GM power steering pump pressure reduction.

richard 36dodge · May 22, 2006, 01:10:50 PM

Anybody know how to reduce the pressure in a GM power steering pump to work with a Late (1979 up) Mustang rack ? The pump is an early style with the keyway and bolt.
Thanks, Rick Harris

parklane · May 22, 2006, 07:04:55 PM

Seem to remember Frank (Enjenjo) say that the pressure relief valve from an older Dodge Neon is what you need, and it fits right into the GM pump.

JOhn

enjenjo · May 22, 2006, 08:11:40 PM

Actually it's a Omni, or Horizon, but an old K car should work too.

richard 36dodge · May 22, 2006, 09:17:25 PM

Can you buy that valve separate ? or do you have to get the hole pump ?
THANKS !!!
Rick Harris

enjenjo · May 22, 2006, 09:54:15 PM

I generally get them at the salvage yard.

donnie g · May 22, 2006, 10:22:45 PM

on a g.m. pump take the large line off the back of the pump,then the valve assembly...on the bypass valve assembly there should be some stainless washers...the LESS WASHERS the more pressure....ie one washer! my 29 plymouth takes 4 washers ( 5 is the max allowed)
3500 lb car ... try three to start if it is still twitchy on the road go to four
let me know if you need pics...i'll be back in the shop in the morning!

donnie g · May 22, 2006, 10:23:49 PM

on a g.m. pump take the large line off the back of the pump,then the valve assembly...on the bypass valve assembly there should be some stainless washers...the LESS WASHERS the more pressure....ie one washer! my 29 plymouth takes 4 washers ( 5 is the max allowed)
3500 lb car ... try three to start if it is still twitchy on the road go to four
let me know if you need pics...i'll be back in the shop in the morning!

richard 36dodge · May 22, 2006, 11:05:24 PM

Quote from: "donnie g" on a g.m. pump take the large line off the back of the pump,then the valve assembly...on the bypass valve assembly there should be some stainless washers...the LESS WASHERS the more pressure....ie one washer! my 29 plymouth takes 4 washers ( 5 is the max allowed)
3500 lb car ... try three to start if it is still twitchy on the road go to four
let me know if you need pics...i'll be back in the shop in the morning!

I would love some Pictures ! Is the spring on the back of the valve or inside. I have an extra GM pump. One spring is about 1/2' dia and 2" long and the other spring is inside the valve and I have not taken apart.
My 36 Dodge Coupe weights 3100 lbs.
Thanks, Rick Harris

Leon · May 23, 2006, 03:31:57 AM

Quote from: "richard 36dodge"Anybody know how to reduce the pressure in a GM power steering pump to work with a Late (1979 up) Mustang rack ? The pump is an early style with the keyway and bolt.
Thanks, Rick Harris

I thought the Late rack was designed to handle the higher pump pressure. Is the steering still too sensitive with that rack? That's what I'm mounting on my 54 Chevy and was hoping that I wouldn't have to mess with it.

Ed ke6bnl · May 23, 2006, 07:51:15 AM

Quote from: "richard 36dodge"Anybody know how to reduce the pressure in a GM power steering pump to work with a Late (1979 up) Mustang rack ? The pump is an early style with the keyway and bolt.
Thanks, Rick Harris

What I did for my 84 t-bird rack and a chevy pump was ordered a http://www.borgeson.com/ pressure adjuster and instructions for about $16.00 + shipping and it worked great. includes washer and some ohter replacement parts. Ed ke6bnl

richard 36dodge · May 23, 2006, 07:52:30 AM

Quote from: "Leon"
Quote from: "richard 36dodge"Anybody know how to reduce the pressure in a GM power steering pump to work with a Late (1979 up) Mustang rack ? The pump is an early style with the keyway and bolt.
Thanks, Rick Harris
I thought the Late rack was designed to handle the higher pump pressure. Is the steering still too sensitive with that rack? That's what I'm mounting on my 54 Chevy and was hoping that I wouldn't have to mess with it.

I have a rack off a 1988 Mustang and it is too senitive for me. My '36 Dodge weights 3100 lbs. With 1660 lbs on the front wheels,
Rick Harris.

enjenjo · May 23, 2006, 09:16:56 AM

It depends on which late rack you have. The standard rack seems to work well with the GM pump as is. The sports/high performance rack feels twitchy to some people witout reduced pump pressure. The difference ib racks, the standard rack is about 3 turns lock to lock, the performance rack is just over two turns lock to lock.

richard 36dodge · May 23, 2006, 10:58:12 AM

Quote from: "enjenjo"It depends on which late rack you have. The standard rack seems to work well with the GM pump as is. The sports/high performance rack feels twitchy to some people witout reduced pump pressure. The difference ib racks, the standard rack is about 3 turns lock to lock, the performance rack is just over two turns lock to lock.

I have a 3 turn rack off of a 6 cyl '88 Mustang. I just went to the autozone and got a '80 Dodge omni pump. Do I use the valve and spring as well as the pump fitting ? It looks like the fitting has a smaller hole than the stock GM pump.
Thanks, Rick Harris

enjenjo · May 23, 2006, 11:05:23 AM

use the valve and spring, and whichever fitting is right for your application.

richard 36dodge · May 23, 2006, 11:09:29 AM

Quote from: "enjenjo"use the valve and spring, and whichever fitting is right for your application.

So the hole size in the fitting doesn't matter ? I have the fitting adapted to AN #6.
Thanks, Rick Harris.