940 power steering belt squeal

[940torslander]

Hi
Recently purchased my 940 LPT Torslanda - it had noticeable belt squeal at full lock which the previous owner says had been apparent for some time. It seemed to get worse (approx 3 weeks later) and steering became v heavy at low speeds - so I have taken into my local garage on the assumption that the PS pump and/or belt was giving up the ghost.

The garage reported a very loose belt which appeared to be due to re-routing to bypass the aircon (assumed seized - not checked). Having adjusted this, it did not resolve the situation - indeed it seemed to make it worse. So the theory about re-routing may be a red herring

I have now tracked down a power steering pump (currently on its way from Germany) which is hopefully the correct part, but the issue likely remains that the belt may not be correct if it has indeed been re-routed.
Is anybody familiar with all of this such that you can suggest a solution? Are 940 air con condensers still available? Any help whatsoever would be appreciated.

As a supplementary query, can anybody recommend an 'old volvo specialist' in the NW of england (I'm in Chester)

Thanks, Jon

[Forrest]

On the 940 with factory-fit aircon there are three separate belts. The rearmost one is crankshaft, power-steering pump and water pump. The next one is crankshaft and alternator and the final one (nearest the front) is crankshaft and aircon compressor. It would not have been necessary to do anything other than remove the front-most belt to isolate the aircon compressor. Even this would have been unnecessary unless the magnetic clutch in the compressor had failed in a mysterious way since even with the aircon belt in situ all it would do is turn the compressor pulley if the system were turned off and/or low on refrigerant.

The Volvo belts you need are:

Power Steering 981680 (formerly 973488)
Alternator 973487

If you are using non-OEM belts that may well be the problem as there are slight variations in profile and width.

Assuming you have the correct belts, check for obvious wobble or incorrect alignment. Bushes failing can cause this, but so could the non-standard routing you allude to.

I have also found that very dirty or incorrect fluid levels can lead to power steering noise. More pump noise than belt noise but worth checking.

After years of trying all sorts of methods to get belt tension right the method I have found most effective is to adjust the belts until you can flip the longest clear run by 90 degrees but no more. I'm not sure quite how the result compares to Volvo's recommendations but it seems to work for me. It is safer to have a belt too loose rather than too tight as the latter will eventually damage bearings.

New aircon compressors are NLA according to the Skandix website. However, the (Zexel) compressors are usually robust and long-lasting. Are you sure it is the compressor that's the problem? It's usually pipework or condenser leaks that put paid to Volvo aircon systems. If the compressor is bad what are the symptoms? Have you checked its operation yourself? Have you checked the clutch gap? Are you getting voltage both sides of the low-pressure sensor near the receiver/drier? Does the system contain the right amount of the right refrigerant?

[Rversteeg]

There is a lot of confusion about the correct V-belts.
On the last series 940s the PAS pump shares the V-belt with the water pump; the alternator has its own belt, just as the AC.
All belts should be 11,9 mm wide, except the belt for the AC which is 13 mm.

For the PAS / water pump: if equipped with a turbo the best V-belt is 11.9 x 1000 mm length, for a non-turbo version 11.9 x 1013.
The alternator belt is slightly longer (if Bosch); 11.9 x 1013 mm.
A 1000 mm belt is less common, so often a 1013 mm is used, but this can give issues with the maximum adjustment range of the PAS.

A turbo version has a slightly smaller waterpump pulley diameter, to have a higher pump speed and increased cooling water flow. This explains the shorter belt for a turbo engine.

Before changing any pump or compressor I would first check whether the correct belts have been used. Any squeeking on full lock is no issue, but is should be tight enough to convey the power during normal steering.

Rob

[Tyron760]

Originally Posted by Rversteeg

A turbo version has a slightly smaller waterpump pulley diameter, to have a higher pump speed and increased cooling water flow. This explains the shorter belt for a turbo engine.

Rob

Thanks Rob, I did not know that!

[gpl1968]

I was told once that a possible problem is the alloy bracket holding the p/s pump onto the engine block. The hole supporting the long bolt becomes worn and the p/s pulley stops being parallel with the others. I did buy new brackets for mine but it's still on my to do list. The attached pdf might help.

Belts are a problem. I've bought belts from main dealers in the past, using the VIN for reference and found them to be the wrong size. The only way to tell in my experience is to measure what's on your car.
This is what I use in my 940 (B230FK with A/C):
20200621_145336 by Gavin Liddiard, on Flickr

There is a good Volvo specialist in Connah's Quay: www.deesidemotorcentre.co.uk.
I went there once with a friend who was buying a V70 and they had an immaculate 244 in the showroom.

For parts , Ryebrook on Sealand Road (parts and servicing are behind in the estate) are quite helpful and oem parts prices are surprisingly competitive for these older cars.

[baggy798]

Originally Posted by Rversteeg

A turbo version has a slightly smaller waterpump pulley diameter, to have a higher pump speed and increased cooling water flow. This explains the shorter belt for a turbo engine.

That would result in a slower pump speed? Like an underdrive smaller pulley on the crank. Reduced water cavitation at higher rpm apparently.