Adapting a Saginaw steering pump

[tony-muscle]

After my Ford pump started foaming a year after it was rebuilt I decided to replace it. After much research I decided I wanted to give the Saginaw pump a try. It didn't seem that hard to fit one in our cars. After all the steering box is Saginaw. Note that in my case it is a 351 Cleveland with A/C.

I started by researching multiple picture of Saginaw pumps. It happens that while the internals are the same, the inlet and outlet connections vary wildly. I settled with a Stuff Stuff 6184B (https://www.summitracing.com/parts/TFF-6184B) - EDIT: read below, this pump eventually did not work. Based on pictures it had connections comparable to the Ford pump. Once I received it I was able to play around with brackets. You can buy brackets specifically to adapt the Saginaw pump to the Cleveland but they are way too expensive. Also, the fact that I have A/C it complicated matters. I decided that I would try using the current bracket with the least modifications as possible. The Saginaw pump has three bolt holes in the front face following a different pattern than the Ford pump. However, it just happens that the two top bolts of the pump match the two bottom bolts of the bracket (lowers the location of the pump in the engine bay). Awesome, so I could adapt the bracket to the pump without major modifications. Even though the pump felt tight with two support points I wanted to add the third. Then came the light. The back side of the pump has another bolt hole for this purpose. Since the OEM bracket has a hole at the rear of the bracket I just needed to bend a thick metal profile to fit within the two. I had some stock 1/8" thick profile about 3/4" wide laying around. This is a bear to bend but with help of the vise and a lot of leverage it ended up being relatively easy. I bent the 1/8" thick metal in a S shape to fit between the pump and bracket. That gave me a very good support for the pump.

Then was pulley selection. I figured I wanted to find a pulley of similar diameter to the one on the Ford pump. Unfortunately, the shaft diameters are different so I couldn't reuse the OEM one. I also wanted to be able to use the wider belt as the OEM. Most steering pump pulleys were only 3/8", but I wanted to use the 1/2" groove to use the 15 or 17 belts. It took a lot of research and communication with vendors all over the country. At some point I bought a Dorman pulley that had the same diameter but was 3/8" wide. Eventually I found a seller in ebay that listed the OD and width of all the pulleys in stock (hartbroscoreco). Finally, the power steering pulley for a 1968-72 Oldsmobile Cutlass with a 442 (stamped "MA") had the right dimensions. I don't know anything about Olds but I knew it had the dimensions I was looking for. Once I received it I cleaned and painted. EDIT: you can also use the Borgeson 801105 pulley with is smaller (see this post: https://7173mustangs.com/forums/topic/31980-adapting-a-saginaw-steering-pump/?do=findComment&comment=346422&_rid=2681). The Borgeson pulley is 5 9/16" compared to 6.5" for the stock.

Then it was to figure out the backspacing of the pump with respect to the bracket. The face of the Saginaw pump is further recessed from the pulley than the Ford pump. By measuring the shaft length, pulley and distance to the mating face I figured out the back spacing needed. I cut bushings to this dimensions and installed the bolts. I used washers to finalize the dimensions and made sure the face of the pump was parallel to the bracket. Even though I talked about the S bracket earlier, it was at this point when I bent the bracket. Finally, I had a solidly mounted Saginaw pump to the OEM bracket with the same diameter pulley.

I then pressed the pulley and installed in the engine which I had out of the car. The alignment looked very good at this time. The fitting was easy. I needed a 3/8" male flare union (Anderson Metals 704042-06) and Gates elbow tube connection #349760. With the elbow tube tightened to the right angle so it doesn't hit the shock tower I was able to use the stock length pressure hose. The return hose was easy since the tube in the pump was already facing up.

The whole pump ends up located lower in the engine bay so the pressure hose is closer to the headers. I covered the elbow tube and pressure hose end with insulation. There is about a 1" gap between the angle tube and the shock tower. The pump belt is also closer to the lower radiator hose, but there is still about a 1" gap. This may vary depending the location of your lower radiator hose. For belt, I needed a slightly longer belt. That was Gates 9530 V-belt.

Here are some pictures. I will post pictures of the pump in the car later today.

PS EDIT: read post below where I explained that eventually the Tuff Stuff pump didn't work: https://7173mustangs.com/forums/topic/31980-adapting-a-saginaw-steering-pump/?tab=comments#comment-390857

S bracket:



Back side view of pump with S bracket and angle tube.



Side view. Note that the two top bolt holes in the pump match the two bottom holes in the bracket. This moves the pump down a little bit.



One of the spacer bushings:



Front view:

 

[tony-muscle]

Clarification: the diameter of the pulley is 6.5". Both the OEM and the Olds.

Here are pictures of the pump in the car:



Sent from my SAMSUNG-SM-G930A using Tapatalk

 

[OzCoupe72]

Great write up!

Also for anyone swapping pulleys definitely get a quality removal/installer tool, cheap ones barely cut it, ask me I know

 

[rackerm]

Nicely done. Great detail! Finding another 1968-72 Oldsmobile Cutlass with a 442 (stamped "MA") pulley could be a challenge if I were to give it a try.

 

[tony-muscle]

Great write up!

Also for anyone swapping pulleys definitely get a quality removal/installer tool, cheap ones barely cut it, ask me I know

A removal/installer tool is important to complete the task. Surprisingly, I found out that the Harbor Freight one worked great.

 

[tony-muscle]

Nicely done. Great detail! Finding another 1968-72 Oldsmobile Cutlass with a 442 (stamped "MA") pulley could be a challenge if I were to give it a try.

Agreed. This is definitely the biggest challenge of the project. I think the pump would still work with a pulley slightly bigger or smaller. However, I don't know how much smaller or bigger so that's why I decided to go with the same diameter. A bigger diameter will turn  slower, which will rob less HP but may make the steering harder. I don't know the details of flowrate demand and production of the system to have an educated guess of what will happen.

There may be other pulleys 6.5" in diameter and 1/2" groove out there that I don't know off. You may be able to make it work with a 3/8" groove. The Dorman 300-122 option is cheap and 3/8" wide. However, I don't know if that will give the belt enough grip to turn the pump and/or water pump. The power steering belt also drives the water pump. I also looked into pulley manufacturers but didn't have much luck. I was also trying to keep pricing reasonable. The pulley I bought was just under $50, which I thought it was already pricey. Manufacturers like March Performance offer some options that may work, but at a higher price. Another issue with pulley selection to keep in mind is if the pulley has the shoulder where you can attach the pulley puller for easy removal. The March Performance, per example, don't seem to have this shoulder. The final issue is the shaft bore.

I am hoping that by posting this in the forum someone will come up with a good and cost effective source for a pulley. The offset of the pulley is less critical because you can compensate with the length of the spacer bushing. However, you can't have a negative offset.

Pulley dimensions: 6.5" diameter; 1/2" wide groove; 3/4" press fit shaft bore

Edit PS: read the next post.

 

[tony-muscle]

As an update. I have been using this system for 500+ miles now. All works as expected, except that it gets hard at idle so when that happens I need to tap the gas pedal. In hindsight, a slightly smaller pulley may have worked better. I installed a 6.5" pulley. The Borgeson setup comes with a 5 9/16" pulley. The borgeson pulley would be p/n 801105. This will move the pump a little faster, which should help steering at idle.

 

[Don C]

Thanks for the update Tony. Great job on documentation. It's always nice for us non-concourse owners to have options.

 

[Denise1972]

Tony Thanks for the post very informative. I have a question how does your car drive at speed does it have less assist in the system than the ford pump gives, or is it about the same? Thanks Jack

 

[tony-muscle]

Tony  Thanks for the post very informative. I have a question how does your car drive at speed does it have less assist in the system than the ford pump gives, or is it about the same? Thanks Jack

I didn't feel much of a difference. As in the previous post, at idle it should work better with the Borgeson pulley, and it is also easy to find. I already bought the pulley but I have not installed it so I can't give feedback yet.

Edit: with the smaller pulley I think you will also need a shorter belt than indicated in the first post, which may bring you back to the original belt.

 

[jowens1126]

Awesome job Tony! It's on my list.

 

[tony-muscle]

Another follow up. So I installed the smaller Borgeson pulley. This one is 5 9/16" in diameter before the one I had that was 6 1/2". With the smaller pulley the pump should be rotating faster at idle. My thought then was that if it rotates faster the steering should not get that hard. However, I was wrong. The steering seems to get harder faster than before at idle. Something is not making sense. If I am driving and as I slow/coast down before a turn, as the RPM get near 1,000, the steering gets very hard which is kind of scary. I most be missing something? Is it pressure or flow rate related?

 

[Don C]

My guess is the pressure relief valve is stuck open or has a missing or broken spring.

 

[tony-muscle]

My guess is the pressure relief valve is stuck open or has a missing or broken spring.

If that's the case, will it still work at higher RPMs? Once I am in the low 1,000s it works great.

 

[tony-muscle]

If that's the case, will it still work at higher RPMs? Once I am in the low 1,000s it works great.

Ok, I think I can answer my own question. Yes, it can happen when partially stuck. This is a good article about it.

https://benchworksteering.com/tech-talk/pressure-relief-valve/

Now that I remember, I think I may have checked this valve in the past. Easy job, but messy!

 

[tony-muscle]

Follow up number 342

So I think I finally got all this figured out. My pump was junk. Do not purchase a Tuff Stuff pump. After all these years, and a very long trip, I thought it was time to wrap my head around this issue that I can't turn the wheels below 1,500 rpms. I called Lee Power Steering and purchased their Saginaw P-pump replacement (https://leepowersteering.com/collections/power-steering-pumps/products/saginaw-p-series-power-steering-pump-1960s-1990s-gm-cars). I basically used the can of the Tuff Stuff pump but replaced the actual pump with Lee's. What a difference. I can turn my wheels with little effort at idle. It is very likely that the Tuff Stuff pump was broken. The magnet inside the pump had a thick sludge over it plus a few large metal pieces. Obviously something was wrong. The Tuff Stuff pump is rated to 1,200 psi while the Lee pump is rated to 1,450 psi. I don' think that this pressure differential was the issue, but just a bad junk pump.

PS: next I may try to go back to the 6.5" pulley since the steering is now effortless at idle.

 

[rackerm]

Glad to hear that you solved the power steering problem. Should make driving it more enjoyable from now on.

 

[73' mach 1]

Sorry if this is off the mark but psi is one thing flow rate is another.. Would a change to the control valve inside the pump help? 

 

[rackerm]

Sorry if this is off the mark but psi is one thing flow rate is another.. Would a change to the control valve inside the pump help? 

I have not used one, but I have read that a Power Steering Flow Fitting Control Valve can help by increasing flow. As I understand it, the more flow your steering system receives the easier it will be to turn the wheels, but will decrease feel. Having less flow will put feel and stability back in the steering system, but decrease assist.