Reverting MR2 back to Power Steering

History: Power Steering to Manual Steering

This car was converted to manual steering using the instruction from KO Racing. Because it was once with PS, the easy route is to using everything stock and save the trouble to improvise, if I can find all stock parts.

Preparation: research the list of parts

Electrics

1. P/S computer: 89650-17040: specifically for 93 only
2. P/S driver module: 89652-17021
3. P/S high amp relay: 89654-17010

PS system

1. P/S pump: 80960-17010
2. P/S reservoir
3. high pressure feedline
4. low pressure return line

Steering

1. Detroitaxle Remanufactured Power Steering Rack & Pinion Assembly
2. P/S Steering shaft/u-joint: specifically for 93

Diagrams

Purchases:

1. The electric stuff and steering rack are from ebay
2. The pressure lines and some connectors are from ebay,
3. Some connecting hoses, the return line and connectors are from some Toyota dealer
4. the feed line is from amazon.

Putting together

1. putting all the electric components together

First good sign: P/S warning light is on when switching to on, then goes away

2. take the old column and rack off

This part is overall easy, other than taking the tie rod end off the disks. The inners are the manual ones, the outer are the PS ones.

3. Hooking up the hoses

4. Put the Rack and shaft back

This part is very hard. Not sure if I’ve done it wrong, but I learned the hard way that I have to put the shaft in first, then hook the rack to the hose, then put the rack back in.

4. Vacuum Test
It might be just mine, but the lid housing doesn’t seem to be airtight, so it’s not possible to vacuum test from the opening there, I ended up unhooking the feed line, the return line, and test in between.

5. PS fluid

I got the Amsoil PS fluid since it’s the only one out there claim to design for EHPS. Note that you will need more than one 16 fl oz bottle to fill the system.

6. Bleed the system

The BGB provides some basic ways to bleed the system.

References:

1. 1993 repair manual