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Discussion Starter · #1 ·
Hey guys,

Currently trying to wrap my head around how I can adapt my stock Power Steering pump to my Mustang II rack and pinion from Rod and Custom. Couple Questions...

1. Does anyone know how much pressure the stock 351C PS pump puts out? Considering the MII Rack and Pinion is rated for about 700-800psi, will the pump be too strong for the rack?

2. If pump is fine for application I'm good with making the custom high pressure line using Russells PTFE Hose and equivalent fittings. Though for fitting a return line, I have an issue where I have to adapt the AN-6 adapter from the MII Rack to the crimped/nippled return line on the pump (crimped return line that comes off of little PS radiator, shown in photo below). How could I adapt to this crimped hardline? I was going to cut it and flare for a AN fitting but can't get my line cutter on the line due to the other line being in the way so that's out of the question.

Would someone like NAPA be able to make me a new return line that could fit on the crimped line of pump and put a hard fitting to MII adapter almost like stock?
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In general the Ford/Thompson pump operates in the mid-600 range for psi. It’s internally regulated, a PITA to mod the pressure and dead-heads at maybe 1200 or so.
In my current Christmas food coma there’s no way I could suggest good plumbing solutions……

ex-Global West GM
1991-1995
 
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Discussion Starter · #4 ·
Yeah my dumba** also threw out the original lines. Do you guys know what size the original High pressure Soft lines were? When I look at the the lines on CJ Ponies they don't give the line width. I've looked around on the forums can't seem to find the fit, I bought -6 Powerflex not sure if I should of bought -10 though...
 

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Not in my notes but from memory I think 1/4 on the line on the early cars and 5/16 on the later.......
(Last spare OE pressure hose I had for my '66 is on the car now)

ex-Global West GM
1991-1995
 

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Discussion Starter · #6 · (Edited)
Not in my notes but from memory I think 1/4 on the line on the early cars and 5/16 on the later.......
(Last spare OE pressure hose I had for my '66 is on the car now)

ex-Global West GM
1991-1995
Hmm alright i ll keep looking around. Only reason i was thinking -6 was because theres a hard line that comes off the high pressure line first that was flared and would connect to line that goes to rack. That hard line is a 3/8. Actually i guess it doesn’t really matter what original lines were right? Because its the same rack as 74-79 mustang which had 3/8 for high pressure. Im assuming the 74-79 pumps made similar psi from the pump?
 

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The lines both have 3/8" inside diameter
Back in the day
If I needed to replace a 2 piece rack in a MII Ford would send fittings to make the OEM lines work
Used to get 4 fittings in the bag with the new rack
Any pump you find will work. They all have similar specs (I ran a C2 pump with the plastic housing for years on my 69)
 

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Hmm alright i ll keep looking around. Only reason i was thinking -6 was because theres a hard line that comes off the high pressure line first that was flared and would connect to line that goes to rack. That hard line is a 3/8. Actually i guess it doesn’t really matter what original lines were right? Because its the same rack as 74-79 mustang which had 3/8 for high pressure. Im assuming the 74-79 pumps made similar psi from the pump?
On my '66 the pressure line at the valve is .253" OD and the return at the valve is .402" OD. Subtract a small amount for wall thickness
and you arrive at ID.

Pretty sure that 74-79 P/S pumps had a different psi but I don't know...... we didn't use them.
I will guarantee you that the following gen (5.0 pumps) were different, as we did fool around with those. I don't recall but remember a higher
operating pressure than the Thompson/Ford....... 900 maybe.

ex-Global West GM
1991-1995
 

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IMHO I see no reason to switch to AN fittings just to make it work
The return side carries no pressure anyway so a hose clamp and rubber trans cooler line is all you need
Fittings for the pressure side are completely different
Means plan on 1500 psi working pressure on the pump and lines and 5k psi on stops
I am one of the chosen few who have actually hooked up the Ford pressure gauge set to a power steering system and watched them work
I et al. did it in school of course because no one in their right mind would ever do that unless provoked real hard
I see a few posts on here concerning the lines into the control valve and ram
You can use double flare brake line fittings and the early control valve repair kits had new flare inserts for the lines
 

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Discussion Starter · #12 ·
IMHO I see no reason to switch to AN fittings just to make it work
The return side carries no pressure anyway so a hose clamp and rubber trans cooler line is all you need
Fittings for the pressure side are completely different
Means plan on 1500 psi working pressure on the pump and lines and 5k psi on stops
I am one of the chosen few who have actually hooked up the Ford pressure gauge set to a power steering system and watched them work
I et al. did it in school of course because no one in their right mind would ever do that unless provoked real hard
I see a few posts on here concerning the lines into the control valve and ram
You can use double flare brake line fittings and the early control valve repair kits had new flare inserts for the lines
The return line yes i'm just going to clamp a return hose on and on the rack guess I'll just use a barb fitting - AN-6 like C6ZZGT suggested. That fitting should hold correct? I've heard about fittings being used that weren't "power steering" fittings and they've blown apart. Not sure if that matters on the return side though.

My whole concern was I just didn't know the correct size line to use for the pressure side. You say 3/8 and thats what the hard line is so I'm going to run the -6AN powerflex I bought. I wanted to use AN lines because I didn't feel like having to pay a place to make custom lines and hadn't heard of the early control valve repair kits..

"Means plan on 1500 psi working pressure on the pump and lines and 5k psi on stops" are you saying that the powerflex hose which handles 2500 psi won't hold if rack is brought out to full stop?
 

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Hmm alright i ll keep looking around. Only reason i was thinking -6 was because theres a hard line that comes off the high pressure line first that was flared and would connect to line that goes to rack. That hard line is a 3/8. Actually i guess it doesn’t really matter what original lines were right? Because its the same rack as 74-79 mustang which had 3/8 for high pressure. Im assuming the 74-79 pumps made similar psi from the pump?
My brain-fart.......... your old pressure line (that you threw out) if it was originally for a Saginaw/Ford integral steering box, likely ended in an inverted flare nut
spec'd at 5/8-18 (3/8's based line). So yes, 6AN / -6
Sorry about that.

ex-Global West GM
1991-1995
 

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Ja.mc44,
The AN fittings will hold the tremendous pressure just as well as the double flare or o-ring fittings will
Use whatever works and looks good in the space available
The fittings and such are the salt anyway by the time you have 20 hours into the job
 

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Discussion Starter · #15 ·
My brain-fart.......... your old pressure line (that you threw out) if it was originally for a Saginaw/Ford integral steering box, likely ended in an inverted flare nut
spec'd at 5/8-18 (3/8's based line). So yes, 6AN / -6
Sorry about that.

ex-Global West GM
1991-1995
haha perfect thank you for the info
 

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Discussion Starter · #16 ·
Ja.mc44,
The AN fittings will hold the tremendous pressure just as well as the double flare or o-ring fittings will
Use whatever works and looks good in the space available
The fittings and such are the salt anyway by the time you have 20 hours into the job
Thanks, first time doing custom line work so still learning, you put my mind at ease :)
 
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