Resealing a 1953 (1952) factory Mercury/Ford Power Steering unit

[Merc Cruzer]

Recently I found and purchased the last option for my 1953 Mercury Convertible, an original power steering unit. I had been driving it for the last 7 years with radial tires and manual steering. Great on the highway but a bear when trying to park or get out of a parking spot at a cruise or show. The car already has power windows, power seat, power top and power brakes. The unit I purchased had been sitting on a shelf for the last 10 years. Since I really didn't have the set up to bench test it, I decided I would install it and see if it still worked, then address any issues it may have. Well no surprise, it leaked quite profusely from the valve body.

By way of a little history on the seals used, they were, and if you purchase NOS seals or even what is being sold as replacement seals, are of the "U-cup" design. (Yellow seal). I have members of the local club that have told me that even after replacing the seals twice they still leaked. So I decided to use a different designed seal.

The design I chose is called a "loaded" seal (red seal). This is accomplished during the manufacturing by inserting a rubber "O" ring into the valley of the seal, thereby forcing the sides out at all times, creating a better seal, not just when under pressure. This is a real plus during those winter months or when the car sits for long periods of time, and the sealing properties seem to relax allowing the unit to leak.

The nice thing about the parts manuals is that they provide you with not only the description and part number but in this case the actual measurements of the seals.

AC-33703-A 7/8" ID x 1-1/8" OD x 1/8" thick
AC-33697-A 13/16" ID x 1-1/16" OD x 1/8" thick

I was lucky in that a Early For V-8 club member gave me the name of a local supplier for seals that has been in business since 1965. I took the dimensions down to them the they had the correct seals but in the "Loaded" design.

Resealing a PS unit already in the car.

Jack up the car and put it on stands (safety first) then turn the steering all the way to the right. The pictures used her show the unit with the wheels straight. If you turn the wheels all the way to the right it makes the unit and hoses more accessible. You will need to disconnect the 4 hoses from the valve body. (Picture below). Obviously this will serve to drain your system.

Then remove the end cap screws and end cap. (Picture)

Next remove the nut on the end of the shaft. (Picture)

Now remove the two bolts on the back of the valve body. (Picture with arrows)

Now slip the valve body off the shaft, and remove the seals at both ends of the shaft. Lower right hand portion of the picture shows the shaft removed from the valve body. (Picture below). This picture was taken when the entire system was out of the car being rebuilt.

Take time to clean all the parts thoroughly. I coated the seals with Dow Corning 111 prior the installation to allow for ease of installation. I have used this previously with success when rebuilding the power brake unit.

Now reassemble in the reverse order.

My local seal supplier is Rocket seals of Denver: http://rocketseals.com/
Seal #: PN-12500875 and PN-12500812. Now for the good part. The NOS seals normally sell for around $25.00 each and up plus shipping. The cost of these are $4.33 each.

I also replaced the seal between the lid and the body of the reservoir. The part number is 8-737 and the cost is $2.49.

Since you have drained the reservoir you might want to replace the filter . It is a Hastings HF-783. Rather than paying for shipping to can get the filter at:
CarQuest # 85653
NAPA # 1653
O'Reillys # 51652 (WIX)

To date not a drop on the floor.Hope this helps.

Note: This same PS system was used in my wife's 1970 Cougar XR-7. Not sure just how long this system (power cylinder) was used by Ford. So the information can be used for more than just 52'-53'.

[Merc Cruzer]

The O'Reilly's number should be 51653 (WIX)

[Merc Cruzer]

A better look at the old seals

[KULTULZ]

- THAT WAS A DAMN GOOD WRITE-UP -

THANK YOU merc cruiser !!!

[Merc Cruzer]

My pleasure. Let me know if I can help further.

[38 coupe]

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I have a friend with a 53 Mercury two door sedan with half of a power steering conversion done. I'll send him this thread. Many thanks!