Volvo KAD 43 failure

foxgoose

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Worrying failure on my five year old, 400hrs, just serviced, KAD 43 coming back from Torbay to Dartmouth last night.

Compressor idler pulley seized, disintegrated and threw the belt.

It's a cheap plastic pulley with a "sealed for life" (hollow laugh) bearing with no way of lubricating or protecting it.

Since it was only the compressor we got home - but now i'm worried 'cos there's an identical idler on the water pump belt, which would be a disastrous failure on a single engined boat.

The pulley assembly looks as if it would be more at home on a cheap lawn mower than a marine diesel.

Anybody else had similar problems with these?
 

gjgm

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supposedly one of the problems with the older volvos, is the multiple belts- its quite easy to get the tightnening wrong on one which then puts strain on another. If the second one is a minor bearing-in engineering terms- then the risk of failure increases. Wonder if they fiddled with the belts at that recent service?
 

ians

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foxgoose

I had a few failures on the old type (allen key Types) kept repacing them at 200 hrs.
ended up upgrading to the kad43 type, I have replaced all of these at about 300 hours as the bearings in 2 of them were not sounding good, so replaced them all.

Ian
 

spannerman

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There is a modified idler pulley kit available for these engines due to failures, check with your local VP dealer
 

msimms

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On one of our engines this was picked up during pre-purchase. Surprisingly, though the pulley had completely seized the belt had survived. The belt had worn a flat on the plastic of the pulley almost all the way through to the inner metal part of the pulley.

This was only being used at river speeds, I doubt the belt would have survived for long at planing speeds. This engine also had a new water pump fitted at the same time, not sure if that was related but I guess the moisture in that area would be increased with a leaky pump. Hours at that time were in the 230 region.
 

Dave_Snelson

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I was wondering about VP mods until I read spannermans reply. Could you also go to a light engineering firm and have a couple turned with correct size quality bearing interference fitted? Good thing about small engineering companies is that they do good work at reasonable rates coz they don't know what you want it for (i.e. marine use!) /forums/images/graemlins/smile.gif
 

JohnRob

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Learned last year that KAD300s do the same. What a mess the shredded rubber makes of the engine room! Good idea, Spannerman - I'll check to see if same upgrade is available for KAD300.

ItS
 

alt

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Only belt i've had a problem with on my KAD32 is the circulation belt. Understandable, it drives the alt, servo and supercharger. It was almost about to snap and was making a creeping noise to changed it in time.

However I couldn't help but notice more 'powder' on top of the rocker cover. I suspect it's the circulation belt. Either way to be safe, all belts on my KAD32 will be getting changed anually, with spares on board. It's an expense, but has to be done imho
 

Peanuts

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You are spot on about the circulation belt because it does drive every-thing. I always remove the belts annually, checking for cracking and general wear, however I go to autofactors to purchase new ones if required, do you have the auto part numbers?

Steve
 

alt

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I do not but would greatly appreciate the KAD32 ones if you have them /forums/images/graemlins/wink.gif

Are they Volvo (ie. from a Volvo dealership) or spurious ones from a motorfactor?

[ QUOTE ]
You are spot on about the circulation belt because it does drive every-thing. I always remove the belts annually, checking for cracking and general wear, however I go to autofactors to purchase new ones if required, do you have the auto part numbers?

Steve

[/ QUOTE ]
 

Col

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I made my own pulleys so that I don't have to run the tensioners tight. Takes all the load off the tensioners.

23072007246.jpg
 

Col

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Still use a tensioner, but it isn't very tight and is more like an Idler. It's the loading on the tensioner bearings that kill them. With my pulleys there is positive drive without the need for the belts to be done up "bar tight". Also means the belts last longer and less belt dust.
 

alt

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Makes sense now - Just remembered that the KAD pulley's don't have teeth, unlike your custom ones. Great idea

[ QUOTE ]
Still use a tensioner, but it isn't very tight and is more like an Idler. It's the loading on the tensioner bearings that kill them. With my pulleys there is positive drive without the need for the belts to be done up "bar tight". Also means the belts last longer and less belt dust.

[/ QUOTE ]
 

DavidJ

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[ QUOTE ]
Makes sense now

[/ QUOTE ]

Not to me!. Surely the tension is to ensure that sufficient 'drive' is given to the compressor when it kicks in. If the tension is set below the recommended limit then there is a risk of poor drive, poor compressor performance and increased belt slip/wear.
 

Col

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Look at the photos again. They are toothed pulleys so belt has positive engagement like a chain.
 

alt

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I've not had any problems with my KAD32 (Touch wood) but how much did it cost to get those made up?
 
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