Air Conditioning Tech Thread.

[Burgzz]

Hi all,
Not sure if this has been talked about or not, shoot me in the right direction if has thanks

I really have no idea what i need so hopefully someone can help;
I am fitting A.C to a 1977 ra23 celica. I have the factory fit box that goes under the dash and a condenser? (radiator looking thing that goes up front) that needs re-coring and thats about it...
What sort of pump etc etc should i get?

help would be much appreciated

Ed

[Rhyno]

Hi Ed,

Do you have an 18r engine in there?

Well you have managed to get the hardest part, the underdash evaporator, so it should be easy from here. Do you have the TX valve that go's with it? The next step would be to get the compressor, brackets and lines, best bet would be get an 2nd hand one with the brackets. I believe any 18r engine with an ac compressor will suit. After this it will just be a matter of replacing any damaged parts and you should be on the home straight.

If you want to go brand new you should be able to just will cost more but will work better. I did some googling for you, make sure you check your part numbers though if your interested: Car Part Wholesale - Auto Parts and Accessories Catalog - Replacement Toyota Celica A C Compressor

Here is a link to a page where this has been discussed in more detail: http://www.toymods.org.au/forums/tec...18rg-ra23.html

[Burgzz]

Yeah got an 18R-C

eerrmm i didn't see a TX valve on the system where i got the evaporator from, but ill have another look when I'm back home.. I'm guessing this is an important bit to get if i don't have it? haha
Yes i have all the brackets i should need because i have a wreck with a.c fitted to it, but i was wanting to make my system a more modern version with a rotary compressor..

So on that website would any of those compressors suit what i need, just have to change the pulley to suit a single V-belt...
Are there lots of different options for compressors, reciever/drier, and TX valves... If so what would be the best ones do you think?..

And thanks heaps for the help, can't wait to get it done... Fingers crossed before summer really kicks in haha

[Rhyno]

Hi Burgezz,

Sorry for the late reply have been away on work.

Yeah a tx valve is needed, unless you want to play around with capillarys or oriface plates. This should be a link to a new one, can any one confirm if this is the correct part number? 1977 Toyota Celica Climate Control Parts - PartsGeek

Unfortantly "retro teching" the ac compressor can be a bit off a PITA. Not all Compressors have the same style of connection, in relation to their refrigerant lines. Plus you really need to know the specs of your old comp, before you can begin hunting. Things you would need to find out would be, what sort of oil the AC uses, what type of shaft/pulley arrangement (so you can reuse your pulley), and also the capacity of your compressor.

Personally, I would just get the old ac fixed up. I have been in 3 differnt cars with AC running an 18r, a hilux 2 door, a corona station wagon and a sedan. All had stock parts, all 20+ years worn and all had good ac (after I played with them). The only one which really struggled was the Corona wagon, and that is due to it having such a large cabin. Once that wagon had its windows tinted it was a very comfy and fun car to drive. And this is in the Darwin heat...

Just my 2 cents

[CrUZida]

Just my 2 cents here.
Before you get any aircon system regassed, pull the evaporator out from the cabin and clean it!
If it hasn't been done in the last 5-10 years (chances are it hasn't) and the car doesn't run a cabin filter (chances are it doesn't), then the evaporator is probably covered in crap and would be running at a fairly low efficiency compared to when it was new.

I've made a habit to do this to all of my cars before getting them regassed, and the difference in some cases has been phenomenal.

[matty12]

yes very good idea, nothing like 20years of cat hair build up to spoil your cools.

[Rhyno]

I completly agree, condensors and evaporators should be cleaned whenever possible, they are both heat exchangers and require the most servicing out of any part in an ac or refrigeration system.

I use Condensor Cleaner on evaps, just make sure you flush it well.

[CrUZida]

Here is a photo of mine before, didn't get a pic after, but it was much much cleaner.

[maccac__1590]

dam thats some nice blockage^^ i had simmilar in my corona + a huge ass mice nest in the blower fan assembly, took soooooo long to clean out and get the smell out, one 2nd hand compressor and it worked for 2 months, compressor failed, new compressor from ebay america for 200 bucks landed at my door and it went for another 2 months then the condensor started to leek.............. picked up a brand new condensor for $75!!!! but the guy i got it of reccons there must be heaps sitting around on a shelf somewhere and they keen to get rid of them so they dropped the price heaps, i suppose there not many other idiots out there looking to fix a rt142 corona's air con haha,

so if anyone is looking for a obscure a/c part it might just be worth the call to find out if is available new and how much

[maccac__1590]

Hychill HR12 (Now called Minus30) is a great refrigerant

i would be interested in getting some to re-do my car/s and plus i have a few mates who are bugging me to do there car, just wondering how you go on a oddball stem, for example one of dads mates wants me to gas his system in a valiant ute with a universal evaporator under the dash, and cause the rest is custom do i just gas with pressures?? as i would with 134a? or should i look for different pressures??

[Burgzz]

Just given an update on how I'm going with it all.

Went to a place near my old mans work in seaford, the guy there has been a great help and I've got a compressor.
Had a mate help me make up new brackets to hold the new condensor
Got brackets off a mate in a whole lot of parts for the compressor which i only have to make up adaptor plates and its all done. Ill get pics when its all done
Then give it back to the guy at seaford radiators for him to put all the pipe work in..

Thanks again for the help Rhyno, is much appreciated.
And yeah Cruzida i cleaned that all out when i took it out of the wreck i have, Definitely was no where near as bad as that though, haha.

[Rhyno]

Gay, the internet just ate my F^&*ing post!

Your welcome Burgzz, glad to help. When you have it all done you should take a measurement of your ambient temperture and your vent temps for others to reference

@ Macca

Just make sure the systems are compatabile with HR12 (most are, you may need to change oil in your comp and change your drier) then using a pressure temperture chart (like this one http://www.hychill.com.au/pdf/hcm_e.pdf) just charge the system up until you have 270 kpa on your suction side.

Hope that helps, let me know if you need to know more

[maccac__1590]

ahhh it all makes sense now, its fairly close to 134a looking at that, sounds like i had better get my ass into gear and buy some, anyone recommend a dealer for qld?

[CrUZida]

Yeah, R134A has a pressure only a few psi higher than R12/HC12.
A pressure difference not worth worrying about.

[Rhyno]

The pressure difference is worth worrying about, if you charge a HR12 system up to 200kpa your evap will be at -6 C, which greatly increases the chance of the Evap icing up and blocking, and may also cause liquid flood back to the compressor which can be fatal e.g. the compressor trys to compress liquid refrigerant instead of vapor, as it has not fully evaporated back to vapour from a condensed liquid.

This would be like switching to methanol on a petrol motor and not adjusting the tune - it will work but not well.

Just charge to 270 kpa on the suction side and your will be fine.