring-up the various Toyota EPS modules. Note. Toyota EPS modules have a built-in default option (not all other makes do) for power steering assistance when specific sensors fail or are not connected to the module. Obviously there's no speed sensor, engine rpm or ABS input to the module when it is custom fitted to a classic car. Of course, if you're an electronics guru you could possible cobble-up and fit these sensors. If you are this person, you're most welcome to add the tech detail to this blog. Note: If during modifications to your specific car you decide to fit an electronic speedo then this could provide the speed signal to the EPS module. Toyota Cars Generic Wiring Colours.www.toyotanation.com/threads/wire-color-question.153840/?PC=EMMX01Use the following as a guide to wire up the Toyota Corolla EPS module. NOTE the Following:Toyota uses several specific wire colours that are the same on all years. These are: * White wire, black tracer for ground (-) * Blue - hot (+) when ignition switch is on. * White or White with red tracer - hot (+) at all times. These colour wires are easily identified on the Toyota Corolla EPS module shown in the above posts. I bench wired the Toyota Corolla EPS today and it worked perfectly with the 3 wires connected. The default setting is equivalent to most modern hydraulic power steering systems. The torque sensor is built within the geared EPS unit (not the module) so if increased steering load is sensed (when stationery or moving slowly) the EPS module adjusts the power assistance required. Find below 3 wiring tech sheets. Yellow Highlighted sections indicates the required connections. 2009 Toyota Prius 2007 Toyota Yaris The link below is very comprehensive with lots of useful tech and pictures of various manufacturers EPS units. www.therangerstation.com/tech/toyota-electric-power-steering-eps-conversion/?PC=EMMX01
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boz
Rover Rookie
Posts: 12
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Post by boz on Aug 7, 2022 11:22:19 GMT
Great topic, your correct Vince the Wolseley does have the same hydrosteer unit, but it would be quite a challenge to convert it. I don't think I have a leak on my steering but I think I would have my unit rebuilt if it did play up in the future. The work involved would be too difficult for my skill set, David
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Post by thomashb on Feb 25, 2023 8:09:40 GMT
Just back to this thread and the original question I posed about pressure in the PAS system.
My power steering pump bearing is suddenly quite wobbly and noisy and is — I think — the cause of some stalling around corners.
Obviously I can purchase the Wadhams rebuild kit and take it to a power steering place to have it serviced.
What I want to know from people who understand these systems better than me is whether an electric powere hydraulic power steering pump (eg from a Vauxhall or Holden Astra) would provide too much pressure (1200psi) or if this doesn’t matter since the pressure relief valve relieves that excess pressure?
Presumably an electric powered hydraulic pump provides that pressure at all times.
Whereas a pulley powered pump provides different pressures at different RPM?
But if the pressure of holding the steering at full lock can provide too much pressure to the steering box quadseal at idle speeds, presumably the pressure issue is unrelated to engine RPM since most lengthy full-lock scenarios occur at low speeds and low RPM.
Thanks, Tom
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Post by enigmas on Feb 26, 2023 10:52:54 GMT
Just back to this thread and the original question I posed about pressure in the PAS system. My power steering pump bearing is suddenly quite wobbly and noisy and is — I think — the cause of some stalling around corners. Obviously I can purchase the Wadhams rebuild kit and take it to a power steering place to have it serviced. What I want to know from people who understand these systems better than me is whether an electric powere hydraulic power steering pump (eg from a Vauxhall or Holden Astra) would provide too much pressure (1200psi) or if this doesn’t matter since the pressure relief valve relieves that excess pressure? Presumably an electric powered hydraulic pump provides that pressure at all times. Whereas a pulley powered pump provides different pressures at different RPM? But if the pressure of holding the steering at full lock can provide too much pressure to the steering box quadseal at idle speeds, presumably the pressure issue is unrelated to engine RPM since most lengthy full-lock scenarios occur at low speeds and low RPM. Thanks, Tom Tom are you sure it's a pump bearing and not the pulley that is the problem. The pump pulley's internal driving slot/channel can on occasion fret against the pump driving shaft key so that the machined slot becomes oversized. The pulley then rattles around on the shaft. (I have 2 examples that illustrate this situation.) Second Query. Pressure relief valves are designed to relieve pressure at a specific psi. This is usually based upon the safe maximum working pressure required by the power steering system design. Unless you really know what your doing with hydraulic pumps then it's best to leave these components alone. Retrofitting alternative pumps is an option if you know what you're doing and understand high pressure hydraulic systems, otherwise stick with what the original manufacturer designed.
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Post by johnwp5bcoupe on Feb 27, 2023 12:09:05 GMT
I agree with Vince you are trying to reinvent the wheel! The PS Pump is very reliable and adequate for the job, the bearings seldom give any trouble there is loads of info on site, the box works very well at low pressures so there is no point in supplying it with a constant high pressure. The quad seal will leak at no pressure when the seal and both the recess and shaft are worn due to running in dirt.
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