FAQ for 7xx/9xx/90 Cars
Steering Fluid Cleanliness. I keep inside the power steering fluid
reservoir a small but VERY STRONG magnet. I lowered it down inside on a
wire and because it is strong it attaches to the metal bracket holding
the reservoir. After first two weeks I was cleaning it every second or
third day and you would be surprised how many metallic particles it was
able to take out. For the first week the magnet was all covered and black
every time. Now my power steering fluid is so clean, that I can see the
bottom of the container with a flash light. Of course I changed the fluid
after I take most metallic particles out. Besides there was a bulletin
issued by Volvo stating that inside PS container there should be a magnet.
Steering Fluid Change. [Tip] If you want to drain the system,
loosen the fittings at the steering rack, from the pump & reservoir,
let all the fluid drain out, then refill system with Volvo steering fluid,
or Dexron. Auto trans fluid will aerate more than the steering fluid,
so you will get less steering wheel chatter, when you start the engine
& drive the car. Fill the reservoir, then start the engine.
When the pump empties the reservoir, then refill it.
[Another Procedure: Query:] My power steering
fluid looks pretty bad. What's the best way to replace it - without disassembling
the entire system? [Response 1: Steve Ringlee] The return hose to the p/s
reservoir is the top hose. Disconnect this at the reservoir (see Editor's
Note below) . Using a small piece of solid pipe, clamps and some clear
vinyl tubing, make an extension that will direct the fluid into a container
or bucket. Get a quart of new fluid (I use Mobil 1 synthetic ATF, which
works fine even though your manual calls for Type F.) Start the car and
have a friend cycle the steering wheel back and forth. As the pump moves
the old fluid out the hose, refill the reservoir with new fluid. When you've
just about used up the quart, you will have completely flushed out the
old fluid. Re-connect everything, bring the reservoir up to level and you
are back in business. If you suspect metal contamination in the old fluid,
place a strong magnet on a thin wire into the reservoir and leave it there
for a week, removing it to check it and clean it off. [Response 2:
Jerry Andersch] One other bit of advice. Be careful not to be overly aggressive
in removing the return line to the plastic P/S reservoir. Lines that have
never been removed can be tough to free up. Resorting to yanking, twisting,
and swearing can result in a unexpected trip to the wrecking yard to find
a replacement reservoir. Easy does it and save yourself some grief.
[Editor's Note:] The return line is VERY TOUGH to remove because
of an aggressive barb at the end of the outlet pipe. Be prepared to cut
about one inch of hose, enough to peel it off the reservoir, so make sure
you have a little extra hose you can pull up from the pump. To make
life easier next time, file off the sharp edge of the barb to make the
hose removable. [Response 3: Gary DeFrancesco] In my car, the oil
was never changed by the PO, and it was black. Be prepared to dump in more
than a quart of new ATF while flushing. The flow rate through the pump
surprised me, even at idle. I went through 2 quarts of oil as fast as I
could dump it in. And I mean DUMP. Have a friend or spouse start the engine
and turn the wheel lock to lock. I found it best to do this with the front
wheels off the ground. Have your partner start turning the wheel as soon
as the engine starts since it will not take too long to go through the
Gear Rack Power Steering Fluid Bleeding Procedure. [TSB courtesy
of Alldata] Volvo: Bleeding Cam Gear - Power Steering Racks
The Cam gear power steering (p/s) rack
has shown an increased sensitivity to the bleeding method used to remove
air from the system. Described below is a bleeding procedure that
introduces fluid at a sufficiently low rate so that fluid foaming is minimized.
Failure to follow this method can result in air retention in the fluid
which could result in steering wheel pulsation under certain driving conditions
until the air is purged from the system.
After installing the steering rack in the
vehicle, continue with the following additional steps:
1. Connect all fluid and mounting hardware,
but do not attach tie rod ends. Top up fluid level in p/s reservoir and
maintain throughout the bleeding procedure. Do not start engine at this
2. With engine off, purge system of air
by turning steering wheel full left to full right at relatively low speed
until air bubbles do notappear in the reservoir.
3. Turn wheel to full lock, for instance
full right, and hold in this position until air bubbles stop appearing
in the reservoir. Be patient. This can take up to five minutes. Turn wheel
to full opposite lock, full left in this case, and let air bubble out as
4. Remove fuel pump fuse to prevent the
engine from starting. Crank engine and turn steering wheel simultaneously
full left to full right slowly until bubbles stop appearing in reservoir.
Note: Do not crank engine for more than 30 seconds at a time.
5. Install fuel pump fuse, start engine
and let idle. Turn steering full left to right slowly until air bubbles
stop appearing in the reservoir. If the steering continues to pulse or
vibrate, continue bleeding by rotating the steering wheel full left to
right until vibrations diminish.
6. Reconnect tie rod ends and adjust toe-in
to specifications. Check for leaks and proper fluid level.
Note: If the system is filled too quickly,
the fluid can be prone to retaining air. Once this occurs, it can take
one to two days of normal driving before the air is released from the system.
Column U-Joint Noise. [Symptom:] I have a 89 740t with an annoying
steering wheel problem. When I turn the steering wheel more than 1/4 of
a turn a single loud click is heard (and felt only very slightly) and then
repeated again at random points while completing the turn and then returning
it back to center. Lock to lock you can hear it click six to seven times
in all. It seems to get louder when the cars not at rest. The rest of the
steering feels tight. The sounds are emitting from right behind the steering
wheel where the turn signals levers are located.
[Another Related Query:] My steering is
very stiff at centre and anywhere 90 degrees from centre. If I am at a
point at 90 degrees from centre, or at centre, it will loosen up a allow
a little play. This makes cornering very jagged. The same thing happened
last year, not as bad, but went away as suddenly as it came. It's a soft
stiffness, like a tight bearing feel, not a definite notch. I would like
to fix this soon before I break something from forcing it.
[Diagnosis:] You may have a U-joint in
the steering column that is seizing due to drying of the lubricant and
corrosion. Does the noise occur every 180 degrees when you turn from lock
to lock? That is a pretty good indication of a u-joint problem. Try spraying
some penetrating oil on the U-joints every day for a week. To isolate which
joint is the problem, you could start out by spraying one joint each day
for a week and if nothing happens do the other joint the next week. If
the situation improves, then apply a heavier lubricant, but something thin
enough to soak into the bearing of the u-joint. If it does turn out to
be a faulty joint, you could always replace it, but that would cost money
and/or time. After two weeks, if nothing improves, follow up the Volvo
technical service bulletin lead.
[Response 2: Brian Oliver] Sounds like
one of the U-joints in the steering intermediate (just above the steering
rack) shaft is seizing. Give them a good spray of molyslip
grease or something (not WD-40!) to see if this frees it up. Then you will
know if this was the problem by whether you solved it or not. Unfortunately
you will likely have to replace the damaged parts sooner or later, probably
more sooner than later, if you are left with a lot of play in the steering.
You don't want this worn to the point of breaking.
Steering Wheel and Column. [Query:] The steering column seems
to be very slightly loose on occasions when cranking the wheel. If I shake
the wheel vigorously to the left and right, it appears the whole assembly,
including the ignition switch, moves independent of the dash board. I expected
to find two bolts clamping the column up against the dash structure, but
couldn't see anything. [Response: John Kaiser] Pull lower valance
(under steering wheel). Check for loose bolts on support beam(black metal
runs right to left. You may want someone to shake wheel while you take
a good look. Not usually a 740 problem except on high mileage cars.
Steering Pump Failing? [Query:] Problem: power steering
pump seems to be failing, 1988 740GLE, 190k miles. Symptoms: Squeeling
power steering pump during harder corners at low RPM's (under 1200 RPM)
and at start-up for about a minute. Power steering assistance sometimes
intermittent during slow cornering when the wheel is more than 30 degrees
off-center. Power steering
fluid blackened, as if contaminated with
heavily used engine oil or carbon soot, but levels have not dropped at
all over the past month. Help Needed: Other possible causes, recommended
solutions, sources/pricing for the power steering pump (any aftermarket
pumps out there? should I go new/rebuilt?), and any special notes on the
actual removal/install process. Also considering draining and replacing
the fluid to see the effect on the system -- any feedback on this?
[Response: Ross Gunn]
This may be stating the obvious, but is
the belt in good shape (not glazed) and tight? Suspected Culprits:
bad seals within the pumping mechanism itself, possibly abuse by my fiancee
as she tends to sometimes be willing to bring the wheel to full turn-lock
for tight corners (grrrrr... that eats up pumps in many brands of cars).
Suspect that idiot at fast-change oil place may have used non-suitable
fluid to top off the reservoir, causing the contamination (the fluid was
a healthy, robust clean red/burgundy two months ago, as it had been since
I owned the car). Black would usually be from seals in the rack (sorry
if I spoiled your
day). I don't believe there are any o-ring
type seals in the pump moving parts. Try stirring a small powerful magnet
through the reservoir to see if there are steel particles in the fluid.
If none, then the discolouration is probably seal material. If there are
steel particles, this is an indication of pump breakdown.
Definitely change the fluid before investing
time and money on a new pump - empty the reservoir and refill with clean
fluid, turn wheels lock to lock with the pump running, shut off engine,
repeat about 5 times. This may seem a bit mickey mouse, but is a
lot easier than disconnecting the fluid lines at the rack to drain the
If, after fluid replacement, the steering
is still poor, you might try adding some power steering anti leak fluid.
This material softens the seals and if the problem is due to leaking seals
within the rack, it may give them a lease on life - perhaps not a permanent
cure, but may be worth a try. Add a small quantity (2 ounces perhaps) and
drive for a couple of weeks, if no change, or insufficient improvement,
Power Steering. As some may remember, I have had a problem with the
power steering on my '90 745 GLE (steering heavy, particularly in colder
weather). It was of only a little comfort to know that I was not alone.
There has been some discussion about what to do with this, (change fluid,
add anti-leak additive, etc.) but no clear fix was mentioned other than
replacing the rack. In my continuing effort to exhaust all possibilities,
before taking a step as drastic as replacing the rack, I disassembled the
pump control valve to see if there were any obvious faults. There were
none, so I decided to make a little seat of the pants improvement. In order
to increase the pressure output of the pump, I stretched the spring of
the control valve. Originally 5cm long, it is now 5.5 cm long. The result
is more power assist making the steering act more like I believe it should
have all along. It will be interesting to see what happens when the weather
The service manual gives a procedure for
checking the pump pressure, but since I did not have the fittings and gauge,
I took this trial and error approach:
Technical details: my pump is the Saginaw
TC type as used on 760/740 diesels 1987-, 4 cyl E and carb 1985-mid 87,
4 cyl F, FT & ET 1985-, 16 valve B204/234 1988- and 780 diesel 1985-.
The control valve on this pump is reasonably easy to get at without removing
the pump from the car. It is under the pump outlet fitting. If anyone is
tempted to try this fix, be careful stretching the spring, because if you
over stretch it, you can't compress it back again. Use a graduated procedure
whereby you try stretching it a little and check the length, then if not
long enough, stretch it a little harder and so on until you get the desired
length. It is interesting to note that "later versions (don't know what
years specifically) of this pump have a higher pressure than earlier and
other current variants and produce a greater steering force during parking,
etc." (Quoted from Volvo service manual.) The Saginaw TC pump has the remote
plastic reservoir mounted on the left inner fender. There are also ZF pumps
(carb and E engines without turbo 87-), and Saginaw P pumps with a round
(6 cyl B28/280 1982-mid '84 or oval (6 cyl mid '84-, 760/740 diesel '82-86,
4 cyl F, FT, ET, E and carb '82-'84) reservoir. These are the type pumps
that are housed inside the reservoir. All have a Control valve, but the
reservoir of the P pumps must be removed to gain access to it. The ZF pump
control valve may be accessible without removing the pump from the car,
but I cannot be sure.
If you are having similar problems and
feel adventurous, undertake this modification procedure at your own risk.
All I can say is that so far the system is working well. Note that I also
have a minor balance problem with steering being a little heavier to the
right than the left. This is not severe enough to be a problem when driving
and as far as I can see, there is no balance adjustment possible on this
rack. The service manual simply says to replace or recondition the rack
if balance exceeds limits. Without the test gauge, I cannot determine whether
mine is within limits or not. I guess the next step should be a wheel alignment
to be sure misalignment is not a factor.
Identification. See the diagrams below to identify your power
steering rack as either a CAM or Z-F. Illustrations copyright RPR,
used by permission.
For rebuilt racks, see also Source
of Rebuilt Power Steering Racks.
Maintenance FAQ for 7xx/9xx/90 Cars
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