AC 8030 Air Cond Press Light On
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Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=149547
Printed Date: 10 Jul 2025 at 6:28am
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Topic: AC 8030 Air Cond Press Light On
Posted By: sjefferys
Subject: AC 8030 Air Cond Press Light On
Date Posted: 16 Apr 2018 at 8:13pm
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I inherited by grandma/pa's nice AC 8030 with 4433 hours. It runs great but recently the Yellow "Air Cond Press" sensor light comes on when I turn on the Fan for A/C. Don't know if this means there is a leak somewhere, or simply needs recharged. My knowledge of A/C systems is very little, however, I did see the compressor on the left side of the engine housing with a R-12 connection. Has anyone else experience this sensor light and have knowledge of how to fix? I have seen on some other posts there are more A/C components in the roof. I haven't explored anything up there yet. Not sure if it is hurting the tractor by running it with the light or what I need to do. In Texas and definitely need the A/C! Would greatly appreciate any feedback. Thank you.
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Replies:
Posted By: steve(ill)
Date Posted: 16 Apr 2018 at 8:24pm
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I don't know, but I would assume the light means the charge pressure is LOW and the compressor will not kick in.. You could turn the fan on, then get out and look at the belt on the compressor to see if the clutch is turning.... Its a good possibility that you just need some additional Freon in the system. If you get a can or two of R12, get one with a hose and pressure gauge with the quick coupler. You can couple the hose and start tractor.. Without the compressor ON, the HIGH and LOW side pressure will both be around 90- 100 psi. ( Your only reading the LO side).. When you start the compressor it sucks the LO side down to about 30- 35 psi and the HIGH side goes up to 180- 220 psi... If your pressure is less than about 20 psi, you don't have enough to start the compressor ( and maybe the light comes on??)... If you have ZERO pressure, then you need to look for a leak, and pull a VACUUM prior to adding any Freon. ------------- Like them all, but love the "B"s. |
Posted By: steve(ill)
Date Posted: 16 Apr 2018 at 8:26pm
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The low side fitting that you put the Freon can coupler onto is somewhere between the pump inlet fitting and the dryer ( the black can on the suction line). ------------- Like them all, but love the "B"s. |
Posted By: Dakota Dave
Date Posted: 16 Apr 2018 at 8:29pm
| If the AC pressure light is on the compresor should not be running. If the compresor is running one of the pressure switches is bypassed and it will ruin it. If it's not running. The pulley turning but the clutch not engaging it's fine check the pressure it's probably low or empty. it's empty most likely vacuum pump the system down. If it's got a large leak you'll know it won't hold a vacum. Now would be a good time to convert to r134a find a good AC shop. Since you probably don't have the equipment if you did you wouldn't be asking |
Posted By: steve(ill)
Date Posted: 16 Apr 2018 at 8:33pm
the DRYER I mention is also called an ACCUMULATOR... There will be TWO fans on the system.. The RED or HOT side will blow outside.. The BLUE or COLD side will blow into the cab... You can have both units on the roof, or one could be under the side window, im not sure on your unit. ------------- Like them all, but love the "B"s. |
Posted By: DSeries4
Date Posted: 16 Apr 2018 at 9:10pm
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The condensor is in front of the radiator. I would give it a good cleaning first to see if that makes a difference. However, you definitely need someone who knows AC units to properly diagnose the problem. As it is a pressure problem, some AC gauges will need to be connected and read. Don't make any assumptions yet. ------------- '49 G, '54 WD45, '55 CA, '56 WD45D, '57 WD45, '58 D14, '59 D14, '60 D14, '61 D15D, '66 D15II, '66 D21II, '67 D17IV, '67 D17IVD, '67 190XTD, '73 620, '76 185, '77 175, '84 8030, '85 6080 |
Posted By: wekracer
Date Posted: 16 Apr 2018 at 9:56pm
| That light comes on before the pressure gets too high or too low. That being said it also comes on if it’s too low or too high and kicks the compressor off. I have an 8010,8050 and 8070. The light is on in the 8050 the whole time the compressor is running. Pressures are 25 and 240 on an 85 degree day. If it’s cooling good and the pressure is good I wouldn’t worry about the light. As long as no one has messed with the wiring the low and high pressure switches will protect you from any damage. |
Posted By: SteveM C/IL
Date Posted: 16 Apr 2018 at 10:47pm
| When light comes on in my 8070,the compressor won't run.Needs gas. With my style compressor/pulley/clutch,you can't see if compressor is turning.Only the pulley. |
Posted By: Mikez
Date Posted: 16 Apr 2018 at 11:10pm
| Welcome to the forum. We like pictures if you want to share with us. Good luck |