Disco-1 Electric-hydraulic power steering conversion DONE!

ERover82

Well-known member
Nov 26, 2011
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Darien Gap
RRC/P38 brakes are similar in design but very different in practice. The parts used are just more effective and more reliable.

Always thought the D1 lamps were really good, better than Defenders with their 7” round lamps. Increasing wattage to compensate for a smaller, less efficient lamp doesn’t really make sense - you could just put the same bulb in the better lamp. Additionally, the glass is much more durable than the relatively soft plastic lenses that oxidize over time.

Never had a problem with D1/2 steering either though. In good working order, and with reasonably sized tires, I never found myself wishing for more power or less noise. They seemed to work as well as any other truck.
 
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DiscoClay

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Mar 18, 2021
548
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Chapel Hill, North Carolina, USA
RRC/P38 brakes are similar in design but very different in practice. The parts used are just more effective and more reliable.
I get the impression you don't approve of my mods :) I'll line item your points and my comments:

I'm not an expert on Classic brakes or P38 brakes. I do know NAS disco brakes are great for stopping golf carts while being complete garbage for stopping 5,000 lbs of wagon from 75mph.

I also really like having more boost rather than less...and dialing it back from there.
Always thought the D1 lamps were really good, better than Defenders with their 7” round lamps.
I have no experience comparing them, but do have plenty of experience with the smaller Hella OE headlamps (not to be confused with the fogs of similar size) and I know they are very capable of bouncing lots of photons.
Increasing wattage to compensate for a smaller, less efficient lamp doesn’t really make sense
it makes complete sense when desiring to install smaller, WAAAY MORE SHINY reflectors in place of old non-shiny aluminum film reflectors. :)
- you could just put the same bulb in the better lamp.
The Hella lamp is vastly better than a 30 year old (worn out) sputtered aluminum plastic reflector.
Additionally, the glass is much more durable than the relatively soft plastic lenses that oxidize over time.
100% disagree with this. I've replaced ~6 glass lamps in ~15years.

Deserts and gravel have proven (to me) glass breaks and pits...a lot; polycarbonate doesn't [*relatively].

Removing a few years of haze from PC is a 10 minute visit with a bottle of Maguire's polish, a buffer and a couple ice cold beers :) Removing craters and pits from glass is simply not practical.
Never had a problem with D1/2 steering either though.
I have. More than once.

Moreover, i am interested in bringing my remaining disco into the modern era with some updates to drivability.

As I said waaaay up there^ the steering is on another level; it simply and completely outclasses the stock steering; no comparison.
In good working order, and with reasonably sized tires, I never found myself wishing for more power or less noise.
I guess you have had better luck than me, or a higher tolerance for pain. :)

I have ensured good working order and avoided mudbog 40"ers and yet I find both steering and brakes dangerously lacking.:)

I am making the headlight mods for a combination of reasons: scarce NOS lamps/reflectors, ridiculous prices for them, desire to have non-glass lenses, more pronounced horizontal cutoff, brighter output, and because having the stock fiberglass reflectors re-sputtered is prohibitively expensive.
They seemed to work as well as any other truck.
Lets agree to disagree. :)
 
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nmstec

Member
Apr 18, 2023
5
7
Vancouver
Talk to Mark about that ebooster. If you an get the VIN it is probably doable.

I really am torn: I really like the hydraboost.. I have it on an old Ford dually and it is incredibly strong and reliable. No vacuum issues and it fairly compact. The main issues to put to bed are:
  1. Will the e-pump deliver enough volume for both the steering and the brakes?
  2. If I use that single pump it will surely have to get cranked up to max/near max
  3. I will loose the ability to manually modulate the steering boost (because it will also effect the brake boost)

That said.. the ebooster is my first choice. So long as the battery has juice the power brakes will work. Plus; i *really* like the idea of being able to dial in the boost, just like with the steering.
Teeeeechnically if we have that much overhead on the pump, a pressure sensor may do the trick. Tie pressure sensor into my controller, and we can map out a "boost" map, that if pressure drops beyond expected level during brake application, to bump up the pump to target that pressure.
 
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p m

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Apr 19, 2004
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Always thought the D1 lamps were really good, better than Defenders with their 7” round lamps. Increasing wattage to compensate for a smaller, less efficient lamp doesn’t really make sense - you could just put the same bulb in the better lamp. Additionally, the glass is much more durable than the relatively soft plastic lenses that oxidize over time.
FWIW, FYI - higher wattage bulbs are guaranteed to crack glass lenses on Hella housings (unless you use 55w low / 100w high and never use high beams).
I am running 80/100 bulbs in Hella E-code H4 housings, but I know that now they are a wearable item.
 
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DiscoClay

Well-known member
Mar 18, 2021
548
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Chapel Hill, North Carolina, USA
Teeeeechnically if we have that much overhead on the pump, a pressure sensor may do the trick. Tie pressure sensor into my controller, and we can map out a "boost" map, that if pressure drops beyond expected level during brake application, to bump up the pump to target that pressure.
Great idea :) I shoulda pinged you on that. Either way, a FrankenBrake is in the future.
 

DiscoClay

Well-known member
Mar 18, 2021
548
119
Chapel Hill, North Carolina, USA
FWIW, FYI - higher wattage bulbs are guaranteed to crack glass lenses on Hella housings (unless you use 55w low / 100w high and never use high beams).
I am running 80/100 bulbs in Hella E-code H4 housings, but I know that now they are a wearable item.

What are you using them for? Trail lights?

Have you considered using heatsinks on the back of the reflector?

I've been thinking about heat buildup and condensation remediation for my design.. I am currently leaning toward a small airfilter/port with an hv (1u server size) fan to cycle air through it. *The wagon isn't rigged for fjordding.

Any constructive thoughts are welcome :)
 

p m

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What are you using them for? Trail lights?

Have you considered using heatsinks on the back of the reflector?

I've been thinking about heat buildup and condensation remediation for my design.. I am currently leaning toward a small airfilter/port with an hv (1u server size) fan to cycle air through it. *The wagon isn't rigged for fjordding.

Any constructive thoughts are welcome :)
I am using headlights .... as headlights.
I don't think it is worth investing in modifications in Hella housings. I've recently upgraded my daughter's Classic headlights with Holley Retrobrights - while the light distribution is noticeably worse than E-code Hellas with halogens, the total amount of light is comparable with 3000k bulbs, and much more with 5700K bulbs.
BTW, the reflectors in Holley Retrobright housings double as a massive heat sink. They are not flange-compatible with 9003/H4 bulbs, but it looks like this ship has sailed.
 
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DiscoClay

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Mar 18, 2021
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Chapel Hill, North Carolina, USA
I am using headlights .... as headlights.
I don't think it is worth investing in modifications in Hella housings. I've recently upgraded my daughter's Classic headlights with Holley Retrobrights - while the light distribution is noticeably worse than E-code Hellas with halogens, the total amount of light is comparable with 3000k bulbs, and much more with 5700K bulbs.
BTW, the reflectors in Holley Retrobright housings double as a massive heat sink. They are not flange-compatible with 9003/H4 bulbs, but it looks like this ship has sailed.

Ah, you are referring to the 7" Hellas; I was wondering what you'd be using the 5.75" rounds for.

A little airflow on those holleys and you should be gtg. Too bad they aren't as tight as the E4's
 

DiscoClay

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Mar 18, 2021
548
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Chapel Hill, North Carolina, USA
Neat. How much current is drawn when turning?
Good question. I don't know :p

I have not observed any electrical system problems or concerns.

Given I run the pump down in that 20% range, a complete guess for loading could be 60 amps * 0.2 = 12 amps (*14v ~= 168w)
Maybe Mark has better theoretical values for this.

I need one of those clamp-on load/current meters. I'll post here when I unlock that "new tool" :)
 

nmstec

Member
Apr 18, 2023
5
7
Vancouver
Neat. How much current is drawn when turning?
Sorry, seems I missed this message. So the OEM wiring diagrams have 2x 50a parallel fuses so I expect no more than 80amps at full power, full load.
The mazda pumps I have that are rated for 500psi lower bypass, and 0.6gpm less, have 80amp fuse, and run on a drift care absolutely brilliantly at 100% load. Drift cars are about as high load as it gets due to extended control arms, and living at lock to lock.

I'd presume the Jeep/Charger pumps would need quite a bit less, as theres no real point running them at 100%.
 
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DiscoClay

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Mar 18, 2021
548
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Chapel Hill, North Carolina, USA
Six Month Update

Rockin! Have YOU converted your yet? Get on it!

The short belt is holding up well.. given my level of laziness, and lack of a mill (at present), I have not made the standoff/bracket to attach the power steering idler pulley. Also, that big open area next to the distributor is just nice to look at... although maaaaybe that M122 blower snout would fit in there....
 

StangGT5

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Feb 4, 2019
330
158
Atlanta, GA
I have to say, this is an impressive amount of work and good knowledge for the community. I'll be coyote swapping a car in the near future, and a standalone pump would make that easier.

With that said, the pump on my RRC with 35" tires does fine, and isn't audible above the rest of the truck. With as leaky as Rover steering boxes are I'd be worried more pressure would just exacerbate the problem. I can't speak to D1 steering, but I have always felt the Discovery 2 steering was as good as solid axle vehicles get.

Still, maybe when the pump goes out on the RRC (knock on wood that isn't anytime soon), this would be worth looking into. I have a giant air compressor where you mounted the pump, so I'd have to get even more creative.
 
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DiscoClay

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Mar 18, 2021
548
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Chapel Hill, North Carolina, USA
Yeah, maybe I've just had bad luck with pumps. That said, I really like being able to adjust the boost pressure.

Regarding the CRAPPY steering box bolted to the D1, this pump is a Godsend: it lets you reduce the pressure.

Recall that the most [volume] pressure is expended at the slowest speeds.. e.g.: the effort to turn the wheel is greatest when the truck is parked and the effort is the least when the truck is motoring down the highway.

Also recall the pump makes the least amount of [volume] pressure at idle.. and the most at high RPM.. which is the exact opposite of what is required.

With the electric pump (https://www.nmstec.ca/2023/01/31/support-for-a-new-and-most-powerful-ehpas-weve-seen-yet/) and Mark's controller (https://www.nmstec.ca/product/psc/?currency=USD), you are able to provide the minimum amount of [volume] pressure desired/needed to turn your wheels... Meaning: this conversion can help your steering box last longer! :)))

There are other locations, but it is certainly the no-brainer position :) If you nix your ABS pump then you may be able to stow it there?
 
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DiscoClay

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Mar 18, 2021
548
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Chapel Hill, North Carolina, USA
Update:
Installed: New, shorter multi V-belt (7PK1664, GoodYearBelts.com: 1070655) installed. It is a little too tight.. not enough to kill bearings, but enough that the tensioner does not have enough travel to allow it to slip on; I pulled the top alternator bolt and dropped the alt just enough to install it. The tension really wasn't bad so I'll go with it for now.

It appears nobody makes a 7PK18774 (like a goodyear 1070690, aka: 65.90 inches) that would be perfect.
 

DiscoClay

Well-known member
Mar 18, 2021
548
119
Chapel Hill, North Carolina, USA

DiscoClay

Well-known member
Mar 18, 2021
548
119
Chapel Hill, North Carolina, USA
I finally got the power steering pump hole filled in with a second alternator :p I mentioned it in another thread but I figure I should post pics here. These are prior to buttoning it all up (hose clamps, wires, etc).

This restores the OEM serpentine belt to the wagon.

All is still working great. This is a great update for anyone who parks in the city.. :)20240915_151250.jpg20240915_151243.jpg20240915_151234.jpg
 

DiscoClay

Well-known member
Mar 18, 2021
548
119
Chapel Hill, North Carolina, USA
Speaking of OEM stock "multi-groove" serpentine belts for the NAS 14CUX Disco1... Here is some cross-reference belt part numbers if anyone wants an archive of the options as of 2024 (sorry, it's an image, not searchable:

Stock Serpentine Belt Cross Reference part numbers 7PK2248 list.jpg
 
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