I'm hoping someone here can give me advice on a 1988 Fiero hydraulic rack and pinion unit. I found this one in a junked car in Michigan. My question is about corrosion on the rack shaft. Both ends under the boots (bellows) have surface rust. Is that area critical to sealing the unit? Sadly, no info seems to be around any more for these. Any insight into how critical the finish needs to be at this location?

[This message has been edited by sspeedstreet (edited 12-13-2022).]

No Fiero has PS. 88 was going to have PS but was Electric unit and deleted from final version.
Someone Mod'ed the car to have PS and you have to guess what PS rack was used.

Rust near the ends on the rack when can see car steered straight is maybe ok.
Depends exactly where the rust is and if it is in the "working zone" where rust hits hydro seals then the seals won't last long.
Even if rust removed first, any pitting or other damage can cause seal problems too.

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Could you post more pictures of the rack?

Not visible from this angle, but the bracket that supported the electro-hydraulic pump still has the rubber bushing in it. Also, I noticed the hydraulic fittings to the ram are clocked to the horizontal. I wish I'd thought of that when I installed a C5 rack in my '88. In the stock Corvette vertical position they interfere with the spare tire bulkhead. I ended up using banjo fittings to get clearance.

That looks like an EHPS rack for the 88s. You might want to go back to that car to see what else if anything is left.

Based on the location of the hydraulic lines, the corrosion on the shaft is going to cause a hydraulic leak at the seal.

[This message has been edited by fieroguru (edited 12-14-2022).]

quote Originally posted by fieroguru: You might want to go back to that car to see what else if anything is left.

I wish, but all the seller had was the front suspension out of the car.

Due to the rarity of this rack, I think it can be repaired.

The corrosion may be a problem for seals, but the shaft could be ground and polished by a competent machine/finish shop, an engine shop with a crank grinder could accomplish this as well. depending on the depths of corrosion the seal has the possibility to work, if it must be ground further than a few thousands of an inch, there my be a undersize seal available. But you will have to tear it all down to pull the rack gear out to see.

There are steering rack rebuilders that are US based still out there, but expect to pay dearly. Like Turn One (https://turnonesteering.com/rebuilding-services/rack-and-pinion-rebuilding/) , but for these older and rarer cars there really are few options.

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.

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).]

Once he repairs the rack, he can use a mechanical pump or another common electric hydraulic pump to run the rack.

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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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

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).]

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.