NV7 Power Steering Pump EVO Component Swap Writeup

[Galaxie500XL]

The NV7 variable assist steering was used only a couple of years on LQ1 Cutlass and GTP Grand Prix cars. As a result, a rebuilt NV7 pump is very difficult to find, and expensive. GM no longer offers the pump, and most of the NV7 pumps I've found in the junkyard are just as bad as the pump you're replacing. However, it is possible to use a standard pump, and simply swap the EVO component to the new pump. Below is a description on how this is done.

 

One important thing...I've encountered TWO different designs of EVO component on NV7 pumps. One style has two "dimples" in the top of the EVO component, and the other is smooth on the top. They are made differently, and this disassembly description is for the "plain" topped one. I tried dissambling the "dimple" type, and haven't figured out yet how to take it apart.

 

First off, make sure you've got a 30mm 6-point socket. Please resist the temptation to use an adjustable wrench to remove the unit...trust me, you'll make a mess.

 

 

1. Remove original NV7 pump from car.

 

2. Remove the fluid tank from the old NV7 pump. SAVE the tank, a standard LQ1 tank is DIFFERENT from the tank used on NV7 pumps, you'll have to reuse your old tank. You MUST remove the tank before continuing, there's not enough clearance between the tank and the nut that holds the adapter on the pump to get the socket in there. If you try, you WILL crack your pump fluid tank...much better to simply get it out of the way, and not chance breaking something you need later in the process.

 

3. I bolted the pump sans tank back on the engine. Safer than using a vise, and you'll need to put a fair bit of effort to remove the EVO unit.

 

4. Use snap ring pliers to remove the weird snap ring off the top of the EVO unit. The ring has a tab on it that prevents the electrical connector from rotating. Keep that in mind when you go to reinstall the snap ring on reassembly.

 

5. Once the snap ring is removed, you'll see an "E" clip underneath. Remove the clip, noting the clip is deliberately bent to hold things properly in place. Note the direction of the bend, so you put it back the same way on reassembly.

 

6. Once the "E" clip is removed, the coil assembly can be lifted off of the EVO compnent.

 

7. With the coil assembly removed, you'll notice that there are TWO hex heads exposed, the large 30mm hex that holds the EVO component adapter on the pump, and a smaller hex on top of it, forming the "hat" covering the EVO pintle. Remove the "hat", by unscrewing it from the EVO adapter, exposing the EVO pintle. You really DO want to take the EVO apart, so there's no chance of damaging it when struggling to remove and reinstall the EVO adapter to the pump.

 

8. With the EVO "hat" removed, you'll see the EVO pintle. It looks a lot like a needle used to fill footballs. Note at the bottom of the pintle, there's a silver washer...make sure not to lose it. Also, you'll notice a groove in the top of the silver top of the pintle. On mine, the groove was parallel with the pulley. I don't know if that's important or not...note the position of yours. I put mine back exactly the same way, just in case.

 

9. With the EVO component disassembled, use the 30mm socket to remove the EVO component adapter from the old power steering pump. Mine was EXTREMEMELY tight...be careful not to rock the socket, you'll round the nut in a heartbeat!

 

10. Be careful when removing the adapter...the pressure regulator (with a strong spring) is directly under the adapter, and may fly out...The EVO component adaptor consists of two parts, the cast iron adapter, and the threaded insert that holds everything in.

 

11. Lay everything aside, and remove the old pump from the engine.

 

12. Remove the tank from the NEW pump, and bolt it to the engine (or use a vise).

 

13. Remove the pressure outlet fitting from the new pump. Again, watch out, the pressure regulator piston "lives" under the fitting, and may try to fly out.

 

14. Take the EVO component adapter, and install it on the new pump. Keep in mind, the threaded insert goes down a good ways against the spring pressure of the pressure regulator before you encounter the threads. Make sure to start it by hand, so you don't cross-thread the insert.

 

15. The position of the EVO component adaptor is CRITICAL. You'll notice that there's a flat surface running along the portion the threaded insert goes into, about halfway the length of the adapter. That flat surface should be PARALLEL to the pump pulley, that insures the pipe outlet is in the proper place for your power steering hose to connect, and that you'll be able to put the pump fluid tank back on without running into the adapter. Note that when that edge is parallel to the pump pulley, the pressure hose outlet is at an angle relative to the pump. Make sure that 30mm socket stays absolutely straight, and it's TIGHT. I tightened mine to 30 ft/lbs.

 

16. Now that the adapter is installed on the new pump, install the EVO pintle, making sure the silver washer is present, and align the groove in the top of the pintle parallel with the pulley.

 

17. Install the EVO component "hat"...not too tight, it's made of weak metal. Just snug it down.

 

18. Install the coil assembly back onto the "hat".

 

19. Reinstall the "e" clip, which holds the coil in place on the EVO component.

 

20. Reinstall the snap ring, noting the tab that sticks way out controls where the electrical connection points. The snap ring DOESN'T go into the groove the "e" clip goes in...both won't fit in that groove...but it simply clamps down on the serrated edge of the round "button" that forms the top of the EVO component. I found it easiest to open the snap ring with snap ring pliers, and control that end, while a helper made sure the tab part fit into the gap in the electrical connector.

 

21. Take the completed pump back off the engine, and install the NV7 fluid tank from your old pump onto the new one. A standard tank WILL NOT FIT, as it is shaped differently where the EVO adapter now is, so reuse your old tank.

 

22. Install your new pump back on your LQ1, and finish bolting everything back up.

 

Hope this helps someone!

Edited August 26, 2011 by Galaxie500XL

[Galaxie500XL]

Just a bit of an update...it's been over a month now, other than a slight whine from the power steering pump, which it seems every one of these cars has, there have been no issues.