L6060 Air Conditioning Clutch Not Engaging (somewhat random at this point)

[bmr1963]

The air conditioner clutch recently stopped engaging and needless to say the cab got hot. I turned the tractor off for a couple of hours and when I restarted it the air once again worked and stayed working for two hours (remainder of day) when I put it back in the shed. Got it out a couple of days later and it never cooled down as the compressor clutch was never engaged.

I searched the internet for likely causes as I want to rule out low freon as when it started working it kept working for two hours to the point the cab actually got cold and I had to turn the air control warmer.

I think I am looking for an electric issue based on the fact it worked, it didn't and once again did. I plan to change out the solenoid under the roof top that sends power to the magnetic switch tonight and if that don't work I will attempt to find and short the low pressure switch to see if that causes the clutch to engage. If that don't work it appears that I mgiht be able to send 12 volts to the clutch just to see if I can make the clutch engage. After that I guess it's heading toward the dealer.

Anyone had any issues with the air on the L Series Grand? If so what were the symptoms and what was the fix?

 

[DustyRusty]

Changing parts is not diagnosing the cause. If you understand the electrical circuit, get out the test light and diagnose the problem. It could be a clogged evaporator and condenser, or both that is causing high pressures and there might be a circuit that disconnects power to the the compressor. You will also need a schematic of the refrigerant system. Every time people start swapping out parts to attempt to resolve a problem the more difficult it becomes for the technician to establish cause and effect. When I learn that someone has changed components in an attempt to resolve a problem, I will not work on the unit. You should start by using Simple Green Foaming coil cleaner and get the coils clean.

 

[bmr1963]

Changing parts is not diagnosing the cause. If you understand the electrical circuit, get out the test light and diagnose the problem. It could be a clogged evaporator and condenser, or both that is causing high pressures and there might be a circuit that disconnects power to the the compressor. You will also need a schematic of the refrigerant system. Every time people start swapping out parts to attempt to resolve a problem the more difficult it becomes for the technician to establish cause and effect. When I learn that someone has changed components in an attempt to resolve a problem, I will not work on the unit. You should start by using Simple Green Foaming coil cleaner and get the coils clean.

Thanks for the reply but looking for someone who had experienced an issue with the clutch not engaging which is part of the diagnosis. Had the tractor quit cooling and not started back cooling again I would be looking toward the compressor, low freon or something mechanical. Currently I am looking at the electrical by seeing if the relay is sending power to the clutch and the easiest ($16) way is to unplug a relay and replace it with a new relay knowing that if it starts working it may not be the fix but rather the tractor deciding to once again engage the clutch and cool. Air flow is not the issue as the clutch is not engaging. I do need assistance if anyone has the electrical knowledge of what wire/voltage causes the clutch to engage as reverting back to the old pressure switches from the 70's I used a paper clip to cause the compressor clutch to engage to allow me to add freon 12 back in the day it was .99 cents a can and no one knew that we even had an ozone layer. I made a visit to talk to the local service manager only to find out that this will be his first rodeo on electrical on the L series as other than adding freon a time or two the L series air conditioning seems to be solid. Anyone with the electrical schematic of the air circuit would be a great help as I haven't been able to locate it online other than a small drawing that has the relay I plan to change in roof accessign from the top.

 

[DustyRusty]

You can test the relay with a 12-volt test light and probe. There is no need to replace a relay to determine if the original one is good or not.
Likely the compressor has a high-pressure and a low-pressure switch in line with the compressor's positive wire. The old compressor (GM R6) compressor has a switch at the rear that interrupts the circuit when there are low freon levels. The systems I am familiar with have the high-pressure switch on one of the hose line fittings. I suggested cleaning the condenser and evaporator coils because they can get clogged up with dirt and debris from use in dusty conditions and blowing them out doesn't allow for free flow of cooling air. Cleaning the system is a must before you take any pressure readings without being misled by the erroneous results.

 

[Lug66]

I’d be willing to bet that the service technician would throw on a trusty set of Freon gages instead of relying on someone else’s Magic 8 ball. It sure sounds like the low or high pressure pneumatic switch is doing its intended function.

 

[bmr1963]

Thanks for the timely replies and info. Just identified the issue and the compressor clutch was getting fire however it wasn’t pulling in. That removed the pressure switches and relays that I expected. The clutch was out of tolerance as was more than .025 that book shows. I was able to tighten it by building a compression bolt from all thread 6mm by 1.0 and getting it back within tolerance. It’s working now and may have to put a clutch on later however tractor only has 800 hours so should have life left. Thanks again for the feedback. Air would work until the tractor got hot and once it cooled down it would work again

 

[GrizBota]

Good fixing. So the air gap was 25 thousands over spec? I wonder how it would grow that much without some major wear on the clutch surfaces, which shouldn’t be slipping while in contact. If the magnetic coil is a bit weak, and it’s always been 25 out of spec, I wonder if that would explain it?

Just tonight I pulled apart an electric A/C clutch (Toyota, not Kubota L) and it looked like there was lapping compound between the magnetic coil and the surrounding pulley portion of the clutch. And it did make some unhappy noises. New clutch and it’s all better now. Unfortunately my professional mechanic did not diagnose the failure properly and fouled up $600 in parts not getting it fixed right the first time, due to lacking attention to detail and slamming it in missing both c clips for the compressor shaft.

 

[GreensvilleJay]

re: 'professional' mechanic.... someone that can make mistakes and cost you even MORE money.

 

[GeoHorn]

Unfortunately, many “professional mechanics” are merely parts-replacers. Eventually they’ll get the real offending part replaced…. and the owner gets the invoice.

 

[bmr1963]

Good fixing. So the air gap was 25 thousands over spec? I wonder how it would grow that much without some major wear on the clutch surfaces, which shouldn’t be slipping while in contact. If the magnetic coil is a bit weak, and it’s always been 25 out of spec, I wonder if that would explain it?

Just tonight I pulled apart an electric A/C clutch (Toyota, not Kubota L) and it looked like there was lapping compound between the magnetic coil and the surrounding pulley portion of the clutch. And it did make some unhappy noises. New clutch and it’s all better now. Unfortunately my professional mechanic did not diagnose the failure properly and fouled up $600 in parts not getting it fixed right the first time, due to lacking attention to detail and slamming it in missing both c clips for the compressor shaft.

No I didn't explain the gap correctly. What I found was the range for the gap was .012 - .025 The .025 guage dropped in and was loose however I didn't put multilple gauges together and get the exact gap before I started tightening. Sorry for the confusion.

 

[bmr1963]

Unfortunately, many “professional mechanics” are merely parts-replacers. Eventually they’ll get the real offending part replaced…. and the owner gets the invoice.

I actually went to the local dealership yesterday morning to see about getting it fixed "professionally" only to find out that other than adding freon a few times they really didn't have the shop knowledge from prior jobs to fix it. I spent the rest of the day researching looking for information and stumbled on the manual that proved to be very helpful.

https://kubotabooks.com/AutoIndex/index.php?dir=Tractor%20Owners%20Manuals/&file=L3560%20to%20L6060%20WSM.pdf

 

[bmr1963]

Good fixing. So the air gap was 25 thousands over spec? I wonder how it would grow that much without some major wear on the clutch surfaces, which shouldn’t be slipping while in contact. If the magnetic coil is a bit weak, and it’s always been 25 out of spec, I wonder if that would explain it?

Just tonight I pulled apart an electric A/C clutch (Toyota, not Kubota L) and it looked like there was lapping compound between the magnetic coil and the surrounding pulley portion of the clutch. And it did make some unhappy noises. New clutch and it’s all better now. Unfortunately my professional mechanic did not diagnose the failure properly and fouled up $600 in parts not getting it fixed right the first time, due to lacking attention to detail and slamming it in missing both c clips for the compressor shaft.

There may be some excessive wear due to slippage from the past few years however I really don't know when and how it got out of tolerance. It may have been off from the factory. At this point I have identified the issue and now will be looking for a new clutch source should I need it down the road. The local dealer indicated that they never just swap the clutch but change out the whole compressor. Needless to say I will at least attempt to salvage what I have a save several bucks should a new clutch be necessary down the road. For now it is working and I was extremely fortunate that the work was done in my shop.

 

[bmr1963]

I’d be willing to bet that the service technician would throw on a trusty set of Freon gages instead of relying on someone else’s Magic 8 ball. It sure sounds like the low or high pressure pneumatic switch is doing its intended function.

I have a set of old trusty gauges however without the compressor kicking in I really didn't know what they would tell me. I was going back to the 70's looking to short across the low pressure switch to make it kick in and to my surprise when I finally was able to disconnect the connection at the compressor with damaging it I found that I had 12 volt going to the clutch. I pecked it with the tractor off and heard it click. I then start the tractor and found me a wooden rod and gave it a tap and it kicked in. I then went back to the manual and found the tolerance of .025 and the gauge dropped in without touching. I never measured what the gap was however it was way out of tolerance and spent the next two hours trying to figure out how to build a tool to tighen it.

Anyone with knowledge of the location of the switches would be helpful for future issues. I found what I called the high pressure switch, located on the smaller line telling me it was the high pressure switch under the roof at the back corner near the air filter intake going toward the blower housing. There's a threaded plug on the compressor itself with two wires going into it that I thought might be the low pressure switch due to the proximately of the clutch wire power. Thank goodness I had power going to the clutch as I really never had to get into the electrical on my fix last night.

 

[DustyRusty]

If you can determine the brand of the compressor a clutch might be available. Sometimes it isn't easy to replace just the clutch since the old one needs to have a puller to remove it and the new one needs a special installer to push it back on. The tool to install it screws into a recess on the compressor shaft and the other part of the tool will push it onto the shaft. I have the tool for the Delco R-6 compressors and sometimes it isn't the easiest thing to get to work properly. If you don't get it right the first time you will damage the front seal, and that is why the dealers will only replace a compressor, not repair one.

 

[eserv]

Thanks for the timely replies and info. Just identified the issue and the compressor clutch was getting fire however it wasn’t pulling in. That removed the pressure switches and relays that I expected. The clutch was out of tolerance as was more than .025 that book shows. I was able to tighten it by building a compression bolt from all thread 6mm by 1.0 and getting it back within tolerance. It’s working now and may have to put a clutch on later however tractor only has 800 hours so should have life left. Thanks again for the feedback. Air would work until the tractor got hot and once it cooled down it would work again

There are shims available from Kubota to adjust the clearance in those clutches. You remove the bolt and the front part of the clutch and you will find a washer (shim). these are the part numbers for the optional shims.
T0070-87340 SHIM 0.10mm
T0070-87350 SHIM 0.15mm
T0070-87360 SHIM 0.40mm
T0070-87370 SHIM 0.60mm
T0070-87380 SHIM 1.00mm

 

[fried1765]

Thanks for the reply but looking for someone who had experienced an issue with the clutch not engaging which is part of the diagnosis. Had the tractor quit cooling and not started back cooling again I would be looking toward the compressor, low freon or something mechanical. Currently I am looking at the electrical by seeing if the relay is sending power to the clutch and the easiest ($16) way is to unplug a relay and replace it with a new relay knowing that if it starts working it may not be the fix but rather the tractor deciding to once again engage the clutch and cool. Air flow is not the issue as the clutch is not engaging. I do need assistance if anyone has the electrical knowledge of what wire/voltage causes the clutch to engage as reverting back to the old pressure switches from the 70's I used a paper clip to cause the compressor clutch to engage to allow me to add freon 12 back in the day it was .99 cents a can and no one knew that we even had an ozone layer. I made a visit to talk to the local service manager only to find out that this will be his first rodeo on electrical on the L series as other than adding freon a time or two the L series air conditioning seems to be solid. Anyone with the electrical schematic of the air circuit would be a great help as I haven't been able to locate it online other than a small drawing that has the relay I plan to change in roof accessign from the top.

Thanks.
Your comment just reminded me that I still have a 30 lb. bottle of R12 that is almost full.
I need to find a market to sell that.

 

[number two]

Big Bucks I thinks!

 

[DustyRusty]

Thanks.
Your comment just reminded me that I still have a 30 lb. bottle of R12 that is almost full.
I need to find a market to sell that.

The market for R12 is actually declining because more people are switching over to R134, even though is isn't as good as R12, but the price is so much less. I can remember when I could buy a can of R124 for 99 cents. Today it is about $10 a can. I still use R12 on my own cars, and I have an adequate supply for my needs. Today most refrigeration people won't go near an R12 system because they don't understand it. I grew u on R12 and fully understand how it works and how to keep it in the system.

 

[fried1765]

The market for R12 is actually declining because more people are switching over to R134, even though is isn't as good as R12, but the price is so much less. I can remember when I could buy a can of R124 for 99 cents. Today it is about $10 a can. I still use R12 on my own cars, and I have an adequate supply for my needs. Today most refrigeration people won't go near an R12 system because they don't understand it. I grew u on R12 and fully understand how it works and how to keep it in the system.

Any idea how many pounds/ounces in a $10 "can"?
I think my 30# tank probably has about 27 lbs. remaining.

 

[DustyRusty]

Some are 12 and 14. Occasionally you find a 16 oz can, but those were rare. I will give you $250 for it if you deliver. Put it inside of a Home Depot heavy duty box so it isn't seen by passers by.