Trying to fill A/C system; blows hot air and high side has low pressure

[jangell]

The water pump replacement took longer than expected (partly because I had to remove the Y pipe, forgot to replace the O-rings, and had to remove it again when the valley filled with coolant...), so I didn't get to much of the A/C system yet. It's also going to be in the high 90s this weekend and humid, so I might wait another week before doing the rest of the list.

Mounting: I'm sure the compressor is mounted correctly. The mounts cannot be removed from the compressor body, it only mounts one way, and the drain plug is mounted on the passenger side above the mid level (so not all the way on top, but as on top as it gets for this, it seems).

Oil: I have not checked the oil level yet. I know it came filled from the factor, but now I've filled the system (probably mostly with air) and emptied it, so did I take some significant amount of oil with it? It ran for 10-20 minutes at most, but I don't know if that's enough to circulate a significant amount of oil out of the compressor. Do I need to drain it and refill it, or should I be fine as-is? I can pull it if need be; it's just a bit of a pain (have to take off the belt, remove the air intake on my car, remove the lines, unbolt the compressor), so if I can be lazy I'd prefer that. But I'd also like a working A/C system.

Routing/Connections: I took the passenger side hose off of the compressor to try to shine a light in there to read the "S" or "D" on inside when I noticed the giant "S" and "D" printed on the back of the compressor casing itself that I somehow didn't see before. I traced the "S" side hose and confirmed that it connects to condenser, and is in fact the low side. I tried to turn the compressor by hand with the clutch engaged to see if I could feel suction, but I couldn't turn it fast enough for that. I'm thinking of taking the "S" like off, turning the car on, and using a PowerProbe to briefly power the compressor and see if I feel suction, just to confirm that it's turning the right way. However, this is the cross-reference part for a 1989 Eagle Premier, so it seems likely that's already correct.

I checked all the other hose routing and they seem to be fine.

Accumulator: The system is currently filled with air at atmospheric pressure. I didn't get around to replacing the accumulator and orifice tube yet (but I do have them). I assume I should do this before trying to fill it again. Hopefully since they were only put on a year ago they won't be too hard to take off. I was going to try it this morning, but it's already pretty humid and I have to do day-job work, so it'll have to wait.

I also found out that the knob on my manifold set that opens/closes the yellow line seems to be stuck on "open" and never seems to seal closed. Simply closing the low/high knobs should let me work around that problem, and my can side tap has a Schrader valve that should keep the yellow line purged while I switch cans.

I'll report back after testing, but I'd like some opinions on if I need to bother checking the oil. I'm just assuming that the accumulator/orifice need to be replaced at this point unless someone tells me otherwise. I mean, I could just fill it now and see if it works, but I'd kind feel bad about having to vent R134a if it doesn't.

Thanks!

-- Joe

[Bitsyncmaster]

You don't loose much oil doing the evacuation and refill. The question is what kind of oil came in the compressor. I would drain the compressor and add the oil type you want. I would also flush the system but not sure how much oil you now have in the system. Defently change the accumulator right before your ready to fill the system. The accumulator holds a few oz. of oil and being open in these humid days would fill the desiccant with water.

[jangell]

The specs page for the Four Seasons 58555 says that it comes pre-filled with 3 oz of PAG, so I'll leave it at that:

Our products are engineered and tested to provide years of trouble free operation. Backed by over 50 years of mobile a/c experience, fix it once and fix it right with Four Seasons.
New Compressors meet or exceed OE specifications
New Compressors are validated for the equivalent of 100,000 miles
New Compressors come pre-charged with 3 ounces of PAG oil for R134a or R1234yf applications
New Compressors come with direct fit connectors for ease of installation and to help eliminate splicing
New Compressors come with the R12/R134A/1234yf required o-rings /sealing washers to install the compressor
New Compressors are built in a ISO9001:2015 Certified facility. These facilities go through several audits to ensure quality standards in the manufacturing process.

I'll definitely replace the accumulator/orifice before vacuuming and filling it then. We'll see just how hot it is this weekend, but at worst I hope to do it next weekend.

Thanks!

-- Joe

[DMC-81]

Oil: Was the entire system flushed and or brand new when you started? If so, and you're confident that the new compressor was filled with the correct oil amount, then I think you will be good. If not, perhaps it would be prudent to flush the system and drain the compressor and start again.

My system had a blockage of too much oil in the evaporator, a condition called "oil logged". (Not suggesting yours is the same, but just illustrating that too much oil in the wrong place can be a problem.

Because your pressures are out of whack, I would check each component for a blockage before charging it again.you can do this by blowing compressed air through each component.

Accumulator: Yes, you should change the accumulator as the last step before vacuuming it down and recharging. As you may know, it has desiccant inside and can't be flushed or left to atmospheric pressure.

[jangell]

Oil: The system has never (successfully) been filled before, and everything in it is new and set up for R134a, so there's no old oil to worry about.

Accumulator: I was hoping that I'd held it at vacuum successfully for long enough that, but I was pretty sure that this was no longer the case and need to stop being lazy and just replace it.

Thanks!

-- Joe

[Bitsyncmaster]

Note a lot of people think holding a vacuum will pull moisture out of desiccant. That is not the case. It takes heat (about 250 deg. F) to remove the moisture from the desiccant. Now if you had an accumulator without any oil in it from being used, you could bake it for an hour or two but that would be very messy if oil was in it.

Some of my electronic components need to be sealed in jars with desiccant until they are soldered onto the circuit board. The reason is the moisture can crack the seal of the plastic case during soldering. So I tried to rejuvenate the desiccant by just holding it at a vacuum for one week and it did nothing. Put it in the oven for one hour at 250 deg and it's like new again.

[jangell]

I wouldn't have thought of heating it to refresh it -- I just figured it was junk and that was that. Although once you get the accumulator out it seems to make more sense to simply replace it, since they're not expensive and you've done all the hard work. I guess if you don't have a replacement handy it makes sense to try to rejuvenate it, though. I admit I'm tempted to keep my old one as a backup and use that trick if I need to swap it out again in a pinch (or if I screw up filling it again ).

Having to keep certain electronics components dry before solder is quite interesting -- that's not something I'd come across before.

-- Joe

[Ron]

Mounting: I'm sure the compressor is mounted correctly. The mounts cannot be removed from the compressor body, it only mounts one way, and the drain plug is mounted on the passenger side above the mid level (so not all the way on top, but as on top as it gets for this, it seems).

The mounting is correct if it sits at the same angle as it does on a 1989 Eagle Premier. It will work but you have to look in the manual and follow the steps to check total amount of oil in the system.

Oil: I have not checked the oil level yet. I know it came filled from the factor, but now I've filled the system (probably mostly with air) and emptied it, so did I take some significant amount of oil with it? It ran for 10-20 minutes at most, but I don't know if that's enough to circulate a significant amount of oil out of the compressor. Do I need to drain it and refill it, or should I be fine as-is? I can pull it if need be; it's just a bit of a pain (have to take off the belt, remove the air intake on my car, remove the lines, unbolt the compressor), so if I can be lazy I'd prefer that. But I'd also like a working A/C system.

10 minutes at idle is the time required to distribute the oil before measuring it according to the WS Manual.
If "everything in the system is new", note that Sanden shows 6 ounces is typical for total system oil charge for a 508 compressor (stock for D). A D will require more because of the long lines. I would guess 7-8 total. If you didn't change the evaporator and condensor, and you didn't flush the system, then the 3 oz that came with the compressor is probably enough. But, like Dana said, there may be too much, depending on what went wrong to begin with, etc.

Routing/Connections: I took the passenger side hose off of the compressor to try to shine a light in there to read the "S" or "D" on inside when I noticed the giant "S" and "D" printed on the back of the compressor casing itself that I somehow didn't see before. I traced the "S" side hose and confirmed that it connects to condenser, and is in fact the low side.

This confirms that you have the wrong routing.

I tried to turn the compressor by hand with the clutch engaged to see if I could feel suction, but I couldn't turn it fast enough for that. I'm thinking of taking the "S" like off, turning the car on, and using a PowerProbe to briefly power the compressor and see if I feel suction, just to confirm that it's turning the right way.

Virtually all compressors are turned clockwise. It is turning the correct way. "Powering the compressor" doesn't help anything here. Turning the clutch only will make it pump.

I checked all the other hose routing and they seem to be fine.

Can't be fine if the suction is going to the condenser.
And, as mentioned before, it having hot-cold-hot-cold spots indicates you have something wrong concernig routing and/or blockages (oil, hose,?).

Accumulator: ...
I'm just assuming that the accumulator/orifice need to be replaced at this point unless someone tells me otherwise. I mean, I could just fill it now and see if it works, but I'd kind feel bad about having to vent R134a if it doesn't.

Oil: The system has never (successfully) been filled before, and everything in it is new and set up for R134a, so there's no old oil to worry about.
Accumulator: I was hoping that I'd held it at vacuum successfully for long enough that, but I was pretty sure that this was no longer the case and need to stop being lazy and just replace it.

I would not install the new accumulator until I had the system cooling...and oil checked depending on whether it is ALL new or not (see "OIL:" above).

The accumulator is shipped with an inert gas and its caps should not be removed until you are 100% ready to connect it up. Minutes and seconds matter. Also, the desiccant in the accumulator can not be dried out by placing it under a vacuum. It binds with moisture and it takes relatively high heat to release it. Heating it to the required temp will usually destroy the desiccant's container.

Edit: Sorry for duplicate info ( Dave beat me to the last part;-)

[jangell]

The mounting is correct if it sits at the same angle as it does on a 1989 Eagle Premier. It will work but you have to look in the manual and follow the steps to check total amount of oil in the system.

AFAIK it does, but I never had a complete Premier/Monaco to look at, so I don't know for sure. I just know that the compressor is correct for a Premier according to the Four Seasons lookup site.

10 minutes at idle is the time required to distribute the oil before measuring it according to the WS Manual.
If "everything in the system is new", note that Sanden shows 6 ounces is typical for total system oil charge for a 508 compressor (stock for D). A D will require more because of the long lines. I would guess 7-8 total. If you didn't change the evaporator and condensor, and you didn't flush the system, then the 3 oz that came with the compressor is probably enough. But, like Dana said, there may be too much, depending on what went wrong to begin with, etc.

I was wondering about the 3 oz thing. A quick video I found today showed refilling a Sanded-style condenser with 6 oz of PAG, like you said. I did change the evaporator and condenser (and everything else), so based on what you've said that 3 oz is probably not enough. I have a can of full PAG that I haven't used yet.

This confirms that you have the wrong routing.

I am constantly getting which side is which turned around in my head. I need to print that diagram and stick it to the wall or something.

Here's a bad picture of the back of the compressor, showing the "S" and "D" connections. The disconnected line is the one that I originally thought was the high side line, then figured was the low side based on the readings from the gauges. Turns out it's the high side line, but not the high side of the compressor.

IMG_1840.jpg

I just went out and put a loose zip tie on one of the lines and slid it down from the compressor to the frame to make sure I absolutely know which hose is which. The line from the S side of the compressor is definitely going down the driver's side of the frame towards the condenser.

Now the question is how to swap them. I'm hoping I can just switch the hoses at the compressor (assuming the connections are the same size), but I think one of them has a threaded connector while the other doesn't (it's held on by a bracket, like in the original setup), and that concerns me a bit. I'm not going to be able to go back out and take things off today (way too hot and humid), but it'll be cooler tomorrow so I'll check it then. It would be so very convenient if I could just switch them.

Looking at the parts manual diagram https://store.delorean.com/c-303-7-2...ve-system.aspx I have the routing physically correct, except for the fact that these are not the S and D ports on my condenser, which makes it incorrect.

This is the thread where I asked for recommendations for the compressor, BTW: http://dmctalk.org/showthread.php?16...ecommendations. I'll note that Farrar's picture of an Eagle compressor installed shows the low side on the passenger side, just like on my compressor, but I have the hoses connected wrong. And the oil drain plug is in the same place, so it seems I have it mounted correctly.

Virtually all compressors are turned clockwise. It is turning the correct way. "Powering the compressor" doesn't help anything here. Turning the clutch only will make it pump.

I wasn't sure if I could feel the suction by disconnecting the line turning it and seeing if it sucked or blew while the clutch was engaged. That was the theory, anyway. Assuming the ports are labeled correctly on the back of the case, I don't need to do this test.

Can't be fine if the suction is going to the condenser.
And, as mentioned before, it having hot-cold-hot-cold spots indicates you have something wrong concernig routing and/or blockages (oil, hose,?).

I would not install the new accumulator until I had the system cooling...and oil checked depending on whether it is ALL new or not (see "OIL:" above).

That sounds like a plan to me. This weekend (weather permitting) I'll check the oil in the compressor, add to it as needed, fix the hose routing, and then fill the system again and see if I actually get cold air. Only after it works will I replace the accumulator.

The accumulator is shipped with an inert gas and its caps should not be removed until you are 100% ready to connect it up. Minutes and seconds matter. Also, the desiccant in the accumulator can not be dried out by placing it under a vacuum. It binds with moisture and it takes relatively high heat to release it. Heating it to the required temp will destroy the desiccant's container.

Edit:Sorry for duplicate info ( Dave beat me to the last part;-)

Got it -- Dave's comment was more about his electronics desiccant, not about the accumulator. I'll consider the old one junk then.

I have not and will not remove the caps on the accumulator until it's time to install and fill it. I knew this before, but it's good to have it reinforced. Thanks!

-- Joe

[Bitsyncmaster]

Just remember the S stands for suction and is routed to the low (gas) side which is on the passenger side of our car. The D is the discharge side (high side) and is routed to the condenser via the drivers side on out car.