My 1957 Factory Service Manual advises to use "Type A" automatic
transmission fluid in the power steering. That's the same as recommended
for the transmission. However, that stuff is long ago unavailable, and
Don Verity advised me to use "Type F" ATF in the original Torqueflite
transmission he rebuilt for my 300C. Therefore, we put the same "Type F"
fluid in the power steering reservoir (after sucking out all we could of
whatever had been in there for at least the last 48 years since my father
bought the car in 1968). Now the power steering seems to work just fine
- doesn't squeak or leak. I think there's a strong chance that a modern,
dedicated "power steering fluid" might not be compatible with all the soft
goods in the system, including seals and hoses, possibly leading to
significant leakage. Not only that, but the "new stuff" might not have
the lubricity characteristics required for the metallurgy and clearances in
the 57+ -year-old mechanism, possibly leading to aggravated wear and possible
It might be analogous to the situation with using modern low-zinc oils in
the engine, whereas the engines of the era were designed to use an oil with
higher concentrations of zinc and phosphorus, which was standard for the time
frame. Using the new low-zinc oils (mandated by the cursed EPA in 2007!)
can cause premature wear (and outright failure) of our good old flat-tappet
lifters and cams.
Las Cruces, New Mexico 1957 Chrysler 300C convertible S/N
Just curious...why would one power steering fluid be
better than another ? I thought they are all the same.
Hi Ron & 300 Club Members:
A few years ago I did research on power steering fluid for my 300C
At one point some one recommended that I talk to a Chrysler Rep so
made more phone calls and got a good one. He recommended
power steering fluid for our older cars and I was able to find it at
Auto Supply in Sheboygan, Wisconsin. With confidence, I
product and have been using it ever since. Unfortunately I do not
a paper trail or email trail about the subject.