Provided as a source of information Power Steering pumps, specifically Federal.

My focus was the 1969 Federal Pump (especially Hemi cars) which looks like the Thompson (TRW) Pump.

Up through 1966 inclusive there were only 2 styles of Power Steering pump for passenger cars. They were a Saginaw design and Thompson/TRW. (No Federal Pump)

Saginaw is the .94L pump with oval filler tube and a keyed shaft with nut.
TRW has a round filler tube and round reservoir. This is a look alike to the Federal Pump.

In 1967 the Federal pump is introduced and the parts manual in 67 and 68 clearly describe them and how to tell the difference.

4 pumps used
.94L Key shaft Saginaw (oval filler tube)
.96L Solid end shaft 4 5/8” ID reservoir TRW Small Pump
1.06L 3/8” threaded internal hole shaft 4 7/8” ID reservoir (The Federal)
1.20L Hex Hole shaft 5 1/8” ID reservoir TRW Large Pump

There is also good pictures on the internet of the back of the Federal versus TRW pumps to help tell the difference. Without a front or back view you cannot tell the difference.
Some internet sites also state the each of the pumps have different shaft diameters also. I am in the process of validating that.

Also TRW cap is different than the Federal, but they interchange. Most caps I see are Federal, even on TRW pumps. Only matter for OEM grading.

What I have seen is the Thompson/TRW pumps (both small and large) that I have seen have TRW cast into the pump. The Federal has 2537955 cast in the pump.

The clear distinction between the similar looking TRW and Federal is the diameter of the 3 pumps. NOT interchangeable. Also Bracket mounting, since the back is different between TRW and Federal. And if the shafts are different diameter, pulley exchanges will not work either.
TRW was a vane type pump and Federal roller pin type, so each had its own repair kit.

So we get to 1969 and we are back to 2 main pumps. Thompson/TRW is gone and only Federal and Saginaw are used.
The Federal pump is touted as superior because it is a 2 stage pump. It flows high at Low RPM and bypasses fluid at High RPM to reduce flow. This lowers power requirement, reduce temperature and should give a better feel.

When looking at the parts manual the B body hemis through 1968 used the small TRW pump. Most searches I have seen says the Federal was used on 68 hemis. Maybe this was a change that the parts manual did not get updated with. This is where shaft diameter may come into play, as the pulley used is shown as the TRW small pump. If so, and shafts are different, 68 hemis should have the TRW small pump. I am no expert in this area, and have not paid much attention to 68 and earlier hemis, so this could just be a case where the parts document is wrong. Unless you know you are looking at an original unmolested car it is impossible to verify via the internet.

So back to the 1969 and up Hemi which did use Federal 1.06 pump. What I do not think many folks know is there were 3 variations of the pump, all with different part numbers. The pumping mechanism and repairs kits where the same, because the internals were all the same except one component. The one component not service individually on federal pump was the flow control valve. It was a custom fit to the housing and if needing replacement, you had to by a new pump assembly. Not the reservoir, just pump. The flow control valve was also the relief valve.

So what was the difference? Operating pressure. The A bodies were 750 to 850 psi, B bodies and hemi 950 to 1050psi. Also shared with the big block A bodies in 69 and the AAR/TA in 70. The C bodies except 318 1100-1300psi.

The parts manual calls out the 3 different part numbers for pumps, 289131, 130, 129 respectively. The Service manual describes the pressure differences, and the Chrysler training video clearly spells out these difference and states that Flow control valves cannot be swapped between pumps, nor can pumps be exchanged between body styles. “Get the correct pump part number for the car and install it”. How critical was all this??? I don’t know. They also are very clear in stating the pump hose also plays an important role in operation and quietness of the pump. The tube bends and such probably provide the back press necessary along with the pulley/motor combination that made the flow control valve operate correctly for the car model. There also where difference in steering gear pump part numbers. So it was a system set up. Motor, pulley/hose, steering gear, and pump.

So where does all this lead us. Current parts stores do not make a distinction. You either get a Federal pump or the Saginaw. Go to the rebuilder sites and it is the same. They just send you a federal pump, no distinction of the different operating pressures.

This was back to my dilemma of trying to determine if there were specific markings on the pump body to identify its part number. Given how mopar put part numbers on almost everything, and even power steering hoses had the part number stamped on the metal band, how could you let 3 variations of a pump with different operating pressures go unmarked without a specific identification?

I have found different stampings on the pumps, and even different sized flow control valves, but I do not know what they came from, nor if they were rebuilt. I have access to a large pile of pumps. So if I could decipher a code that identified the pump pressure then I could determine the proper use.

I believe getting a C body 1200 psi pump on an A body meant to have a 800 psi pump would have a totally different feel. Of course most folks are not auto-crossing their mopars, so maybe it doesn’t really matter.

When I questioned some rebuilders, they did not have an answer and stated the system would still be ok and regulate itself. Again they do not make a distinction. They just rebuild the pump. An easy task by the way for a federal pump. Since the flow valve is simple and stays with the housing, as long as they are not mixing and matching on the repair line you may be ok if you sent your original in for a rebuild. But if you buy at the local parts store a remanufactured federal pump, you do not know which of the 3 variations you are getting. Again, maybe this does not matter, but maybe you have had some pumps that did not feel right on your car.

So if anyone has information on pump markings it would be great if you can provide that info, and maybe we can get a reference on Federal power steering pumps. Attached are 2 different federal pumps with different stamp markings, and you can see the difference in the flow control valves. The flow section is the same, but the pressure relief is controlled by spring and shims. Thanks for the read.

I have at least 4 Federal Pumps that I can pull info off of.

One is in my early 68 Hemi Charger. That car is a time capsule and I highly doubt it have ever been out of the car.

However I can't help until the end of next week. So ping me on Friday if I forget, because I will.

Another pump I have is off a TA I believe.

I got to do some more work on this. Still can't decipher the markings fully, but have some measurements on 4 Control Valves.

The 3 long ones all measure about 1.497" with internal depth of 1.304"
The short one is 1.387" with internal depth of 1.191"

2 types of springs. One is about 1.09" long, the other is .974",

The shims used under the head where .037, .045, .060. ,060".

For a course measurement, I added the shim thickness to the depth of each corresponding valve, and then subtracted the corresponding spring length to get a relative height. The larger the measurement, the lower relief pressure as the spring is compressed less and has less force on the ball bearing seating the relief port.

I had:
Long valve with long spring at .261"
Long valve with short spring at .375"
Short valve with short spring at .277"
Long Valve with long spring at .253"

The first and last set ups had the largest discrepancy in spring length, but it also had the largest difference in shims also.

Also, each valve had and engraved letter in the top. I had a D, E, B, M

So I have data, but I still can not decipher the markings or come up with dates. Plus I do not know what they came off of. The early 67-68 pumps should have only been on 318 C bodies based on the parts and service manuals though.

Thank you for taking the time to research and post this.

Dragon slayer
Thanks for posting the information on the Federal PS pumps
Still useful information
340challconvert

Thanks a lot dragon. About the time I think I have it all figured, some one digs up all the facts and reminds me how much I still don’t know. Lol. HOWEVER, to your credit, this is perfect timing. I can’t contribute any facts from known pumps but I need an answer if you can dig it up from your little book of secrets. I have a car in the shop now that is a mix up of parts but, thanks to this post, I can tell you it’s a Federal pump. Or as I call it, the 3/8 threaded hole pump. It leaks around the can. I need to find a seal kit for it to keep it from leaking. I was told you need to use a good sealant like “Right Stuff” on it in addition to a new seal on the outside can. Do you happen to have to part no for the Federal pump seal kit? Rock auto is not real clear in their description. Thanks.

Thank you for the compliments.

Edelmann 8507 Rebuild Kit.