In the really cold weather below 20 degrees the steering pump on my 280ZX would squeal for mercy for a while until the car warmed up. Now that the weather is on the right side of the freezing mark, the pump is silent as normal.
I've never changed the pump or the fluid. The belt is fairly new.
Is this a case of "If it ain't broke, don't fix it"?
Do you think I should replace the fluid in the pump, or leave it alone just accepting that the noise is a sign that the pump will probably fail in a the not too distant future?
Thanks for your advice!

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1980 280ZX 2+2
2003 350z Touring
2005 350Z Touring - Silverstone Gray
CT plate PHILSZ

Squealing "pumps" are usually actually slipping belts. If you hear it 'squeal', it's probably not the pump. If you hear it 'moan' and 'whirr', that's probably the pump.

Belts slip for several reasons.
1. Most commonly they are simply loose and can be tightened (A LITTLE) to remove the squeal.
2. Sometimes the belt is a little old or worn or stretched, which lets it slip.
3. Other times you might spill a bit of fluid on them which causes them to slip until centrifugal force throws enough fluid off to let the belt get a good grip again.
4. If the car sits unstarted for many weeks, a belt might take a shape which takes it awhile to lose once you start diving the car again.
5. Cold weather can cause the belt to become stiff or brittle, and unwilling to 'be round' upon demand. Just as your tires can develop temporary 'flat spots' by sitting too long in one place during cold weather, your belts can temporarily become inflexible for awhile, too.

Because this is such a common problem, the aftermarket demons have created dozens of 'cures' which *guarantee* to make your belts silent. In my opinion they are little more than 'snake oil' and don't do anything except make you think you've cured the problem, when a change in temperature or a tighter belt would have done the same thing. You could spend $11 on a spray can of 'belt dressing' which would evaporate as soon as it left the can nozzle, and when the warmer temperatures (either outside or under the hood) make the squeak go away, you could pat yrslf on the back for having 'fixed the problem'.

Back in the Day they actually sold bars of soap which you were expected to hold against a turning engine belt to silence it . Probably the most-dangerous thing I can think of doing, today. It's a wonder any of us still have fingers.

Field-testing your pump is easy. With the engine running, turn your wheels full-lock left and right. If your pump moans or shudders at full lock, or if it sings a loud symphony with highs and lows as you spin the wheel, you can suspect something is amiss in the pump. It never hurts to change out your power steering fluid if it has turned colors to a darker shade, either.

I think you're right ~ it ain't broke.

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1970 240Z

+1 on the belt idea.

Have tightened my alternator belt twice since changing the timing belt. Turned it enough to not squeak in the summer months and yesterday I turned it considerable more so it would stop squealing in the cold months as well.

FWIW.

The danger lies in tightening it too much, which puts excessive side-pressure against your water pump bearing. You must maintain that 1" 'thumb dip' in the middle of the belt (on my 240 ~ your 'dip' might vary) in order to prevent premature bearing failure. I've done it wrong in years past and killed my pump.

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1970 240Z

Thank-you for taking the time to offer your good advice, Frank. I'll re-check the belt tension, but suspect that it's just fine and the extreme cold was the culprit. No point over-tightening, as you say.
The fluid is as old as the car and dark in color. I'm tempted to change it, but the workshop manual does not indicate how to drain the old fluid out. I've heard of some people using a turkey baster! Do you know the correct procedure? Am I just asking for unnecessary trouble by getting air into the system?

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1980 280ZX 2+2
2003 350z Touring
2005 350Z Touring - Silverstone Gray
CT plate PHILSZ

I have used the same turkey baster since 1974. Get one of your own or buy your wife a new one ~ she won't want it back after you've used it on your car. Get a plastic one, not a glass tube.

I know it sounds stupid, but it's only stupid if it doesn't work!

Just a word of caution ~ keep rags all around the pump and have a receptacle/container right down near the pump as you pull fluid out of it. In other words, take as many precautions as you can to ensure you don't spill that power steering fluid on anything in your engine bay. It does incredible things to painted surfaces and if you get it on any hot surface, it smokes like you wouldn't believe. Once spilled, it's really hard to clean up. Make the trip with the loaded turkey baster to the receptacle/container as short as possible, to limit the threat of dribbling on your paint. And squirt the dirty fluid out of the baster GENTLY so it doesn't splash. Intelligent people would warn you to wear eye protection and gloves.
You won't be able to change ALL the fluid unless you unhook a lower hose and drain it out (not recommended for amateurs). Settle for changing the majority of it and changing the color a few shades lighter. I never had any problems with air bubbles in the line, since the recirculating pump design sort of eliminates them naturally.

I've used my baster to change brake and clutch fluid on my Z several times over the years. I've never changed the power steering fluid on a Z, but I have done it on almost every other vehicle I've ever owned ~ Pontiacs, Buicks, Chryslers, Dodges, Chevys, and about 7 Fords. The turkey baster comes in handy for a lot of other jobs, too ~ if you ever owned a 289 or 302 V8 Ford, you're familiar with the little pool of oil which magically "grows" at the base of the distributor. The baster is the instant solution to that problem, and for removing any pooled soapy water which collects in your intake manifold when you steam-clean or pressure wash your engine. It really should be a permanent part of your toolbox.

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1970 240Z

Just undo a pressure line underneath, drain into bucket with car running, keep adding fluid till fluid looks good coming out. I prefer to use ATF Also if belt is a hair tight, could be why when it's cold.