Odd problem with PS/alt on 93 Corolla

My wife is temporarily driving an ol' 93 Corolla and just noticed a
strange problem: Particularly when cold, if she turns a corner [I've
only seen it turning sharp right], the battery light comes on and
doesn't clear until the wheels straighten. The steering also becomes
much stiffer.

My working theory is that when hard over, the PS pump gets harder to
turn, and the belt driving the alt and PS pump slips. I looked at the
belts and they seem OK to me.

However there are two problems with this theory: one, I can't see if
the same belt drives both accessories, and two, I would think the PS
pump is under _minimum_ strain when the wheel is hard over (since the
relief valve operates).

Is this symptom most likely to be a belt or idler/tensioner pulley, the
PS pump, or the alternator? That area of the car is pretty noisy, any
of those parts could be complaining.

"larwe" <zwsdotcom@gmail.com> wrote in message
news:1164659778.490922.215160@14g2000cws.googlegroups.com...[color=blue]
> My wife is temporarily driving an ol' 93 Corolla and just noticed a
> strange problem: Particularly when cold, if she turns a corner [I've
> only seen it turning sharp right], the battery light comes on and
> doesn't clear until the wheels straighten. The steering also becomes
> much stiffer.
>
> My working theory is that when hard over, the PS pump gets harder to
> turn, and the belt driving the alt and PS pump slips. I looked at the
> belts and they seem OK to me.
>
> However there are two problems with this theory: one, I can't see if
> the same belt drives both accessories, and two, I would think the PS
> pump is under _minimum_ strain when the wheel is hard over (since the
> relief valve operates).
>[/color]

Look at the number of accessory drive belts on the front of the engine (the
front of the engine is on the right hand side of the car from the passenger
compartment perspective). If there is only 1 accessory drive belt, then it
is driving the alternator, power steering pump, and AC compressor. If there
are 2 accessory drive belts, then see if one is powering just the AC
compressor.

When the steering wheel is turned all the way to the stop, the relief valve
does open but the pump is still working very hard.

When checking the condition of the accessory drive belts, check the ribbed
underside to make sure it is not glazed or has chunks missing from the ribs.
Also make sure that the belt is properly tensioned.
--

Ray O
(correct punctuation to reply)

[color=blue]
> Is this symptom most likely to be a belt or idler/tensioner pulley, the
> PS pump, or the alternator? That area of the car is pretty noisy, any
> of those parts could be complaining.
>[/color]

On 27 Nov 2006 12:36:18 -0800, "larwe" <zwsdotcom@gmail.com> wrote:
[color=blue]
>My wife is temporarily driving an ol' 93 Corolla and just noticed a
>strange problem: Particularly when cold, if she turns a corner [I've
>only seen it turning sharp right], the battery light comes on and
>doesn't clear until the wheels straighten. The steering also becomes
>much stiffer.
>
>My working theory is that when hard over, the PS pump gets harder to
>turn, and the belt driving the alt and PS pump slips. I looked at the
>belts and they seem OK to me.
>
>However there are two problems with this theory: one, I can't see if
>the same belt drives both accessories, and two, I would think the PS
>pump is under _minimum_ strain when the wheel is hard over (since the
>relief valve operates).
>
>Is this symptom most likely to be a belt or idler/tensioner pulley, the
>PS pump, or the alternator? That area of the car is pretty noisy, any
>of those parts could be complaining.[/color]

It's a 14 year old car - when was the last time you changed the fan
belt singular (serpentine) or belts plural (old school V-belts)? It
is (or they are) probably overdue to be changed, and are glazed and
slipping.

If it still acts up with a fresh belt and it's a one-belt multi-rib
serpentine system, the spring in the automatic tensioner takeup pulley
may be bad and it's not getting the belt tight enough. Or you don't
have the tension set properly on a car that does it by hand.

The relief valve pops on the PS pump at hard-lock, but it is still
working at maximum output - the pressure has to go high enough to pop
the relief, and that only throttles the system pressure back 50 PSI or
so while it's bypassing. The relief valve doesn't close again until
you ease off on the steering wheel, and the system pressure drops down
to the normal unloaded state.

When your hands are off the wheel is when the system is at minimum
pressure. The spool valve in the steering box is bypassing the fluid
right back to the pump, and keeping the pressure low.

--<< Bruce >>--

Bruce L. Bergman wrote:
[color=blue][color=green]
> >My wife is temporarily driving an ol' 93 Corolla and just noticed a[/color]
>
> It's a 14 year old car - when was the last time you changed the fan[/color]

Good question, and I have no idea, since it's not actually _our_ car
(though we've been offered it for free if we want it). I suspect the
answer is "last time it broke". Visually, the belts [there are at least
two] seem OK and the tensions is about what I'd expect.
[color=blue]
> When your hands are off the wheel is when the system is at minimum
> pressure. The spool valve in the steering box is bypassing the fluid
> right back to the pump, and keeping the pressure low.[/color]

Thanks. I was visualizing the system differently.

Ray O wrote:
[color=blue][color=green]
> > However there are two problems with this theory: one, I can't see if
> > the same belt drives both accessories, and two, I would think the PS[/color]
>
> Look at the number of accessory drive belts on the front of the engine (the
> front of the engine is on the right hand side of the car from the passenger
> compartment perspective). If there is only 1 accessory drive belt, then it
> is driving the alternator, power steering pump, and AC compressor. If there
> are 2 accessory drive belts, then see if one is powering just the AC
> compressor.[/color]

There are at least two belts, but it's a bit difficult to see which one
goes where. I'll have a closer look this weekend.
[color=blue]
> When checking the condition of the accessory drive belts, check the ribbed
> underside to make sure it is not glazed or has chunks missing from the ribs.
> Also make sure that the belt is properly tensioned.[/color]

By ribs you mean what I would call teeth?

larwe wrote:[color=blue]
> My working theory is that when hard over, the PS pump gets harder to
> turn, and the belt driving the alt and PS pump slips.[/color]
========
You should be able to get an inexpensive click type belt tension gauge
at NAPA to check belt tension.
You might be surprised to see how far they can be off when actually
checked.
Correct tension is in the manual:
[url]http://oregonstate.edu/~tongt/camry/index.html[/url]
-------------------
I bought the Burroughs belt tension gauge on eBay and every time I
check it is difficult for me to believe that the correct belt tension
on the Camry is 120 pounds - seems awfully tight, but I've found that
figure listed in three different places in the Factory Service Manual
and also checked the calibration of the gauge - it is correct. My guess
is that the belt when loose vibrates a lot between the pulleys actually
accelerating bearing wear, whereas when correctly tensioned, as the
engine revs increase the belt stays straight.
This isn't really a factor with the short power steering belt, but the
principle is the same. With the factory belt, used, it had to go all
the way to the end of the adjustment slot to get the correct tension -
eighty pounds IIRC.

"larwe" <zwsdotcom@gmail.com> wrote in message
news:1164720743.487062.67750@n67g2000cwd.googlegroups.com...[color=blue]
>
> Ray O wrote:
>[color=green][color=darkred]
>> > However there are two problems with this theory: one, I can't see if
>> > the same belt drives both accessories, and two, I would think the PS[/color]
>>
>> Look at the number of accessory drive belts on the front of the engine
>> (the
>> front of the engine is on the right hand side of the car from the
>> passenger
>> compartment perspective). If there is only 1 accessory drive belt, then
>> it
>> is driving the alternator, power steering pump, and AC compressor. If
>> there
>> are 2 accessory drive belts, then see if one is powering just the AC
>> compressor.[/color]
>
> There are at least two belts, but it's a bit difficult to see which one
> goes where. I'll have a closer look this weekend.
>[color=green]
>> When checking the condition of the accessory drive belts, check the
>> ribbed
>> underside to make sure it is not glazed or has chunks missing from the
>> ribs.
>> Also make sure that the belt is properly tensioned.[/color]
>
> By ribs you mean what I would call teeth?
>[/color]

There are 3 types of rubber belts used in automotive applications. The type
most people probably are familiar with is called a V-belt, and if you were
to cut the belt and look at the end, the profile looks roughly like a V with
a flat top and bottom, or an inverted pyramid with the pointy end cut off.
The sides of the belt should fit tightly with the inner sides of the pulley,
and that contact is what drives the accessories.

The second type of belt is called a ribbed belt, and if you cut the belt and
looked at the end, you would see a series of grooves or ribs on the
under-side of the belt, almost like treads on a tire that mate with grooves
in the pulleys, and it is the groove - to - groove contact that drives the
accessories. A ribbed belt is usually used for serpentine belts, where 1
long belt drives everything on the front of the engine.

The third type of belt is a cogged or toothed belt, most often used for
timing belts. The teeth in the belt fit in teeth in pulleys to provide
precise timing and do not allow for any slippage.

This link [url]http://www.bandousa.com/html/automotive.html[/url] has pictures of the
types of belts, from left - to - right, V-belt, a cogged V-belt (a cross
between a V-belt and a toothed belt), a ribbed-belt, and a toothed belt.
--

Ray O
(correct punctuation to reply)

In article <bc245$456c6a67$44a4a10d$12486@msgid.meganewsservers.com>
rokigawaATtristarassociatesDOTcom "Ray O" writes:
[color=blue]
> [...] or an inverted pyramid with the pointy end cut off. [...][/color]

ISTR our geometrical friends call that a "frustum of a pyramid".
Inverted, as you say. Something to do with zombie languages[*].
:-)

[* : my coining -- "dead" languages that won't stay dead]
--
Andrew Stephenson

"Andrew Stephenson" <ames@deltrak.demon.co.uk> wrote in message
news:1164749844snz@deltrak.demon.co.uk...[color=blue]
> In article <bc245$456c6a67$44a4a10d$12486@msgid.meganewsservers.com>
> rokigawaATtristarassociatesDOTcom "Ray O" writes:
>[color=green]
>> [...] or an inverted pyramid with the pointy end cut off. [...][/color]
>
> ISTR our geometrical friends call that a "frustum of a pyramid".
> Inverted, as you say. Something to do with zombie languages[*].
> :-)
>
> [* : my coining -- "dead" languages that won't stay dead]
> --
> Andrew Stephenson
>[/color]

You must have a phenomenal memory to remember a term like "frustom"

OTOH, I can barely keep my children and pets' names straight. When it is
time to call them, it is Caseymarktigermatthewsarahshadowgizzie.
--

Ray O
(correct punctuation to reply)

In article <1fe11$456cb675$44a4a10d$14441@msgid.meganewsservers.com>
rokigawaATtristarassociatesDOTcom "Ray O" writes:
[color=blue]
> "Andrew Stephenson" <ames@deltrak.demon.co.uk> wrote in message
> news:1164749844snz@deltrak.demon.co.uk...[color=green]
> > In article <bc245$456c6a67$44a4a10d$12486@msgid.meganewsservers.com>
> > rokigawaATtristarassociatesDOTcom "Ray O" writes:
> >[color=darkred]
> >> [...] or an inverted pyramid with the pointy end cut off. [...][/color]
> >
> > ISTR our geometrical friends call that a "frustum of a pyramid".
> > Inverted, as you say. Something to do with zombie languages[*].
> > :-)
> >
> > [* : my coining -- "dead" languages that won't stay dead][/color]
>
> You must have a phenomenal memory to remember a term like
> "frustom"[/color]

*heh* Partly the oddity of the word, partly my memory being a
bit like flypaper -- it picks up the intellectual counterparts
of dead insects. FWIW for decades I actually misremembered it
as "frustrum", only fixing it as "frustum" on checking for the
post cited above. (Yes, I check such facts. Sad, wot? <g>)
[color=blue]
> OTOH, I can barely keep my children and pets' names straight.
> When it is time to call them, it is
> Caseymarktigermatthewsarahshadowgizzie.[/color]

Good idea: use the same name for all. Like car makers who tag
a long series of different models with the same monicker.
--
Andrew Stephenson

"Andrew Stephenson" <ames@deltrak.demon.co.uk> wrote in message
news:1164766280snz@deltrak.demon.co.uk...[color=blue]
> In article <1fe11$456cb675$44a4a10d$14441@msgid.meganewsservers.com>
> rokigawaATtristarassociatesDOTcom "Ray O" writes:
>[color=green]
>> "Andrew Stephenson" <ames@deltrak.demon.co.uk> wrote in message
>> news:1164749844snz@deltrak.demon.co.uk...[color=darkred]
>> > In article <bc245$456c6a67$44a4a10d$12486@msgid.meganewsservers.com>
>> > rokigawaATtristarassociatesDOTcom "Ray O" writes:
>> >
>> >> [...] or an inverted pyramid with the pointy end cut off. [...]
>> >
>> > ISTR our geometrical friends call that a "frustum of a pyramid".
>> > Inverted, as you say. Something to do with zombie languages[*].
>> > :-)
>> >
>> > [* : my coining -- "dead" languages that won't stay dead][/color]
>>
>> You must have a phenomenal memory to remember a term like
>> "frustom"[/color]
>
> *heh* Partly the oddity of the word, partly my memory being a
> bit like flypaper -- it picks up the intellectual counterparts
> of dead insects. FWIW for decades I actually misremembered it
> as "frustrum", only fixing it as "frustum" on checking for the
> post cited above. (Yes, I check such facts. Sad, wot? <g>)[/color]

I agree with Sherlock Holmes' hypothesis that the human brain has a finite
capacity, and I'm afraid I've reached capacity with obscure tidbits about
mechanical devices. I still can't remember the difference between a bogie
and an eagle and a hook and a slice.
[color=blue]
>[color=green]
>> OTOH, I can barely keep my children and pets' names straight.
>> When it is time to call them, it is
>> Caseymarktigermatthewsarahshadowgizzie.[/color]
>
> Good idea: use the same name for all. Like car makers who tag
> a long series of different models with the same monicker.
> --
> Andrew Stephenson
>[/color]

LOL! How true!
--

Ray O
(correct punctuation to reply)