A/C expert DIY advice

[bgd73]

Here is the short history of my diy a/c fix:

Found a/c condensor at junk yard today - less than half the cost of new with a guarantee.

A/c condensor worked -- did lose first attempt at filling system due to a rubber grommet I forgot. Replaced rubber grommet and added refrigerant again (134a) and guage said level is good.

It has been about 7 hours since fill up and pump kicks on for a few seconds and then it won't come on again. Guage shows system is full on the refrigerant bottle. I also added conditioner/sealer kit for 134a system and let it run for the 15 minutes it required. there is no audible/visible leak, and for the few seconds the pump comes on, the idle kicks up a bit like it is supposed to, and the air gets cold fast. Do I need to take it to a shop or what else can I do at home? Any help appreciated. BTW-- it is the very last part required to have my 93 loyale complete and error free (finally).

[DrKrazy]

Well I can only give you my insight from re-doing the A/C on my RX last summer with a new compressor, etc...except I kept my system on R12 since my Brother still has a ton of it. Anyhoo I had the same problem on my RX and it turned out to be just a tad overfilled. We pulled some R12 out of the system and it started working perfectly, Brother said something about the high pressure sensor turning it off. So maybe start with that sensor or level of refrigerant....

[daeron]

do you have the proper dessicant? because if your car was equpped with R12 in the first place, that needs to be swapped as well. Im no AC expert but ive learned a great deal in the last year or two, and all on my soob..

 

My older brother owned the car before me, and he earned his ASE A/C certificate while he was repairing the AC on this car, and it apparently USED to blow ice cold. he cared for the car, but drove it to hell and back, and didnt REALLY care for it as a mecahnic should.. more as a mechanic knew he could get away with. Nothings really bad about the car except for neglected rust.. but it has been driven, not babied by a mechanic.. nuff said. Anyhow, i got the car needing timing belts. did that, no clue what i was getting into beyond having done t-belts on a sohc geo/isuzu motor a few times (long story) and a nightmare with my buddy's 97 honda accord DOHC.. it was a 2.2 liter motor i think, and any mecahnics out there or anyone whos done a t-belt on the motor i did knows it... it was a PITA, but i got it done in the end (extra cash between jobs once. bad times.) so i did the belts on the soob np problem, but lost the bolts that hold the little pulse sensor thingy in front of the AC compressor. (note: if the term "pulse sensor thingy in front of the compressor" makes NO sense to you whatsoever, you are missing a little piece.) i found replacements, but poor ones, it held, but the ac never really worked good. probly needed charging then anyhow. six months later its summer and i try charging it... discover he never changed the valves to r-134 style, did that, and finally had him come over with his manifold, and we charged it right, but it barely worked... nada plus a sliver, in the heat of the south florida summer day.... at night, it blew cool. fast forward a year, that thingy has shaken loose and the wire got severed, so i replaced, got proper bolts, turned on AC, Lo and Behold, it blew cold!! cold enough, in the daytime!! i havent topped off the refrigerant yet (there was an issue that prevented from filling it 100% last year) but i just cleaned the condensor, and secured the aftermarket fan to the radiator at more than one point ( ) and its blowing even colder.

 

i dont know why i told you my tale, but you get the point.. that pulse sensor thing is important. its part of a mechanism that tells the car that the compressor is in fact, running. without it, the car thinks, hey.. its not doin nothin... that was how (i think it was GeneralDisorder) explained it to me anyhow. Its also exactly what i thought, i just never thought to check the alignment and tightness of the thing, i guess. minimal effort, it bites you sometimes.

[bgd73]

Well I can only give you my insight from re-doing the A/C on my RX last summer with a new compressor, etc...except I kept my system on R12 since my Brother still has a ton of it. Anyhoo I had the same problem on my RX and it turned out to be just a tad overfilled. We pulled some R12 out of the system and it started working perfectly, Brother said something about the high pressure sensor turning it off. So maybe start with that sensor or level of refrigerant....

 

That is a very good start. I am used to car a/c taking a few moments to get cool, I am getting blasted with very cool. The pump did kick off while I was putting more in, so the guage would read on the higher side of full. Will try to let some out and post again...

[Roundeye]

You really need a dual gage manifold so you can see what the high and low side pressures are. This will tell you alot. Aside from that, if it's a Hitachi compressor, check the air gap at the pulser. If it's too far away it won't stay on. You could also have a slipping clutch and/or belt(s).

 

If you know someone with a dual gage, post the numbers here along with outside air temp and myself or someone else can pinpoint the cause.

[bgd73]

thanks for replies. It was indeed an overfill. Rapid expansion after filling changed guage reading by triple over fill.. if system could handle that, I'm sure I'm all set. Also cleaned the aforementioned sensor and aligned closer.Now one more Q-- is the pump supposed to stay on all the time? that is what it is doing now. I thought it shut off once and awhile, and kicked in on its own again.Oh, well, its workin

Thanks alot! I can't wait for the hot muggy days ahead.

[GeneralDisorder]

Easy check - check that the belt sensor is hooked up and properly adjusted. If the system detects no belt movement it will shut the AC down within a few seconds.

 

GD

[GeneralDisorder]

It does shut off periodically - but only if you let it get cold enough - turn the fan down and it should cycle on and off.

 

GD

[skishop69]

I'm not sure about your sytem in particular, but almost every AC system has a low and high pressure switch. The low pressure switch tells it to shut down if the charge is low. If the switch is bad, no pumpy. The switch will be located on the larger diameter AC line near the accumulator (little coffee can looking thing). Unplug it and jump it with a paper clip. If the compressor stays on, replace switch. The high pressure switch shuts it down if the pressure is too high. This should be located on or very near the compressor on the smaller of the AC lines. Unpulg the switch and see what happens. If it stays on, replace switch. You may run into two switches in the vicinity of the compressor in which case one is high pressure and one is a cycling switch. This will actually cycle the compressor based on pressure alone. You can jump that with a paper clip as well and the compressor should stay running. Same follows, if it does, replace said switch. These are just quick tests you can perform without the manifold guages. As for the charging guage you used... throw it in the trash. It's barely useful for charging and certainly NOT useful for any kind of diagnosis. As Roundeye stated, you really should have a guage set to charge and diag.

[skishop69]

Geez, you just get the response typed and the problems already solved. I retract my former response. I'm going to the corner to pout

[GeneralDisorder]

No doubt - me too

 

GD

[bgd73]

I'm not sure about your sytem in particular, but almost every AC system has a low and high pressure switch. The low pressure switch tells it to shut down if the charge is low. If the switch is bad, no pumpy. The switch will be located on the larger diameter AC line near the accumulator (little coffee can looking thing). Unplug it and jump it with a paper clip. If the compressor stays on, replace switch. The high pressure switch shuts it down if the pressure is too high. This should be located on or very near the compressor on the smaller of the AC lines. Unpulg the switch and see what happens. If it stays on, replace switch. You may run into two switches in the vicinity of the compressor in which case one is high pressure and one is a cycling switch. This will actually cycle the compressor based on pressure alone. You can jump that with a paper clip as well and the compressor should stay running. Same follows, if it does, replace said switch. These are just quick tests you can perform without the manifold guages. As for the charging guage you used... throw it in the trash. It's barely useful for charging and certainly NOT useful for any kind of diagnosis. As Roundeye stated, you really should have a guage set to charge and diag.

 

Hey, that is priceless info. I am in fact copying it to a text file... My a/c is doing something odd, and what you have mentioned is last resort. It acts too high pressure , shuts down after a long "first" run. doesn't come back on until I do so, then it only stays on a few seconds again. this is after realizing pressure was way too high-- once the 134 gets agitated it really wants to stay there. When it is all calmed in the morning if it even calms down I bet pump stays on for quite awhile again. I just now ran it until the windows fogged (dewpoint is in high 60's -- I am stinkin :-\ ) and I caught a chill, before it never shut off. Then it shut off and doesn't want to stay on now. I will first take it to an a/c expert just for pressure checks then I am stuck with the old subes parts and switches to diagnose what is next. Thanks alot, info is very helpful I may be surprised to find over 30oz (should be 22-24)

[Roundeye]

My pressures are 28 LO and 256 HIGH. Here in LA (Lower Alabama;) ), we often stay around 96 to 98 and VERY high humidity. With these pressures, mine puts out 35 to 40 deg F at the vents.

 

as GD says, sometimes it will "cycle".

 

This happens when the superheat switch is actuated. This is in place to prevent your evaporator from freezing. It indicates that it's getting as cold as possible. Normally, like during really warm and hot days, it will run constantly. Our systems are expansion valve systems. A valve at the inlet of the evaporator meters the amount of coolant flowing through it dependant upun demand.

 

The other type is a CCOT (Cycling Clutch Orifice Tube) that has no valve. It uses a fixed orifice and accumulator on low side and cycles clutch dependant upon demand. Used in GM vehicles and some others.

[skishop69]

Yeah, I couldn't remember if it used a TXV or not. If it's overcharged and the TXV is freezing up, it will take a while to 'defrost' and let the compressor cycle again.

[bgd73]

I called an a/c expert at a radiator shop and was informed of some things...

The do it yourself bottles are at least 6% air and contaminate the system.The so called conditioners and sealers are bad as well for system, it gums things up.

It explains the long runs and not kicking back on again (the air is a spongy killer) even with the guage reading the system is full. So guages were correct, what I had in system wasn't.

The total cost for this is more than all other parts combined on my free loyale ---

$55 napa convert kit with a few bottles of 134a and retrofit

- that all leaked out when bad condensor revealed itself.

$22 for another bottle of 134a

- that all leaked out finding another bad condensor

$45 another condensor that worked

$14 conditioner and sealer

$75 more fluids to bring tight sytem back to full

-- system wasn't correctly filled with 134a

$125 quote to get it drained and refilled professionally

-- I truly don't even know how long system will hold it.

________

$336 total.

I am sitting next to my 12000 btu giant home a/c in my window for 6th year summer flawless running, for around the same price... Is my car's a/c worth it??

and to know the real hot weather is a rarity where I live, and doesn't last all that long.I will get it going however for the sake of "everything works":banghead:

Is there a better way than professional refill, and the diy bottles?

[GeneralDisorder]

Seriously - the so called "dirty" bottles are not that bad. If I ruin a compressor every couple years I'm fine with that. Used junk yard compressors are like $20, and the only other thing that would need replacement is the drier and maybe some of those switches. The drier I might get used, but then they are relatively cheap so might get a new one too. You can pull a vacuum on the system with some simple home made devices.

 

I just filled my system with some 20 year old bottles of R12 I had laying around. I replaced all the o-rings at every fitting point, and the system still had a tiny bit of pressure in it so I knew it would hold for a while. I get ice cold air now, and if it lasts for this season I'll call that good, and fix it if I need to next year assuming I'm still driving it. If it becomes more troublesome than replaceing some o-rings or the compressor then I'll use the windows instead - it's not that important, and definately not worth pouring more than a few bucks for refrigerant, or a spare used part into. I would rather spend a couple extra bucks on a stick of deoderant for my glove box.....

 

AC systems are not rocket science - especially these 20 yr old R12 setups - They are simple. Wire the damn compressor clutch to "ON" and it will run all day - might frost up a bit, but who really cares?

 

GD

[bgd73]

Seriously - the so called "dirty" bottles are not that bad. If I ruin a compressor every couple years I'm fine with that. Used junk yard compressors are like $20, and the only other thing that would need replacement is the drier and maybe some of those switches. The drier I might get used, but then they are relatively cheap so might get a new one too. You can pull a vacuum on the system with some simple home made devices.

 

I just filled my system with some 20 year old bottles of R12 I had laying around. I replaced all the o-rings at every fitting point, and the system still had a tiny bit of pressure in it so I knew it would hold for a while. I get ice cold air now, and if it lasts for this season I'll call that good, and fix it if I need to next year assuming I'm still driving it. If it becomes more troublesome than replaceing some o-rings or the compressor then I'll use the windows instead - it's not that important, and definately not worth pouring more than a few bucks for refrigerant, or a spare used part into. I would rather spend a couple extra bucks on a stick of deoderant for my glove box.....

 

GD

 

I guess I'll try for the bottles again...

This brings me back to a similar scenario on another car-- the diy bottles did not work on a super tight system. The pros that filled it took an hour and a half. This old sube seems to take it right in with pump on, so I'll go at it again. Is there a particular brand of refrigerant that is proven better?

I had 2 different 18oz bottles and one in particular did way more, proving there are differences of 134a.

[GeneralDisorder]

I guess I'll try for the bottles again...

This brings me back to a similar scenario on another car-- the diy bottles did not work on a super tight system. The pros that filled it took an hour and a half. This old sube seems to take it right in with pump on, so I'll go at it again. Is there a particular brand of refrigerant that is proven better?

I had 2 different 18oz bottles and one in particular did way more, proving there are differences of 134a.

 

I would just use the straight 134a - not the stuff with "sealant" in it. I would tend to fix the leaks and go with straight stuff rather than band-aid the system with some goop. I got a selection of o-rings from Autozone for $2.99 that took care of all the lines in my 86 sedan. Again tho - I used R12, so didn't need to vacuum my system as it was using the same as the original charge. I frankly have no idea how much I put in - approximately 24 - 28 oz I would say, but my charge line leaked a bit on the first two bottles (actually a LOT), and then I fixed it and put a whole third bottle in. It's cold, and that's all I care about, so I guess it's ok.

 

GD

[Roundeye]

No matter how much you put in or what brand, if it has moisture in the system it will never cool right. Replacing the reciever/dryer and pulling a vacuum on the system (boils out moisture) is the fix. Just something to consider if it constantly quits.

 

I converted mine from R-12 to R-134 along with several other people's cars with no problems. I've used Johnson's, Prestone, DuPont and Advance brands and all have worked well.

 

If you are not comfortable doing it yourself or lack the right equipment, then you must decide how important A/C is to you. Pay a shop:mad: or buy stuff to fix it.

 

Down here you would soak your seats with sweat without it. (the winters are nice though:D )

[rallyruss]

No matter how much you put in or what brand, if it has moisture in the system it will never cool right. Replacing the reciever/dryer and pulling a vacuum on the system (boils out moisture) is the fix. Just something to consider if it constantly quits.

 

I converted mine from R-12 to R-134 along with several other people's cars with no problems. I've used Johnson's, Prestone, DuPont and Advance brands and all have worked well.

 

If you are not comfortable doing it yourself or lack the right equipment, then you must decide how important A/C is to you. Pay a shop:mad: or buy stuff to fix it.

 

Down here you would soak your seats with sweat without it. (the winters are nice though:D )

 

this is verry true.

 

A/C systems when properly serviced will last a long time with out problems. If you do it half arse you will just do it over and over again.

 

the A/C tech yo uspoke with was dead on.

you need to pull a vacume on the system before charging or it will never last.

 

duel gauges are a must for those that understand how to read them.

 

the sealer is really bad stuff. it not only kills auto A/C systems but also the recovery machines at A/C shops.

 

you can decide what the best long term.

[bgd73]

this is verry true.

 

A/C systems when properly serviced will last a long time with out problems. If you do it half arse you will just do it over and over again.

 

the A/C tech yo uspoke with was dead on.

you need to pull a vacume on the system before charging or it will never last.

 

duel gauges are a must for those that understand how to read them.

 

the sealer is really bad stuff. it not only kills auto A/C systems but also the recovery machines at A/C shops.

 

you can decide what the best long term.

 

I suppose that would be final answer. I have learned on other cars the same thing with a/c. Once completely opened, it needs the pro the first time to clean it up and get it going, then going about recharges is ok on my own, or simple quick repair if I had to open. Swapping out condensor is a big move, and I had it out for awhile with open pipes just taped over. Oh well -- The most expensive a/c repair I have had yet.

Today will most likely be the only day at 90 with high humidity for rest of summer here -- but where I would like to travel to needs it.I found this cars interior to be one of the hottest especially out on the road (I have had 12 to conclude this:mad: ). I remember being at a stop in a traffic jam on a very hot day, high humidity, in an 87 DL with no a/c. I literally had to pull over and flop over in some shade first chance I got because of the ill heat. A/c was critical.. I swore to myself, even if I don't use it locally but for a hot month-- where I go to will.Just 200 miles south of my place is a different world of weather. Even my car reacts ill to it sometimes. Thanks for help.

[bgd73]

I think I've got it now... upon an internet site of diy a/c, I followed advice (I think it is too controversial to mention). I added 12oz over what oem states as full with a bottle. Now the clutch is doing something I am accustomed to on a low system -- a/c clutch engaging on and off quickly in a few second intervals. The diy bottles are a falsity to the amount of refrigerant they claim to have.also, when system is approaching "full" the bottles don't have enough on thier own to equalize a good reading, the site I found mentioned dipping can in a warm bowl of water while filling, and lo and behold it got it working better. Should I add one more 12oz? The quick on/off routine is as far as I have got to full automation. Before this last 12oz,I had to play with the switch in the car to get it going, then it would run a long time to frigid, then just shut off for at least 30 minutes or more, not wanting to stay engaged. It is definately a sealed system and clean enough -- watching sight glass clearly can tell you if theres a problem, mine is looking good at a shade to have plenty of oil/conditioners and no bursts of bubbles at all -- this is all I know so far.To add one more bottle or not is my big Q -- or if theres a prob with clutch quickly engaging and disengaging, would love to know the answer. I will post entirely the details if I get this going correctly DIY.