Power steering Pump Question.

[Ccmano]

I’m working on a power steering issue on my car. I’m finding ZR-1 specific power steering pumps impossible to find at the local parts stores. Rock Auto has one, it’s an aluminum bodied pump not the OEM steel. L98 pumps are plentiful.

I have physically compared the L98 pump and the ZR-1 pumps. They are identical in every dimension. The only difference I can find is the supply hose nipple. Straight on the L98 Pump, slight elbow on the ZR-1 pump. The L98 pump bolts up the the LT5 perfectly. Tried it on the spare engine I have.

My question is this, are these actually identical? The racks they utilize are identical and interchangeable so I would imagine the pump output to be the same. Is anyone aware of any other differences, rotating in the opposite direction or some such?

Thanks
H

[Dynomite]

I have both L98 and LT5 so this is interesting

The L98 Power steering Pulley rides on outside of belt (smooth side) and rotates counter clockwise looking from front.

The LT5 Power steering Pulley rides on inside of belt (grooved side) and rotates clockwise looking from front.

Did not measure diameter of pulleys since they are not interchangeable.
The oil reservoirs are different as L98 is separate and LT5 is behind pulley.

If this sounds strange......I will look again as I just fired up both engines.
I have no modifications regarding Power steering on either Corvette engine (1990 L98 and 1991 LT5)

Corvette Central has Aluminum Body Power Steering pumps (ZR-1) for $145.
https://www.corvettecentral.com/c4-8...f%3fcount%3d18

I did see an advertisement for rebuilt Corvette Power Steering Pumps without the ZR-1 Option.

Rebuilt ZR-1 Power Steering Pumps for $88 (Free Shipping).
https://www.ebay.com/i/253510303250?...SABEgKwMvD_BwE

Search Ebay (ZR-1 Corvette Power Steering Pump) and you will find several used ZR-1 Power Steering Pumps.

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[secondchance]

Might be wothwhile to talk to a tech with a turn One.
https://www.turnone-steering.com/

I had my rack rebuilt these guys and they did an outstanding job.

[Paul Workman]

[Ccmano]

Thanks Cliff, looks like it does rotate in the opposite direction. Answers that question.
H

[gbrtng]

NAPA used to stock rebuilts ... apparently used on other GM vehicles because there was one at the local store in Naperville. NAPA did not have a way to cross reference to the other applications however. Probably a Geo or Malibu ...

[Ccmano]

So here’s an update. Internet/Ebay sellers were all out of stock, even though they were running current ads. I suspect many used the same source. None of the local parts outlets have stock including NAPA.

This part is IMPORTANT! The only pump currently available is the one sold by RockAuto and others manufactured by the LARES company in Minnesota. You can buy them new or rebuilt. THEY DONT FIT! The reason the don’t fit is because the two lateral mounting holes (of three) are not threaded and are too large on their pumps. I ordered one from RockAuto, opened the package and found the holes unthreaded and too large. I called LARES and the nice folks there told me it was a mistake, to send it back and another would be sent. I did that, got the pump and it was identical to the first. Called the nice folks at LARES back (they really are nice), this time they told me that based on the GM specs they use the holes are not threaded. WRONG! I’ve done a bunch of these, all three holes are threaded. That second pump is going back too. No new pump coming.

So at present if you need a PS pump you will need to either send it to TurnOne or LARES and have it rebuilt or rebuild it yourself. Mine was a bad bearing so I’m rebuilding it myself. A complete kit is less then $20.

As previously noted these pumps are unique in that the rotate clockwise (when viewed from the front) whereas L98 pumps rotate counterclockwise. Looks like we may be adding another part to the scarcity list.
H

[gbrtng]

Is there any possibility of using thread inserts?

[Ccmano]

Originally Posted by gbrtng

Is there any possibility of using thread inserts?

I suppose, probably have to redrill, thread and use a helicoil or such of appropriate size. Could affect warranty though.
H


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[A26B]

Originally Posted by Ccmano

......................................So at present if you need a PS pump you will need to either send it to TurnOne or LARES and have it rebuilt or rebuild it yourself. Mine was a bad bearing so I’m rebuilding it myself. A complete kit is less then $20........................................
H

Great job doing all the research to be able to solve this parts "NLA" delimma. Do you have a source & PN for the "complete rebuild kit?

Thanks Hans!