CHANGING YOUR POWER STEERING FLUID by Martin Bokesch
One of the most annoying sounds coming from under the hood of the Turbo Coupe, and most Ford vehicles for that matter is the whine of the Power steering system. Although some sound is normal, and associated with the operation of the steering system, as age creeps up on these units, the sounds tend to get louder.
The most overlooked service on the T/C’s is replacing the Power Steering Fluid and Brake Fluids. We all are probably very conciencious about the proper and timely service of Engine, Transmission and Differential oils, but tend to overlook the power steering system. A sure sign that service is due, is a silver discoloration of what would normally be clear/clean Steering Fluid. A high concentration of silver particles is the sign of metal wear in the system. Further into the Flushing procedure I will explain h a quick check to determine the source of the metal.
A
brief description of the system used on the T/C’s
The steering system is
comprised of plastic reservoir mounted fore of the drivers side shock tower.
Conveniently next to the starter solenoid. The reservoir is connected to the
power steering pump with the supply line. The smaller line returning from the
steering gear is the return line to the reservoir.
The steering pump itself is
the Ford model CII and was commonly used on the ThunderBird, Cougar, Mark VII
and Mustang of our cars era. The pump itself is commonly referred to as a vane
hydraulic pump, comprised of a Nylon reservoir body attached to an Aluminum pump
housing. From the pump, the pressure line is comprised of a swivel style outlet
fitting on the hose, and is meant to allow swivel movement on the hose to pump.
This is normal and does not indicate a loose fitting. If there is leakage at
this point, or the hose actually pulls out of the pump body, there is a repair
kit available from Ford that allows for the replacement of the swivel seal and
retaining ring. Instructions for installation are normally included in the
repair kit.
The pump supplies oil to
the Integral Power Rack and Pinion Steering Gear. The ThunderBird T/C is
supplied with a 15:1 constant ratio gear, and was an option of the handling
package. Normal Ford steering R&P’s were 20:1 variable ratios, and are
basically the same in physical dimensions. The difference lies in the rack teeth
and control valve assembly, both internal. The rack and pinion assembly consists
of a one piece, cast aluminum housing. The gear design also incorporates quick
style fittings for the pressure and return lines, which allow the fittings to
swivel. The internals consist of a one-piece rack/piston assembly and rotary
control valve to direct oil flow as required to move the piston, in turn causing
the wheels to turn. The return oil line is connected to a one piece steel line,
that is mounted in front of the radiator to assist in cooling the return oil
before it is returned to the plastic reservoir tank.
The above description is
brief, and in know way covers all the items in the pump or Rack and pinion that
effect the steering gear and its performance. It is just meant to be an overview
of the system in general.
Tools and materials
required are minimal.
1)
Good
screwdriver (or a ¼ drive socket set)
2)
At least
a one-gallon jug to collect the purged oil. Preferably clean, to inspect the
collected used oil.(Plastic Milk
jug works for me)
3)
1 gallon
of Ford Type F or Equivalent ATF. (I have found that for flushing, cheap works
just fine)
4)
A remote
starter switch is a nice touch (or patient Wife or friend to spin the engine
over)
5)
Some time
and a nice sunny day, or a warm shop!
---
A) Disconnect the Coil wire
and raise the front wheels off the ground. Securely block the car up; do not
rely on the jacks to hold it in place. Connect the remote starter switch if
available.(or connect your Wife, Friend, Kid in the drivers seat)
B) Disconnect the return
line hose clamp at the reservoir. A screwdriver will do, ¼ drive is a bit less
likely to slip, but not required. Plug
the return line port on the reservoir.
C) Direct the return line
from the cooler line into your collection jug. I have found that tying the line
to the collection jug stops the line from jumping out of the jug as you do this.
D) Ensure that the
reservoir is filled to the top with ATF. Without touching the steering wheel at
this time, turn the car over with the ignition switch until you note the fluid
level dropping. Leave the cap off the reservoir, and it is easy to see the oil
level drop. Just keep adding fresh oil as it goes down; do
not let the reservoir run dry. This might take a bit of practice at
first!
E) The easy part, just keep
topping the reservoir up and spin the engine over until the fluid returning to
the collection jug runs clean.
F) While continuing to add
oil, turn the engine over while turning the steering wheel from side to side to
purge the old oil from the rack and pinion. Again, continue until the oil runs
out clean.
G) If the oil is clean,
hook the return line back up, top up the steering reservoir to the proper level,
connect the coil wire. Lower the car to the ground so the front tires have a
load on them. Start the car up and spin the wheel from side to side 3 to 4
times, slowly, and try not to bottom the system out, (go to end of the stroke
and sit there!!) Check the reservoir again, note that there should be no air
bubbles in the oil (foamy or white looking oil). If this happens, ensure the oil
is to the right level, and repeat the process. Some foaming/whiteness is normal
and will dissipate in a few days; usually just over night will allow the air to
escape.
H)
That’s it, oil's done.
Just
a few additional tips/reminders.
1) The oil that was
collected can be run through a clean rag to filter out the material that was in
your oil. From this, you can do a quick check on the material gathered to see
what you have. With a magnet of any kind, sweep over the material you have
collected. Anything sticking to the magnet indicates steel and can only come
from the steering pump. Although the rack and pinion does have a steel piston
assembly, it runs in aluminum and the steel will not wear. If you have silver
metal in the material that a magnet will not pick up, it is aluminum. This can
come from the rack and pinion, usually the first source, and the pump body,
usually the second and least likely source. Do not be alarmed by aluminum in the
findings, as this is quite normal and unless it is large quantities, does not
mean that something is worn out, it just means it is wearing. (Similar to
cleaning an Auto Tranny pan!!)
Unless you have had a
complete failure, other items will be of little interest and could comprise of
bits of plastic from the sealing material, dirt in general and other things that
tend to find there way into your oil systems. Most of this will be too fine to
recognize, regardless. If the pieces are large enough to see and recognize, some
additional repairs are in order.
2) I have never required
more than 1 gallon of ATF to do the flush and top the system off. I buy the same
oil that I run in my trans and if there is any left over, I have a home for it.
If your system is extremely dirty, it may take more, if it is very clean, why
bother doing it!!!
3) VERY IMPORTANT. When you are flushing the system out, take great care to keep the
fluid level up as much as possible, not letting the pump run dry, so as not to
introduce to much air into the system. A few seconds of no oil in the pump will
not hurt the pump. Air just cause’s the same old moans and howls to appear.
4) I have done this
procedure on many units a number of times and now can do it with the engine
idling and with assistance on the steering wheel turns, never allow the pump to
run out of oil. Same hoses and theory, just have the front of the car off the
ground, stand by with the oil and when the car starts, the oil will begin to
drop immediately. You will have to begin to add oil at once, and you can also
begin to turn the steering from side to side, slowly, almost immediately also.
Have your assistant turn the engine off as you get close the end of your
available fluid, as to not run the pump out of oil.
5) Ford
recommends Ford ATF. I use true power steering oil;
hydraulic formulated, as the viscosity I prefer and the additive packages are
more conducive to lubrication and long life. I have never added and type of
Additive or friction modifier, but this is one place that it may be worth trying
it in, as there is nothing that can be harmed by trying it.
Boost
High, Fly Low(-:
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