Power steering pressures

Help Support 7173Mustangs.com:

digithead

Well-known member
Joined
Jan 24, 2016
Messages
264
Reaction score
2
Location
UPSTATE NY
My Car
1973 Mustang 351C-4V 4BBL 4 SPEED CONVERTIBLE White
Is there anyway to lower the power steering pressure to not make it so over boosted? I understand its helpful at 1 mph in parking lot, but i'd like it less boosted at 60mph. My 73 Convertible is a fairly tweaky at cruise. I think it would handle better at lower pressure if its possible.

 

73pony

VIP Members
Joined
Jul 6, 2015
Messages
4,241
Reaction score
91
Location
Iowa
My Car
1973 Mustang Grande 351C 2v
Let me know what you find out. I have the same issue.

 

Bentworker

VIP Members
Joined
Jan 17, 2015
Messages
1,479
Reaction score
188
Location
California
My Car
71' Grande project.
If you have one or put on a Saginaw style power steering pump it is pretty easy to adjust output pressure. I don't have a picture, but you just remove the high pressure fitting from the back side of the pump and the regulator assembly with piston will come out the back. If you make the regulating piston longer with more washers under the nut it will decrease the pressure. I am not too sure how much this will change the feedback.

The lack of feedback isn't all pressure, there is a small torsion bar inside the steering box, it has to deflect when you turn the steering wheel in order to port oil to pressurize one side of the piston or the other. The smaller the torsion bar the less feedback you have because it deflects easier. It isn't something that is easily changed because I don't know of any other applications that have a 36 spline 13/16" input that have a larger torsion bar than what is stock in the mustang. The bar you have in your car is somewhere from .180-.186" depending if you have the fixed ratio box or the variable one.

There were ones made up to .210" in production GM cars. The mid 80's and early 90's V8 firebird and Camero had the big torsion bars. Problem is that if you swap them you now have to make a custom rag joint / steering coupler that will go on the 3/4" 30 spline input shaft.

Like Don said check out my steering box thread for some ideas.

There is no harm in messing with your pump if you have the Saginaw one. The only catch is that the regulating piston is a precision part, it is best to hold it with a lathe collet to remove the nut on the end. You can buy a fixed 5C collet holder and a cheapie import collet that is the correct size off of eBay for less than $50. Put the fixed collet holder in a vice and you should be good to go.

 

Don C

Fords Forever
Joined
Jan 1, 2012
Messages
7,929
Reaction score
699
Location
Springfield, OR
My Car
1971 Mustang Sportroof M code
You can get a Saginaw style variable pressure pump from Flaming River, but it's a GM style, so I don't know if our brackets would work.

 

Bentworker

VIP Members
Joined
Jan 17, 2015
Messages
1,479
Reaction score
188
Location
California
My Car
71' Grande project.
You should be able to replace the springs which would adjust the pressure. Here is an article I found.

http://www.hotrod.com/how-to/engine/1209cct-perfect-power-steering/
That is for the Saginaw style pump, the article shows some good pictures of the regulator piston and washers / shims. You do not replace springs, just add shims.

Looks like the kit that is shown in the article is available from Summit for pretty cheap, and even comes with a little aluminum sleeve to help hold the piston if you don't want to go crazy and order a collet.

Link to Summit for Borgeson 899001

 

digithead

Well-known member
Joined
Jan 24, 2016
Messages
264
Reaction score
2
Location
UPSTATE NY
My Car
1973 Mustang 351C-4V 4BBL 4 SPEED CONVERTIBLE White
You should be able to replace the springs which would adjust the pressure. Here is an article I found.

http://www.hotrod.com/how-to/engine/1209cct-perfect-power-steering/
That is for the Saginaw style pump, the article shows some good pictures of the regulator piston and washers / shims. You do not replace springs, just add shims.

Looks like the kit that is shown in the article is available from Summit for pretty cheap, and even comes with a little aluminum sleeve to help hold the piston if you don't want to go crazy and order a collet.

Link to Summit for Borgeson 899001
Thanks, I would like to try this kit. Now the really dumb question. I have no idea of what brand/type pump I have. Sure looks stock as all hell. How do I tell?

 

Bentworker

VIP Members
Joined
Jan 17, 2015
Messages
1,479
Reaction score
188
Location
California
My Car
71' Grande project.
You should be able to replace the springs which would adjust the pressure. Here is an article I found.

http://www.hotrod.com/how-to/engine/1209cct-perfect-power-steering/
That is for the Saginaw style pump, the article shows some good pictures of the regulator piston and washers / shims. You do not replace springs, just add shims.

Looks like the kit that is shown in the article is available from Summit for pretty cheap, and even comes with a little aluminum sleeve to help hold the piston if you don't want to go crazy and order a collet.

Link to Summit for Borgeson 899001
Thanks, I would like to try this kit. Now the really dumb question. I have no idea of what brand/type pump I have. Sure looks stock as all hell. How do I tell?
Saginaw pump is the canned ham looking pump on the left.

ps-pumps.jpg

 

digithead

Well-known member
Joined
Jan 24, 2016
Messages
264
Reaction score
2
Location
UPSTATE NY
My Car
1973 Mustang 351C-4V 4BBL 4 SPEED CONVERTIBLE White
That is for the Saginaw style pump, the article shows some good pictures of the regulator piston and washers / shims. You do not replace springs, just add shims.

Looks like the kit that is shown in the article is available from Summit for pretty cheap, and even comes with a little aluminum sleeve to help hold the piston if you don't want to go crazy and order a collet.

Link to Summit for Borgeson 899001
Thanks, I would like to try this kit. Now the really dumb question. I have no idea of what brand/type pump I have. Sure looks stock as all hell. How do I tell?
Saginaw pump is the canned ham looking pump on the left.
THanks. So I dont have a Saginaw, I guess its the original Ford Thompson style. This looks interesting if it wasnt hard to plumb. Other Ford owners have used them. Its a simple external bypass and its adjustable. So you can dial in amount of bypass to weaken pressure. Anyone ever done something like this? http://www.speedwaymotors.com/Heidts-PS-101-Adjustable-Power-Steering-Valve,14895.html

 

4mm

Well-known member
Joined
Aug 26, 2012
Messages
447
Reaction score
2
Location
S. TX
My Car
1971 Mustang 351C 4V Fastback
I've been looking for a Saginaw mounting kit that looks stock for a 351C. Haven't found anything I like except for the KRC items but they are pricey and don't look stock.

I have found plenty of options for the Windsors but practically nothing for Clevelands.

 

digithead

Well-known member
Joined
Jan 24, 2016
Messages
264
Reaction score
2
Location
UPSTATE NY
My Car
1973 Mustang 351C-4V 4BBL 4 SPEED CONVERTIBLE White
I've been looking for a Saginaw mounting kit that looks stock for a 351C. Haven't found anything I like except for the KRC items but they are pricey and don't look stock.

I have found plenty of options for the Windsors but practically nothing for Clevelands.
Thanks, let us know if you come up with a solution!

 

wwhite72

VIP Members
Joined
Mar 9, 2013
Messages
997
Reaction score
2
Location
us
My Car
72 convert 351c
7173 Mustangs use a Thompson pump and a Saganaw steering box. And yes, over powered like all American muscle cars. But if yer car is a little twitchy on the highway it is more likely your alignment. Add some castor? Check your toe-in? I had a good mechanic argue with me about the toe-in on a street car once. He only worked on 1/4 mile cars. I had to show him the factory specs. Also, the road you drive on might have something to do with it; the NJ Turnpike has ruts in all the lanes other than the left due to the never ending tractor trailers on it. Trying to drive in any lane other than the left is like trying to herd a cat. Get to the fast lane and its smooth sailing. Finally, there is a variable ratio steering box that can be had for our cars but it will have same amount of boost and might actually seem MORE twitchy to you at speed.

 

73pony

VIP Members
Joined
Jul 6, 2015
Messages
4,241
Reaction score
91
Location
Iowa
My Car
1973 Mustang Grande 351C 2v
Thanks, I would like to try this kit. Now the really dumb question. I have no idea of what brand/type pump I have. Sure looks stock as all hell. How do I tell?
Saginaw pump is the canned ham looking pump on the left.
THanks. So I dont have a Saginaw, I guess its the original Ford Thompson style. This looks interesting if it wasnt hard to plumb. Other Ford owners have used them. Its a simple external bypass and its adjustable. So you can dial in amount of bypass to weaken pressure. Anyone ever done something like this? http://www.speedwaymotors.com/Heidts-PS-101-Adjustable-Power-Steering-Valve,14895.html
I would be curious if anyone has tried this valve. Reviews seem good on it. I am considering giving it a shot.

 

73pony

VIP Members
Joined
Jul 6, 2015
Messages
4,241
Reaction score
91
Location
Iowa
My Car
1973 Mustang Grande 351C 2v
Looks like a decent piece. Only issue I have is I have a brand new PS Pump (finally no groaning) and I have factory AC. My brother in law mentioned he could machine out a bracket for me if I wanted that would work with the saganaw pump and AC but I am thinking the valve might be a better solution for now, plus he is swamped at work making some turbo parts for the dodge hellcat motor.

 

4mm

Well-known member
Joined
Aug 26, 2012
Messages
447
Reaction score
2
Location
S. TX
My Car
1971 Mustang 351C 4V Fastback
Last edited by a moderator:
Top