A/C clutch questions

[harpon]

I'm actually evaluating A/C problems on a Hyundai- but thought I post a question or two here-

In general- can an a/c clutch be serviced or replaced on a compressor without removing it from the car and/or draining the refrigerant?

It seems like the clutch kits are pricey and it may be better to just replace with a new or rebuilt compressor- any opinions?
There's a grounding screw on the top- I think- I intend to clean but not giving it all that much of any chance of solution

I bought the car last summer- the a/c worked though not super cold- this spring it does not blow cold- tried adding refrigerant with little effect-

I put in a can of PAG oil- only 1 oz oil and two ox of refrigerant and another can of R134- it seemed to kick the compressor in gear-

it was cooling great- but did not cool down a few days later- and hard to evaluate even in Florida due to cold days-my first impression was that it was a leak
after that I put more charge in- another can of PAG oil and a can of Stop leak-and got a nice cool again that did not last-

with a warmer day today I got out there with art of the last can remaining and the gauge attached and it seemed to be holding pressure at between the green and blue lines on the can- so it may not be a leak-

but a faulty clutch on the compressor or ????? The a/c has worked great- better than last summer for two short periods this year now after adding stuff, and there seems to be fairly good pressure in the low side. I might suspect a relay or electrical problem if it didn't cool sooo well after 134 and separate (small quantity) of PAG oil.

I'm going to use another gauge and test again tomorrow- had to stop for darkness tonight

If I order a compressor, do you think it would be good to replace the line hoses and o-ring for another &60 or so in parts at the same time?


Thanks in advance, and for the cause, right?

[FestYboy]

To answer the first question, yes it is possible to replace just the clutch assembly. It usually takes a specialty tool to press it off. A whole remanufactured compressor it usually cheaper. To diagnose the issue, disconnect the positive lead and do a continuity test of the coil. Then with pressure in the system, do the same to the high and low pressure switches. If any of those don't check good, replace the faulty part. There should be at least 50psi in the system for testing. If you find that those components check good, run the system and verify that the cooling fan runs with the clutch engaged. I recommend you roll over to harbor freight and invest in a a/c manifold set to monitor pressures.

[F3BZ]

if you are confident there is enough refrigerant in the system look at the clutch face with the engine and AC running. if it is cycling on/off every few seconds (clicking on/off), i would look next at the low pressure switch mounted somewhere on the suction line in the engine compartment coming from the evaporator. this should have 2 wires leading to the compressor. if you remove the wires and jumper them and the clutch stays pulled in then the problem probably isn't the compressor/clutch. i would want to put gages on the system to get actual pressure readings but if i'd start suspecting the low pressure switch. another remote possibility is ice blockage in the suction line due to air/water vapor contamination but this shouldn't occur unless the system had been open to atmosphere.
depending on the model hyundai, there could be other switches such as a temp switch near the evaporator that could be causing a problem also.

[harpon]

Put another can in- it, again , seemed to kick the clutch over with the refrigerant pressure, and the air blew very cool- I kept going out and starting it through the evening so the clutch would be less likely to freeze and ordered another can of PAG 46- then thinking it might just be a reluctant clutch in need of more lubricant- I'd already used two small cans with only 1 oz of oil and 2 of 134 refrigerant and both times the seemed to click the compressor over.

I also found the pressure switch behind the coolant reservoir, but I'm wondering if this releases pressure in the lines with threaded installation? I'm holding a new one in my hand right now, and I guess this also may be a/the problem-
-
Today I started it up- and same thing again now- no cooling .Yet this evening I went to try to see if I could get more of a remaining can into the line- the can was empty- but I tried to get a pressure reading with the gauge and it appears that the pressure is down again- if it was accurate- so again it appears a leak in the system. At the same time, my can adding gauge seems to have gone bad- I'm not sure it will open another can, and I've had terrible luck with these lately. So now I'm flying blind again.

If the pressure is down- I can put the new pressure switch on either way I guess- again does the installation drain the pressure or does the threaded connector work otherwise- it appears to be a female insert inside the male threads- like pressure pushes a rod into it? and then it changes current on the 4 pronged connector end?

I'm not sure what I'm going to do now- It appears there is in fact a leak and I guess the system simply won't work after the pressure drops. I've ordered new lines and wondering about the possibility of it leaking at the compressor or condenser. The compressor seems to work fine under the right conditions- and that looks like it may be contingent on pressure. Replacing the o rings and expansion valve might cure the problem but I'm worried about using- and then losing- more Freon. Seems like using new lines would shift any further leaking onto the compressor or condenser.

A few years back, I may have been able to replace at least some of the o rings or maybe even get new lines and an expansion valve on- but my health isn't that great right now.

With the labor involved replacing the lines, I'm leaning toward a new compressor too- about $150 new, and a $6 bottle of PAG46 oil. What is a ballpark figure on labor to replace the lines , o rings, expansion valve and compressor ? Should I spring another $15 for a new drive belt? 04 accent with 86K, clean otherwise-

[ryanprins13]

Clutch should be external and not related to how much oil you put in the system. Pressure switch as far as i know just shuts off the compresser clutch if the pressure gets too high or too low.You can check for voltage at the plug connected to the compresser. It activates the clutch.
Sounds like you have a leak so when you fill it it works, pressure drops enough over time so that the pressure seitch wont allow the clutch to engage. Or you have a bad pressure switch.
A/c systems are closed, they and you arent allowed to release whats inside to the atmosphere.

Sent from my SM-G920W8 using Tapatalk

[FestYboy]

First, if the description is accurate, then you have a leak, and a fast one.

Find the leak first! Throwing parts at an a/c system will get expensive. Get a local shop to insert some dye and pressurize the system. The dye is UV reflective. Replace the offending parts. Once the system is sealed, go back to the shop and have them vacuum test it. It should hold 28+" hg for at least 10 min. Then have them pull on the system for at least 30 more minutes to boil off any moisture. Moisture kills an a/c system. If the compressor wasn't changed, you don't add any more oil.

[harpon]

If In pull off the pressure switch, does that usually open the system?- I can probably change that, but I'm more leaning to a complete rebuild, or at least having the lines, o rings and expansion valve changed- so far that's about $75 worth of parts- I can't do much here- the car is parked out front, and I have no special tools. I've heard the dessicant dryer needs to be replaced in the accumulator on the side of the condenser but I can't really see where that would be added. A bag of that too is on the way.

If I get the lines replaced that would leave only the compressor or the condenser as possible sources of leaks. This is Florida and getting hotter all the time IMHO. If I get the lines put in and new refrigerant- and pay for that labor I think I may just shoot the works and get a new compressor for $140 or so- to make sure there are no foreseeable problems. A new condenser would run another $55 or so and seems like it would put yet more labor on the project. I may take my chances on using the old condenser even though the dessicant has to be added- if that requires removal- I' m wondering- the old parts don't look bad-unless it got hit with a rock or something.

I just don't want to pay for more labor later- The parts total can be just over $200 without the condenser. I think $140 for a new compressor though is a good hedge against further problems. There isn't any core charge ordering one on line apparently. I've found that some of the parts on this Accent have been pretty reasonable- I paid only $8 delivered for the pressure switch, and got some door hardware for $5 and under last summer. I think they sold a lot more of these units than Aspire or Festiva, and it's just 13, some kind of proverbial musical knee-high- as I was 50 years ago in the summer of love when they were playing "Nashville Cats" on the radio..

https://www.youtube.com/watch?v=P4p7prURvIk

[F3BZ]

the pressure switch "should" be threaded onto a bung that has a shreader valve like a tire stem so it should close to hold pressure. i agree it sounds like a major leak. a way to possibly pinpoint a leak visually is to look for any buildup or streak of greasy dirty oil around any pipe connections. escaping refrigerant will carry a little oil out with it which over time will attract road grime.
if you think the system is almost empty, might as well change out the switch. as long as you do the changeout quickly, outside air shouldn't enter the system. even a system that shows 0 psi usually has enough refrigerant entrained in the oil that is boiling off enough to maintain a fart of pressure above atmosphere. of course eventually it will equalize if let go long enough. if you are really lucky, you'll find a leak at a joint that can be eliminated just by tightening the joint. i'm never that lucky.

[FestYboy]

The pressure switches are not valved, remove one and you open the system.

The test ports ARE valved and the valves can be replaced without opening the system, but it requires a special tool that isn't cheap.

Harpon, you're forgetting about the evaporator: the crappiest part of the system to get to. And the hardest to diagnose for a leak, AND the second most prone part for leaking due to its construction. The first being the condenser due to its location.

I can't stress enough: diagnose first, then replace.

I do a/c and major auto repair for a living. If I didn't follow the above mantra, I wouldn't have the client list that I do.

[harpon]

Well I just got to it again-

About the evaporator- I see the part liste on ebay, and even pictured in a crappy schematic- but I still can't locate it- looks like it has two hose connections, but doesn't seem to be on the car connected to either the suction or discharge hoses- is it in the cabin or firewall otherwise? maybe behind rthe exopansion valve on the firewall?

Anyway- I put a couple of questionable gauges on the low port- and got no reading at all- tried to push the top of the valve top with a phillips head- no response-

so at that point I got the valve remover tool- $4 stateside on ebay and as low as $.99 if you wait from Hong Kong- and I extracted first the low side valve and then the high side- absolutely NO PRESSURE in the lines- I put them right back in for now.

http://www.ebay.com/itm/232182482934?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

I maybe failed to mention about the second time I put some refrigerant and oil in the system, and a can of stop leak- there was a slight bubbling at the low side valve I wasn't sure was stop leak residue or a leak- anyway I also ordered a set of new valve cores when I ordered the core remover tool- Today I see a slight green residue around the high side core, and wondering if that's PAG46 or possibly the Stop Leak.

http://www.ebay.com/itm/252770425924?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

So I have those if I need them on the new lines- looked around some more and decided this strategy- I will replace the lines and O-rings, with new valve cores- I may even be able to struggle through it myself, but not adverse to getting help either- Then also the new expansion valve coming,

http://www.ebay.com/itm/191925722959?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

and the new pressure switch I have. Then I think I'll try to charge the system again and see if that holds- all I can lose is some refrigerant- and the compressor seemed to work with pressure otherwise.

http://www.ebay.com/itm/222207491725?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

If it still leaks or doesn't work otherwise I'll go from there- I may order a new compressor while the price is down- to sit beside the rebuilt Aspire alternator and the Festy calipers and pads still uninstalled- Or maybe just wait until that fails, knowing I put new lines in in 2017.

The 91 festy is still not starting as of winter despite a new fuel pump and relay- it's still not powering the fuel pump, so the battery will go back in that soon if I don't sell it soon.

[FestYboy]

The evaporator is under the dash, the low and suction lines go into the firewall.

I would inspect the condenser face for damage. Also look for residue at the evaporator drain tube. Since you mentioned inserting sealant, get a UV light since the sealant Hase dye in it already.

[harpon]

So I just got the expansion valve- it appears the that the evaporator attaches to the firewall side- with the same kind of O-rings. It seems then that that may remove most of the possibility of that leaking I'm hoping- it hasn't gotten bashed around- I haven't driven the car since last Fall. I probably wouldn't have even bought this Accent if I hadn't thought the Aspire tranny was shot- it turned out there that the shifter was gradually falling through the floor- and fixed with window weld- I've driven it all winter now.
I don't guess there is much chance it simply explodes on it's own, but stranger things happen I guess.

Is there any special application or sealant with the O-rings and new lines, or do thy just sit in the recesses and seal by themselves?

[FestYboy]

A dab of PAG oil during install is all you need.

As for the evaporator leaking, I should have specified that it may be leaking from the core due to acid erosion (moisture).

Again, I would insist you find the leak first, but if you're more comfortable throwing parts at it and crossing your fingers... Not my $, not my car. Hopefully, for your sake, what you have into it fixes the problem.

[F3BZ]

in rebuttal, i too have a "diploma" in HVACR. even though most of my experience has been residential/commercial i spent many summers in used car lots patching iffy systems so the car could be "COLD WHEN IT'S SOLD". i will confess to having little experience with most anything beyond 1993 nor care to.
most systems back then, especially lower priced cars had very simple control systems, usually a low pressure and temp switch to cycle the comp. high pressure was taken care of by a blow off valve on the comp.
low pressure switches don't often go bad but the few i did replace did have a shreader valve in the bung they screwed onto. maybe that's changed these days. that is why i put the word "should" in quotation marks. same as i put "diploma" in quotes. i'm not pretentious enough to equate my 20 month HVAC education with a college diploma and wasn't implying that the low pressure switch will have a valve. additionally, i wouldn't have suggested removal had i not believed that judging by the posts up to that point the system was pretty much empty.
i try not to help on the site with AC problems but sometimes can't help it. as seen in this situation, the problem is possibly being compounded by guesses and actions by the user potentially making the problem worse or at least unnecessarily costly and more complicated to get back to right. i very much advocate doing it yourself. most mechanical fixes can be learned by doing. unfortunately i don't think AC qualifies under that category. the AC system has mechanical, electrical, and gas states that change throughout, going through various pressure changes at different points and requiring special equipment and knowledge to diagnose i a logical progression of trouble shooting steps. how this all works together requires a good understanding of refrigerant theory mixed with a little mechanical and electrical understanding. it's something you're only going to learn by reading and studying.

[FestYboy]

Didn't mean to take a crack at you (F3BZ), and I apologise if it came off that way. And the line about experience was mentioned for Harpon's benefit, not a "I know better than you" jab.

I should make a concerted effort to be more direct about what and whom I'm speaking to.

Again, no disrespect intended whatsoever.