Kubota M6060HFC, 2019, AC compressor sqealing...

[gleaner63]

Greetings All,

I have a 2019 purchased brand new Kubota M6060HFC with 190 hours; when I crank it up and enable AC button, AC appears to cool and run normally. However, when I increase the engine RPM, about half throttle, a high pitched "squeal" appears to come from near AC compressor/belt area. I had my wife stand outside and look at it, and the clutch appears to be sticking, or not spinning entirely free. Of course I'm guessing, but is it a good guess that the compressor clutch is in the process of failing and a new compressor is the best option? Many thanks for any or all replies...

-Clarence

 

[JimmyJazz]

Perhaps the belt is improperly adjusted. Many years ago aerosol hair spray was occasionally applied to shrieking automobile fan belts to "fix" them. Might be worth a try. Good luck.

 

[gleaner63]

Perhaps the belt is improperly adjusted. Many years ago aerosol hair spray was occasionally applied to shrieking automobile fan belts to "fix" them. Might be worth a try. Good luck.

Thanks and I will give that a try; sure beats the heck out of a 15 -1700 dollar fix given by the dealer.....

 

[Motion]

When squealing have you tried turing the A/C off to see if it stops? If it does then as other have said it may be the belt which may need to be readjusted (most new belts will have an inital stretch). Check your WSM to see how to adjust.

 

[gleaner63]

When squealing have you tried turing the A/C off to see if it stops? If it does then as other have said it may be the belt which may need to be readjusted (most new belts will have an inital stretch). Check your WSM to see how to adjust.

Yes, when I turn the AC off the squeal stops......will check my WSM I purchased on ebay....

 

[Dave_eng]

Here is the belt tension page from the factory WSM.
Before doing any expensive repair I would replace the belt.
If the original belt has been slipping re tensioning may not fix it.
Dave

 

[hagrid]

Have you checked the accessory drive belt tension?

 

[troverman]

For what its worth, my L4060 HSTC had 360 hours on it with no A/C problems and no belt adjustments. I would definitely start with replacing the belt. Those Kubota A/C compressors are extremely expensive for some reason. They are also very small.

 

[gleaner63]

Great news fellows: swapped out and re-tensioned fan belt and that corrected the issue. Appeared the old belt was stretched, so replaced with new one just in case there were other issues with it......all of the tips here are much appreciated....

 

[Dustyx2]

I had to tighten the belt on my M7060 at around 100 hours to stop it squealing so probably not an uncommon thing.

 

[Tx Jim]

IMHO AC/fan belt routing on my M7040 leaves some to be desired as the belt doesn't have very much pully surface contact for good belt gripping.

 

[BAP]

AC compressor belts for any model or make needs to be very tight to keep from slipping. AC is the highest load of any belt driven accessory.

 

[Nicolangu]

Do you have a good understanding of how compressors work? That awful squeal could be due to air leakage. Air mass can squeal nastily where the rubber gasket is. By the way, I don't understand why you need to know my location in the UK. If you're interested, I can tell you. I live in a hamlet near Newport. By the way, I now notice the author's post about replacing the fan belts in the #9 reply. I'm glad he solved his problem. I had that problem too, but it was caused specifically by the compressor gasket tension. My friend then brought a lot of pneumatic tools to fix the problem. I don't think I'd have done it myself with a broken arm back then.

 

[Fedup]

Do you have a good understanding of how compressors work? That awful squeal could be due to an air leak. Air mass can make a nasty squeal where the rubber gasket is.

Maybe you could explain a little about how that applies here?

 

[JP_Austin]

Kubota settled on solid adjusters to maintain tension. Most automotive belts use spring loaded or hydraulic tensioners that tend to self adjust. The old school solid adjustment is simple but not necessarily maintenance free. Glad to hear it quieted up.

Only downside to this method of tension is if you get a bit agressive you can easily over tension a belt and ruin a idler or accessory bearing in a hurry. Follow the tension guidelines closely or you can over do it.

 

[mcmxi]

Do you have a good understanding of how compressors work? That awful squeal could be due to an air leak. Air mass can make a nasty squeal where the rubber gasket is.

I guess you missed post #9 where the OP provides an update.

On a friendlier note, where are you from/located in the UK?

 

[mcmxi]

Kubota settled on solid adjusters to maintain tension. Most automotive belts use spring loaded or hydraulic tensioners that tend to self adjust. The old school solid adjustment is simple but not necessarily maintenance free. Glad to hear it quieted up.

Only downside to this method of tension is if you get a bit agressive you can easily over tension a belt and ruin a idler or accessory bearing in a hurry. Follow the tension guidelines closely or you can over do it.

I've had a '98 Jeep TJ for more than 22 years and it has solid adjusters for belt tension. I bought an OTC belt tension gauge a few years ago which kind of helps. I would agree that the spring loaded tensioners of today are more user friendly, but it's not like the old way (found on our tractors) is a poor design. I do think that belts are all over the map in terms of quality. Some seem to stretch quickly, others, particulary the factory belts that are often quite a bit more expensive seem to do better.

I had to adjust the belt tension on my first MX6000 fairly soon after receiving it. There was a weird "squelch" sound coming from the belt that went away with a bit more tension. I haven't had a problem with the second MX6000 or M6060 yet.