Advice on a 1988 Fiero hydraulic rack and pinion unit (Page 2/2)
fierogt28 DEC 24, 09:15 PM
Thanks for posting pics of the rack to confirm that this is indeed a prototype 88 P/S rack. That’s why I asked you to post pics to validate the topic.
I mean, really…If someone has the money especially, I believe that seals can be reproduced or made for this rack to get it back into service.

Just like the 88 front bearings, Rodney reproduced 2 designs to make 88 owners have a choice for a bearing replacement option. Sadly they are not the same design and quality as the GM bearing, we know for a fact that if some Fiero enthusiast would have enough money to bring such a project and replicate the 88 GM bearing, it can be done. But like Rodney mention, nobody would want to pay the price for each bearing made. As a Fiero enthusiast myself and trive always for quality, I wouldn’t mind paying 500-600$ a bearing. But many here would say no to that. It all depends on what you want, and how bad you want it.
Some people on this board that own fieros don’t even have a job, and some are questionable millionaires. So, realistically it’s not a good call to make. I would like to take on a project in the future for a few 88 specific parts to reproduce if I would have the money, but have that part built for myself to R&D it. Yes, it would be very pricey, but if you’re interested and want a solution bad, those are the people that will take the project far enough to make a replacement. If it would cost me 1500-2000$ to make a reproduction bearing, I wouldn’t care. I would be interested to see how it lasts and performs. I don’t think the 88 bearing is a complex design, but more a pricey design to make.

So, coming back… those seals probably never made it to production for parts or replacement. But not many were made. They were issued for experimental purposes for the beginning and was canceled. So, that’s the problem. Again, replication of seals is possible, but if you’re willing to dish out the cash to have them custom made. That’s possible especially with today’s technology.
The other issue here to get that rack working is the EHPS unit. That’s another part that could be reproduced if someone could furnish the original GM prototype. Most likely that’s would be a risky task because we are dealing with a very rare part, and a very rare historical part.
After that, I believe an automotive specialist in electrical could wire in to make this EHPS system actually work like the prototype was wired.
I do remember someone on this forum has a 88 Fiero with this prototype set up that managed to escape the factory without it being removed before. If that member could post, maybe we could get pics from under the hood.
And I do believe they there is released wiring diagram out there for this 88 steering system.
Thanks for posting pics for us to see. Much appreciated.

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fierogt28

88 GT, Loaded, 5-speed.
88 GT, 5-speed. Beechwood interior, All original.

[This message has been edited by fierogt28 (edited 12-24-2022).]

fieroguru DEC 24, 10:01 PM
Once he repairs the rack, he can use a mechanical pump or another common electric hydraulic pump to run the rack.
RWDPLZ DEC 24, 10:12 PM
fierosound DEC 25, 11:11 AM

quote
Originally posted by sspeedstreet:

Update: Once I stopped thinking of this as a "power steering" problem and approached it as a hydraulic piston repair, a wealth of options appeared. Yes, regrind and/or rechrome but also several epoxy fillers formulated just for this purpose. After the first of the year I'll pull it apart for a better look.



The Fiero racks are basically longer versions of the Chevette racks.
It may be worth looking at rebuild kits for those.

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My World of Wheels Winners (Click on links below)

3.4L Supercharged 87 GT and Super Duty 4 Indy #163

Daviero JAN 24, 11:16 PM
The C5 Corvette also had similar P/S racks, just narrower. From 10 feet away you'd not see the difference to a Fiero rack when placed side by each.
A member named Rickady88 made some small batches of tie rod adaptors years ago to make the geometry the same as that of the Fiero rack. I installed one on my 88 back then using a mechanical pump on the Northstar. 2 turns lock to lock.

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Daviero - 88 N* 5spdGT

Steven Snyder JAN 28, 05:41 AM
Jeff at Turn One would be a great person to ask about this. He might even be able to dig up some original engineering data... He has connections. At the very least he can probably cross reference the seal sizes, as well as confirm if that's a critical sealing surface.

As for EHPS pumps.. I have been using a Vauxhall Astra EHPS pump (same as Porsche GT3 Cup car pump) with the C4 rack in my Fiero. It works great. No controller or angle sensor needed... Just some 12V power and a wire the field side of the alternator "battery light" circuit. It will probably work fine with that rack.

For a fancier solution get a Mazda3 pump and the NMStec PSC power steering controller. It provides programmable variable assist based on speed or a knob.

[This message has been edited by Steven Snyder (edited 01-28-2023).]

qwikgta JAN 29, 07:36 PM
after you get the rack fixed, just use the Volvo EHPS pump out of a newer Volvo. It only needs power and ground to run, no connection to a speed sensor. In this mode it gives something like 85% of its power and that is more than enough to make the steering easy on a Fiero. Do a google search for "Volvo EPHS" and you will see a lot of data about it.