F250 power steering wimping at low speed, low rpm. Replace, rebuild, ingore?

Hi. I have an '89 F250 4wd diesel extended cab truck with 60K miles.
Yah, low miles. It sat a lot before I got it! Great truck if there's
lots of turning room.

Lately the steering at low speed has become very difficult. The power
steering seems to disappear and the steering wheel jerks. Bad stuff in
traffic!

So I'm debating whether to rebuild the power steering pump ($15) or
replace the pump ($60 for a rebuilt pump). Also, I've read that the
filter must be changed ($5) and that the pump usually goes bad due to
debris from decomposing power steering lines, ergo replace them, too.
Of course, I read this on an auto-parts website, so I'm asking you:

what parts should be replaced? Any advantage to buying a rebuit pump
over rebuilding it myself? Should I replace the lines, too?

Thanks!

On 1 Jan 2005 08:56:11 -0800, "Gonzo"
> wrote:

>Hi. I have an '89 F250 4wd diesel extended cab truck with 60K miles.
>Yah, low miles. It sat a lot before I got it! Great truck if there's
>lots of turning room.
>
>Lately the steering at low speed has become very difficult. The power
>steering seems to disappear and the steering wheel jerks. Bad stuff in
>traffic!
>
>So I'm debating whether to rebuild the power steering pump ($15) or
>replace the pump ($60 for a rebuilt pump). Also, I've read that the
>filter must be changed ($5) and that the pump usually goes bad due to
>debris from decomposing power steering lines, ergo replace them, too.
>Of course, I read this on an auto-parts website, so I'm asking you:
>
>what parts should be replaced? Any advantage to buying a rebuit pump
>over rebuilding it myself? Should I replace the lines, too?
>
>Thanks!

Just for the fun of it, I would put a white paint spot on the belt and
a white paint spot on the power steering pump pulley, right next to
each other. After driving, I would put it in idle, and see if the
dots are still lining up with each other.

But, that doesn't *fix* anything. I would do it to see if the belt is
slipping. If the belt needs to be replaced, buying a new pump isn't
the cure, unless the pump pulley bearing is defective.

Lg

>>>Just for the fun of it, I would put a white paint spot on the belt
and
a white paint spot on the power steering pump pulley, right next to
each other. After driving, I would put it in idle, and see if the
dots are still lining up with each other.<<<

Your kidding, right? Assuming a 2 pulley system, and both pulleys are
the same diameter (an incredible unlikelyhood), your distance between
pulley centers would have to be [(Pulley Circumference * (N - 1)] / 2
where N = a natural number > 1 --- for the marks to realign in N
turns of the P/S pump pulley. What would be the point in the real
world, where cars need to be fixed?

The OP is willing to rebuild a P/S pump. On that info I will assume he
can tell if a belt is loose or slipping -- atleast with the
encouragement of "Hey, make sure the belt isn't slipping before you
diagnose any further!"

Now for useful help... Domestic pumps do wear out and lose pressure
frequently enough to consider it a good possibility in your case. But
you mentioned the steering wheel jerks. If it's powering itself back
and forth against your will then you may have a bad valve in the
steering gear. In either case its not worth saving a few bucks doing
the overhaul yourself. Especially with the low cost of remans and the
special fasteners and preload collars you may run into. I sometimes
recommend RESEALING pumps and gears for cost savings -- but you have a
functional problem that may require internal parts.

Toyota MDT in MO

On 1 Jan 2005 12:03:35 -0800, "Comboverfish" >
wrote:

>>>>Just for the fun of it, I would put a white paint spot on the belt
>and
>a white paint spot on the power steering pump pulley, right next to
>each other. After driving, I would put it in idle, and see if the
>dots are still lining up with each other.<<<
>
>Your kidding, right?

ehm, no. Every so many revolutions of the belt, should the white
spots line up with eachother again? Or are they going to be separated
FOREVER ?

at engine rpm, 750 at idle, how long , how many revolutions of the
belt would it take for the marks to hit spot on with eachother. IOW,
what is the period of the synchronization cycle.

Depends, but if you STAND THERE with a high intensity flashlight, I
suspect that sometime before Easter you will see the marks flash
together at least ONCE !

> Assuming a 2 pulley system, and both pulleys are
>the same diameter (an incredible unlikelyhood), your distance between
>pulley centers would have to be [(Pulley Circumference * (N - 1)] / 2
>where N = a natural number > 1 --- for the marks to realign in N
>turns of the P/S pump pulley. What would be the point in the real
>world, where cars need to be fixed?

The point in the real world is to try to find a way to see if the
bearing is seizing on the ps pump, and allowing the belt to slip over
it, thus causing symptoms OP described. Do you know a better way to
do this ? Let's hear about it.

>The OP is willing to rebuild a P/S pump. On that info I will assume he
>can tell if a belt is loose or slipping -- atleast with the
>encouragement of "Hey, make sure the belt isn't slipping before you
>diagnose any further!"
>
>Now for useful help...

Thank God you're here to save the day.

> Domestic pumps do wear out and lose pressure
>frequently enough to consider it a good possibility in your case. But
>you mentioned the steering wheel jerks. If it's powering itself back
>and forth against your will then you may have a bad valve in the
>steering gear. In either case its not worth saving a few bucks doing
>the overhaul yourself. Especially with the low cost of remans and the
>special fasteners and preload collars you may run into. I sometimes
>recommend RESEALING pumps and gears for cost savings -- but you have a
>functional problem that may require internal parts.
>
>Toyota MDT in MO

On 1 Jan 2005 12:03:35 -0800, "Comboverfish" >
wrote:

BTW, if you use a stopwatch, with a *lap* feature, you will know
EXACTLY when the spots are supposed to hit eachother. Then measure
the differences between lap times to see if they're all the same.

Too simple? Than spend $1,000 on some dumbass machine to figure it
out.

Check the belt first, make sure it's tight, your symptoms sound like
that is the culprit. Just did a deisel with hydro boost (brake assist
provided hydraulically via the P.S. pump) power brakes that turned hard
when the brakes were applied & the pump was the problem. If you have
the tools to rebuild it yourself, your cheaper off but for $65 I'd save
the hassle, bolt it on, have a nice day. Good luck.

Lawrence Glickman,
I'm not going to reply to you any more than to point out one more time
that your advice here is foolish. This is only in the interest of the
OP. I chose to respond to Gonzo's question because it sounds like he's
willing to take advice and fix his own car. I respond to the people I
think would actually benefit from my experience as an honest tech
working in the real world. It makes me feel good to help; not to hurt
or mislead.

SO, again, marking the belt and pulley on a real car (God forbid it's a
serpentine belt) will result in so VERY many revolutions before they
realign that its quite pointless to expect any useful diagnosis to come
of it. There is such a thing as normal slippage,
stretching/contracting, and expansion/flexing of components in the real
world. A lap time comparison? With the average engine fluctuating at
least 50 RPMs? And a diesel?? How do you know when the pulley is
locking up??? How about -- it would stop. How about -- remove the belt
and feel the bearing smoothness while turning it. These are normal
methods when the aforementioned "Look at it with your eyes and listen
to it with your ears" methods don't prove a slipping belt. How about
-- I feel the OP has the common sense and willingness to check the
basics after a simple reminder of "check the basics"?

Sorry, Gonzo. I'm new to reading these boards. Just started about the
time Google changed to its new BETA format. But in a short time its
become apparent that many people, some helpful and some smartasses,
have argued with LG to no avail. He seems like a troll, but unlike
trolls he appears to post initial replies in the nature of helpfulness.
Its just that they are often so far off base from helpfulness that it
really grates on my nerves. Then he is such a jackass when someone
points out his error or even just posts a different view without
reference to his remark.
Anyway, good luck with your Ford.

Toyota MDT in MO

On 1 Jan 2005 14:31:34 -0800, "Comboverfish" >
wrote:

>Lawrence Glickman,
>I'm not going to reply to you any more than to point out one more time
>that your advice here is foolish. This is only in the interest of the
>OP. I chose to respond to Gonzo's question because it sounds like he's
>willing to take advice and fix his own car. I respond to the people I
>think would actually benefit from my experience as an honest tech
>working in the real world. It makes me feel good to help; not to hurt
>or mislead.
>
>SO, again, marking the belt and pulley on a real car (God forbid it's a
>serpentine belt) will result in so VERY many revolutions before they
>realign that its quite pointless to expect any useful diagnosis to come
>of it. There is such a thing as normal slippage,
>stretching/contracting, and expansion/flexing of components in the real
>world. A lap time comparison? With the average engine fluctuating at
>least 50 RPMs? And a diesel?? How do you know when the pulley is
>locking up??? How about -- it would stop. How about -- remove the belt
>and feel the bearing smoothness while turning it. These are normal
>methods when the aforementioned "Look at it with your eyes and listen
>to it with your ears" methods don't prove a slipping belt. How about
>-- I feel the OP has the common sense and willingness to check the
>basics after a simple reminder of "check the basics"?
>
>Sorry, Gonzo. I'm new to reading these boards. Just started about the
>time Google changed to its new BETA format. But in a short time its
>become apparent that many people, some helpful and some smartasses,
>have argued with LG to no avail. He seems like a troll, but unlike
>trolls he appears to post initial replies in the nature of helpfulness.
>Its just that they are often so far off base from helpfulness that it
>really grates on my nerves. Then he is such a jackass when someone
>points out his error or even just posts a different view without
>reference to his remark.
>Anyway, good luck with your Ford.
>
>Toyota MDT in MO

Well said, God's Gift to Humanity. Well Said !

I do have an impulse to help, although sometimes I may miss the mark,
do not condemn me for any sincere effort(s) to ease the burden of
others.

I am an _overqualified_ electronics technician. In fact, at Panasonic
Factory Automation I was promoted to Engineer Status. That isn't an
opinion of yours, that is a matter of record.

So don't pat yourself on your back to hard for being a good fellow,
your arm might fall off.

Lg

Hi, Comboverfish. Thanks for the useful and coherent info.

Yah, I know to check belts, thanks. Sealing the pump seems redundant
in that it isn't leaking. Unless the seal you refer to somehow
improves pump pressure?

Replacing the filter seems like a no-brainer...its cheap and effective
preventive maintenance. How about replacing the pressure lines as a
source of whatever causes pump failure? That isn't cheap. I've done a
visual, and the outside of the lines look fine, but obviously I can't
look inside them without destroying them! Should I plan on that
expense?

If the gears have a bad valve, wouldn't that show up at high speed as
well? Also, the jerking is symmetric (both left and right-hand
turns)...would the gear's valves decay symmetrically? And isn't that a
big pain in the wrench to replace?

Thanks for the info! Its good to have some idea what I'm up against
before whipping out the tools...

>Sealing the pump seems redundantin that it isn't leaking. Unless the
seal you refer to somehow
>improves pump pressure?

What I said was that I only recommend resealing pumps and gears (if
they leak), not rebuilding them for the sake of fixing a performance
problem. You have a performance problem of some sort, therefore it is
not my recommendation to rebuild. Get a reman.

>Replacing the filter seems like a no-brainer

I'm not sure what filter you speak of - I know of aftermarket suppliers
suggesting or supplying an inline filter to be installed during a P/S
component replacement. Maybe your diesel has one already... I don't
get to see any diesel anythings at my shop or at home (thankfully!).
Sure, put one on or replace the one you have for $5. Sounds like money
well spent.

>If the gears have a bad valve, wouldn't that show up at high speed as
well?

The torsion control valve system in a P/S gearbox reacts to deflection
when the input shaft is turned before the inertia of the control valve
have a chance to move. It can deflect from a left turn or a right turn
equally well. The more resistance it meets with (ie. slow speed
turning in a parking lot) the more fluid it redirects to assist the
steering linkage in the correct direction. What I'm getting at is that
you require less assist (sometimes none) at highway speeds but around a
sharp corner or in your driveway that pump is giving the steering gear
all it can handle.

The control valve can fail just about any way though its really
uncommon for one to go bad. It was just a possible suggestion. A
steering gear replacement is a good sized job - figure on renting or
buying a pitman arm puller to remove the steering linkage.

But I would make sure you can tell the difference between a dropout in
power assist and the additional unwanted assist of a bad gear. Maybe
have someone else drive it for a second opinion. A drop in assist
could be the aforementioned slipping belt (if its tight and dry and
looks good it should be ok) or pump cavitation (low on fluid, air
getting in system) but probably not a 'bad' pump. Pumps
characteristically leak or weaken slowly over time or fail all at once.
They don't wildly cycle back and forth between functional and broken.
Toyota MDT in MO