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Radiator Coolant exiting Low Pressure Port / Water Pump Replacement (Double Jeopardy)

I took my 2004 Ford Ranger XLT (4.0 SOHC) into the local Midas shop to have my oil changed. They noticed that radiator fluid was beginning to seep out the water pump pulley seal and recommended that I replace the pump before there is a failure. I had the shop replace the water pump. I also requested that they check the A/C system to ensure it was in good shape. There was nothing wrong with it, I simply wanted to be proactive. This was 6/19/2014. I was told that I needed a recharge of the A/C system. I live in Seattle where you need A/C only 3 days out of the year. I let it slide. The pressure readings were 30psi/180psi/45degrees
This past Saturday, I purchased an A/C recharge kit because my A/C does not blow cold air, and hasn’t since about the time I had it checked.The low pressure port is at 100 PSI! Also, the clutch does not engage on the A/C pump. I tried charging the system with just a couple shots from the recharge can but no luck in getting the clutch to engage.So, I used a bicycle wheel spoke to let some pressure out of the low pressure port and I noticed green radiator fluid collecting on the spoke. Is this normal? My radiator fluid is straw yellow (color of a dehydrated person’s urine). I believe the radiator fluid was green before the pump replacement.

The A/C worked beautifully before the water pump replacement. Did the shop mess something up? I wrote a very ugly review in Yelp and they wish to verify my issue. I reacted emotionally without any technical facts and wish to verify the technical probabilities before responding to the shop. Given the relationship between the engine coolant system and A/C system, something is not right and I believe they sabotaged the A/C system for repeat business. Thoughts?!

There is oil in the ac system. The radiator is a totally different system. There is noway to get radiator fluid in the ac or ac oil in the radiator. You need to fix your Yelp comment.

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How does oil get into the A/C system…?

Special oil is always added to an A/C system to lubricate the compressor.

Your pressure readings are within acceptable ranges. Maybe a slight touch low on the low pressure side, but still within range.

The color yellow/greenish you see is probably from the refrigerants. Some dealers will add a UV dye, which makes it easier to check for leaks.

Are you sure the clutch is not trying to engage? Maybe you want to look again while someone else is turning the a/c on and off repeatedly. You should see the clutch wanting to engage. It’s located right in front of the a/c pulley. When the a/c is not engaged the clutch does not spin in tandem with the pulley, only when the a/c is turned on the clutch spins together with the pulley.

One other thing you might want to try is turn on the a/c and observe the clutch. If it does not spin give it a little push with a long screwdriver or something similar. If you have a worn clutch assembly, it could be possible that the coil is no longer strong enough to engage the clutch. If that is the case it is easy to replace. I just did this a week ago on my wife’s Acura.

If that does not work come back and let us know. There are also tons of youtube videos on this subject and how to troubleshoot.

knfenimore is talking about compressor oil inside the a/c compressor.

Gotcha…thank you so much. Makes sense. The perceived green radiator fluid was translucent. So, was likely the dye used to check the system. I will spend some more time with it. The vehicle is under the airbag recall and I was fearing that the motor was a total recall. Hehe…

You shouldn’t post your real name :warning:

I suggest you edit your post and remove it :wink:

The most common reaction to an unexpected failure like this is to return to the shop and have them review their work, overlooking a connector isn’t unusual.

However with that Yelp review it might be best to seek assistance elsewhere.

You had the A/C on a 10 year old truck checked in 2014 and the readings listed indicate the system could possibly be a little low.

The pressure reading when you tried to recharge it is fairly normal for a non-operating system. The green substance you saw when you vented the A/C system is UV dye that many systems have to help identify leaks if and when they occur.

It’s possible the A/C system simply has a loose or unplugged connection somewhere, or the trouble could be completely unrelated. The car is now 12 years old and that A/C has been operating more often than not for those 12 years. The A/C in your truck is operating whenever you have the defrost or heat/defrost blend on, which in rainy Seattle is quite often.

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Thanks, done. I tend to put myself out there unnecessarily…

With the motor running and A/C turned on, I did try to get the inner part of the A/C compressor pulley to spin with a long tool. No luck. Also checked electrical connections.

The recharge can has a guage on it, and the first part of the instructions has you check the current pressure on the low side port. At 100 PSI it almost pegs the needle…it is deep in the red. The PSI numbers stated above are from June 2014. 30 PSI is in the green on the recharge can. I will review the technical manual, as I am unsure if all A/C systems run at the same pressure.

The previous comment about it being within acceptable range doesn’t make sense. That is if you thought that those numbers are current (30/180/45). They are not. The low side port reading was 30 but is now at 100. I do not have the correct valve adapter to read the high side port. I can tell you that the tubing around the high side port does start to get cold when performing the low side port test, even though the clutch does not engage and spin the A/C pump.

The pump could be toast as I tend to drive hard, and driving hard with the A/C running may not be beneficial to the longevity of the pump.

I’m not trying to be flippant but since it appears you don’t understand how automotive A/C works you’ll have to take my word that the readings from 2014 AND today could both be normal.

The pressures from 2014 could either be normal or slightly low, depending on ambient temperature and engine speed when the readings were taken.

100 psi for a non-operating system on a warm day tell me that the system is likely pretty close to a full charge. The lack of A/C operation at this point is likely caused by an electrical or mechanical problem somewhere.

Have you verified the ac compressor clutch is getting a signal to engage?

More than likely your low and high side pressures are the same . . . because when the compressor clutch does not engage, you will only have static pressures

If I were you, I’d make sure the compressor itself isn’t seized . . . that means, when the engine is OFF, see if you can turn the clutch by hand. If you can’t even turn it by hand, that does not bode well


I am here to learn and ask questions. I am not afraid of looking like an ass because no, I don’t know how an A/C system works. Does that help you get over yourself? Pump is probably toast. Thanks…

The needle in the red and reading 100PSI is not an accurate reading. It would be best if you look on youtube. There are lot of examples about how to read the gauge and properly top off a/c refrigerants from a can. You also find video clips on how to test the clutch. Seeing it done is easier to understand than reading our poor English.

You really do want to find out where the problem is, if there is one, either the clutch or the compressor. A clutch kit costs you $60 bucks to replace and does not take special tools. Replacing a compressor cost you upwards of $600 and if you do not have a manifold gauge and a vacuum pump you need professional help…

Driving hard is not going to hurt the pump unless your are taking your car to the Indy 500.

After all this witty banter, and viewing a few You Tube videos, my A/C system is most likely so low on refrigerant that the A/C pump (clutch) is not engaging. Also, the low side pressure check is reading really high because the A/C pump is not spinning. Once the clutch engages the reading will be an accurate number.

One more question. Do you leave the vehicle running with A/C Max on (with fan on full) when discharging a can of refrigerant in to an empty A/C system? This part was not crystal clear in any of the videos. I assume so but asking here for clarity.

P.S. Can’t wait for the Italian M3 the arrive on US soil. :wink:

100 PSI is sufficient pressure to turn on the compressor. Check the wiring and connector to the compressor, check the connectors at the pressure switches.

Yes, turn the a/c on full blast while you discharge the can into the engine. Get a can that has a gauge attached and follow instructions. The needle on the gauge will show you when you have sufficient refrigerants in the system and then stop. Do not overfill it.

By the way, as you start to discharge the can the compressor may not be on because the clutch is not engage. As the pressure increases inside he lines the clutch may suddenly engage. That is perfectly normal and expected.

Will do an electrical check as first step. Thanks kindly.

Someone up there noted that if the low side pressure is 100psi with the compressor not operating the system is likely fully charged. That fact seems to be overlooked in several posts here. With a static pressure of 100psi the pressure switch controlling the compressor clutch should be closed to command the clutch to engage. The pressure on a can of R-134 is likely below 100psi so it is useless to try to add any unless and until the compressor is operating and the low side pressure drops below ~30psi.

See, now we are getting somewhere. This is the stuff You Tube doesn’t cover and where learning begins. Cheers!