Air COnditioner Gurus

[dumbdunce]

have a problem with charging up the air cond on my 80 Series ('96 HDJ) - on running, the compressor cycles and gets very hot, the air blows only slightly cool. at the sight glass can see plenty of yellow dye but it's hard to tell if it's liquid or gas behind there. on the high side gauge it cycles up to 3000kPa, where the high pressure switch shuts if off, takes about 10 seconds to come down to 2400kPa, where the switch allows the compressor to run - again for about 10 - 15 seconds. occasional bad vibes from the high pressure line running in to the evaporator (line with sight glass in it).

history: the air conditioner worked fine until the truck drove into a tree and ruptured the short line between the receiver/dryer, and all the gas escaped. The dryer has not been replaced but the system was nitrogen purged after fitting a new line, then vacuumed for about an hour, no leaks, should be no moisture in there.

ideas? is the system blocked? was the explosive decompression damaging to the expansion valve? is it perhaps overcharged?

any ideas?

cheers

Brian

[suzy]

i would guess from working on housing crap it probaly has a gas blokage in the tx valve,or are car air con capilarys (sp) i haven't done car air cons before but thats what i suspect.

[dumbdunce]

i would guess from working on housing crap it probaly has a gas blokage in the tx valve,or are car air con capilarys (sp) i haven't done car air cons before but thats what i suspect.

tx I think - yes that is what I think it is too :( so probably have to pull the evaporator unit? is it likely to be cleanable/servicable or will it need replacing?

[RV80]

the tx valve.

I would say this is the problem also. I know on commodores the TX valve caused the high pressure hose to vibrate at idle.

[Screwy]

if you have to open the system to air, the drier must ALWAYS be changed.
if will be stuffed....

also your TX valve sounds like it could be playing up also....

with regards to the gas in the sight glass... if u can see it its liguid.... gas doesnt show up as u cant see it.

also, where the sight glass is should be on the liquid line which means it should be liquid anyway.

screwy

[suzy]

then vacuumed for about an hour, no leaks, should be no moisture in there.

when you evac the system you should have a minus reading on the low pressure gauge,i can't remember how low to evac it but the longer doesn't meen better,same as charging the system,if there's to much gas it will ice up an hydraulic lock the kompressor,when we do house air cons we put a tonger (sp) on the kompressor and measure the current draw,we do this because air cons run in different ambient tempertures all over the world and have different loads on the kompressor, so a set gas pressure setting isn't possible,

[ozy1]

what refrigerant are you using on this? with that year model, i assume its R134a, what is your suction pressure readings?

one other thing, that will help a diagnosis, could you take a preassure reading, first thing in the morning, with engine off, and also tell us the ambient Temp, at that same time,

this will help, as there may be non condensables in the system, thus making pressure higher,

[suzy]

i haven't touched an aircon for a while but i heard that sp34e is the go.

[ozy1]

i haven't touched an aircon for a while but i heard that sp34e is the go.

all cars i have seen run R134a from the factory, not 100% sure, but the sp34e may be a drop in replacement, but at a guess, i hink he will be running R134a

[Tojo]

do you have an ARCTIC licence?

[suzy]

do you have an ARCTIC licence?

nope mine was RACIRB (Refrigeration Air Conditioning Industry Registration Board)



whats ARCTIC

[Tojo]

http://www.deh.gov.au/atmosphere/ozone/ ... c-faq.html
http://www.arctick.org/index.php
have a look at those links.

Any person who handles refrigerant gases where there is a risk of emission (either ozone depleting substances or synthetic greenhouse gases) will require a national Refrigerant Handling Licence. These gases include refrigerants such as R12, R22, R134a and R410a. Any technicians who, for example, decant or reclaim gas or decommission or install systems will be required to have a licence. Handling refrigerant gases without a licence will be an offence.

i would suggest if you are not accredited and licenced not to touch anything related to refrigeration or airconditioning.

[dumbdunce]

http://www.deh.gov.au/atmosphere/ozone/ ... c-faq.html
http://www.arctick.org/index.php
have a look at those links.

Any person who handles refrigerant gases where there is a risk of emission (either ozone depleting substances or synthetic greenhouse gases) will require a national Refrigerant Handling Licence. These gases include refrigerants such as R12, R22, R134a and R410a. Any technicians who, for example, decant or reclaim gas or decommission or install systems will be required to have a licence. Handling refrigerant gases without a licence will be an offence.

i would suggest if you are not accredited and licenced not to touch anything related to refrigeration or airconditioning.

so you need accreditation and a license even to turn an air conditioner on?

relax, I have a fridgie mate working on it, I am just watching. He is more experienced in industrial systems hence the questions.

[kingchevy]

It annoys me seeing people still trying to attempt air-conditioning without a license after all the rubbish people that deal with it have to go through. But I suppose they may not know since they arent actualy in the industrie

[dumbdunce]

what refrigerant are you using on this? with that year model, i assume its R134a, what is your suction pressure readings?


one other thing, that will help a diagnosis, could you take a preassure reading, first thing in the morning, with engine off, and also tell us the ambient Temp, at that same time,

this will help, as there may be non condensables in the system, thus making pressure higher,

it is 134a. suction reading is low (lower than it should be), but I can't remember how low. will give it another fiddle this afternoon.

[kingchevy]

That brings up another pet hate the guy who is a "fridgie" doing car air conditioning obvisouly he has no idea about and r134a system or else he would know to change the reciver drier if you leave the reciever drier out to the atmosphere then it will get moisture in it and can possibly fall apart inside the system when its regased and completely block the tx and condenser that may be what has happened to youre system if you had of payed a proffesional who charges reosonable then you could have been out of this for a few hundred dollars with warranty and the reasurance that its working the best it can. anyway sorry to bitch.

[dumbdunce]

It annoys me seeing people still trying to attempt air-conditioning without a license after all the rubbish people that deal with it have to go through. But I suppose they may not know since they arent actualy in the industrie

relax, read above. I have a licensed guy doing the work.

At the risk of hijacking my own thread, have you ever changed a tap washer? done any mechanical work on any vehicle other than your own? changed a light switch or a power point? these all put you in the same boat as doing ac/fridge work without a license. which I am not. I don't have the skills and I don't have the gear. if you have nothing constructive/helpful to add then please, don't say anything at all.

[bluemq]

That brings up another pet hate the guy who is a "fridgie" doing car air conditioning obvisouly he has no idea about and r134a system or else he would know to change the reciver drier if you leave the reciever drier out to the atmosphere then it will get moisture in it and can possibly fall apart inside the system when its regased and completely block the tx and condenser that may be what has happened to youre system if you had of payed a proffesional who charges reosonable then you could have been out of this for a few hundred dollars with warranty and the reasurance that its working the best it can. anyway sorry to bitch.

One of my pet hates is aircon mechanics who think they can charge the world for what is a very simple system to diagnose. :p

[dumbdunce]

...he would know to change the reciver drier if you leave the reciever drier out to the atmosphere then it will get moisture in it and can possibly fall apart...

I rang and spoke to four or five "professionals" and only one of them insisted that the r/d had to be replaced, the rest assured me that it would be fine after purging and vacuum. Maybe the one was right, but my gut feeling is that it is only necessary to replace it if you're too lazy to propery purge and vacuum the system before charging. how exaclty does it fall apart? isn't EVERY r/d exposed to the atmosphere, if even only for a short time, when it is installed?

Since most "professional" car air conditioner people are usaully monkeys empolyed by auto electricians, with mo more experience or training than "open this valve and let the gas flow until the this gauge reads this much", having a fully trained, accredited and licensed fridgie working for me is quite comforting because I know he has a lot of experience on many types of systems and has years of trade training to back him up. He wants to start working for himself, including vehicle work, so he has to get some experience. We are helping each other out, the result is a win win situation - I get free work, he gets free experience, if we have to share the cost of a few parts to get it working, no big deal.

once again thankyou for your stirling advice on what I should have done - it is of absolutely no help in the current situation. All I want to know is (a) what might be wrong (b) how to fix it. If I had a time machine, I'd take your advice and take it to a "professional".

Now, if you have anything helpful to add (like, how to determine if it is the tx valve, and whether or not it is possible to clean/clear such a blockage without removing the evaporator unit) then fire away. otherwise please be quiet and let the helpful people say what they have to say. you might even learn something.

[suzy]

all talk about licences and stuff,

there must be a few engineers on here to do all their own 4by mods.

i am a refrigeration mech by trade,started when i was 16yo,finished at the ripe age of 20yo,went out on my own for a year and a bit,made good money like $700 aday,

then come all the sparkys that know it all and go and get there RACIRB and now they are fridgy's, because they are sparkys aswell they can do a complete install including electrical , pipe work and comisioning.
it piss's me off and most of the fridgys in perth becauce the sparky/fridgys are under charging to get the job.and the actual 4 year fridgys can't get the jobs because we can't do electrical.
other words sparkys leave the fridgy stuff to the fridgys and keep playing with wires.



back to the topic,
i remember flushing a system with Argon.?
can you get a current draw from the kompressor?
is the thermostat still in the right spot because you said the car had a knock on the frond end,maybe the thermostat has moved and is taking a reading of the evaporater not the air coming passed it?

[dumbdunce]

back to the topic,
i remember flushing a system with Argon.?

was flushed with nitrogen. any dry, inert gas should be ok?

can you get a current draw from the kompressor?

compressor is engine driven, the only curent it draws is for the clutch. it is working pretty hard (get hot, about 60 - 70C on the outside of the case) and just starts to slip the clutch before the over presure cutout.

is the thermostat still in the right spot because you said the car had a knock on the frond end,maybe the thermostat has moved and is taking a reading of the evaporater not the air coming passed it?

it wasn't that hard of a knock, the evap unit is pretty solid. I am pretty sure it is an over pressure shutoff, and not under temp. Gauge was reading 3000kPa at shutoff and 2400 at restart.

[suzy]

thats about all i can offer,

[ozy1]

alright,
first up, before you warm up the car, so there is no engine heat, put the guage on the system, and post up what the standing pressure is, and also, what the ambient temp is, then ill compare it to a chart, and determine if there are noncondensables in the system,

Then, depending on the outcome of that, we can move on to other areas,

[Screwy]

i haven't touched an aircon for a while but i heard that sp34e is the go.

all cars i have seen run R134a from the factory, not 100% sure, but the sp34e may be a drop in replacement, but at a guess, i hink he will be running R134a

all cars prior to approx 1991 ran R12 systems...........

SP34E is a drop in replacement to R12 if ever you need to charge a system up again on an R12 system that has had a leak.....

R134a is a new gas alltogether and is in all A/C in cars after 1992. When a car with the older r12 system ( early GQs and MQ etc patrols and similar aged cruisers and everything in 80s ) most workshops do a complete RETROFIT which they change TX valves etc etc etc to run R134a.

R134a will not run in an R12 system at alll without getting this retrofit done...... Sp34e is a drop in to an R12 system but is designed for houshold use, no workshops put it in... the wouldnt make any money

I have SP34e running in my 89 GQ system ( r12 system ) and works brilliantly.

screwy

[ozy1]

i haven't touched an aircon for a while but i heard that sp34e is the go.

all cars i have seen run R134a from the factory, not 100% sure, but the sp34e may be a drop in replacement, but at a guess, i hink he will be running R134a

all cars prior to approx 1991 ran R12 systems...........

SP34E is a drop in replacement to R12 if ever you need to charge a system up again on an R12 system that has had a leak.....

R134a is a new gas alltogether and is in all A/C in cars after 1992. When a car with the older r12 system ( early GQs and MQ etc patrols and similar aged cruisers and everything in 80s ) most workshops do a complete RETROFIT which they change TX valves etc etc etc to run R134a.

R134a will not run in an R12 system at alll without getting this retrofit done...... Sp34e is a drop in to an R12 system but is designed for houshold use, no workshops put it in... the wouldnt make any money

I have SP34e running in my 89 GQ system ( r12 system ) and works brilliantly.

screwy

now i have pointed it out, i left out one keyword from my post to mkae it right, the key word was newer, as we were talking about the 96 cruiser,

[dumbdunce]

alright,
first up, before you warm up the car, so there is no engine heat, put the guage on the system, and post up what the standing pressure is, and also, what the ambient temp is, then ill compare it to a chart, and determine if there are noncondensables in the system,

Then, depending on the outcome of that, we can move on to other areas,

standing pressure/ambient temp was ok (checked it last night) but can't remember the numbers now. pretty sure it is non-condensibles - have pulled the entire system apart this morning - high and low pressure lines, condensor blow through and there is no blockage of the TX valve or evaporator core.

11 minutes to get the evap unit out from under the dash - hooray Toyota designed something right for a change!

so, people who know - do I NEED to replace the receiver/drier, or if it is vacuumed down for long enough (12 hours? 24 hours?) will it be ok? If I need a new one do I get it from toyota or can they be bought over the counter aftermarket?

thanks all for actual help given so far!

[ozy1]

best bet is get a new drier, for what its worth, and for peace of mind,

[muzza_fattire]

back to the topic,
i remember flushing a system with Argon.?

was flushed with nitrogen. any dry, inert gas should be ok?

Nitrogen is not an inert gas.

[Tojo]

put it this way, if you dont get a new drier you really will live up to your name!!! go to lovelocks or ingrams and get a drier. Take the old one with you so you get the right sort. They are cheap, unless you have to pay full retail.

[dumbdunce]

back to the topic,
i remember flushing a system with Argon.?

was flushed with nitrogen. any dry, inert gas should be ok?

Nitrogen is not an inert gas.

there's always one

no nitrogen is not inert in the purest sense of the word, but for the sake of flushing and drying a refrigeration system, it is far less reactive than oxygen and much dryer than water and those are the things that do the damage and much cheaper than argon and it is what refrigeration mechanics use for such purposes.

thanks for another worthless addition to this thread.