Air Conditioning Tech Thread.

[Rhyno]

Yes most refrigerants have a "smell" added to them to help prevent suffocation. Such as all the Hychill refrigerants and LPG for example.

[Rhyno]

Hey Z2TT,

That Merc Evap u where talking about earlier, is that the same model that uses the suction line to chill the fuel line before it enters the pressurised rail?

Heard of this but never found a Merc with it... would love to eyeball/play with one

[Z2TT]

W124, Never heard about it using the low pressure line to cool the fuel rail, why is there need for such feature? And you would need to have the a/c on all the time to cool your rail.

[Rhyno]

Hi,

Got told about the Merc set up when I was waaaaay back in trade school from my uni lecturer (who I now work with as it so happens lol) and it was a way off Mercedes acheiving better polution control from better atomisation, and also giving the car a little more omph when the ac is on; as I understand it and recall correctly...

Yes the ac had to be on, and yes it made the ac work harder, but still an interesting idea.

I have played around with fuel chillers when I was an apprentice, and they are great fun for red light racing, but have little value for constant WOT, as the fuel passes through the chiller too fast to have much effect. I used to have a ST141 2SC Corona, and the best it could do (in regards to statics) was a 2nd gear burnout. After fitting the chiller, it could hold 3rd gear to 110kmh!

Anyway im going off the point of this thread, was just thinkin, would love to get my hands on a Merc set up to play with in my Toymotor

[CrUZida]

Fuel chillers don't do much on EFI vehicles (with a fuel return line), as the fuel flow is about a billion times more than carby cars.

[Rhyno]

Yeah I had that thought Cruzida,

Got a RT132 'Rona that im putting an 18RG into, thought it might be a bit off fun, since it is still carbied.

Ryan

[matty12]

The lastest gas that will be used hfo1234yf or something along those lines is flammable. It will be the new replacement for R134A, new euros are the first to use it.

some stuff here about it
http://www51.honeywell.com/sm/lgwp-u...e_document.pdf

[CrUZida]

Any idea why they don't use R410 like you do in housing/commercial aircons?

[Grega]

OK i'll post here given people who are discussing know what they are on about. i've a 1995 EF Fairmont.......and the AC works when its gassed, works for a few months then dies. If I get it regassed - works OK for a bit, dies a few months later. Suggest to say it has a leak. It has a dye in the system but there is no dye leaking anywhere that I can see. I know inside the car it absolutely STINKS and i get the impression that in the HVAC box inside the car the last time I had it gassed, there was fluid floating around in there (hence the now rotting smell)

the AC place i took it too seems to think the whole dash has to come out and i'll looking at over 1k to fix this issue. apparently it was a known issue in Fords back then? something to do with incorrectly sealing o-rings...?

Any ideas or things I can check to identify the root cause - happy to take the dash out to find it.

[CrUZida]

Take the dash out (or at least the bits required), and remove the evaporator.

Then get the evap pressure checked as it probably has a leak.

Not sure if it can be repaired (depends where the leak is), and sometimes getting a 2nd hand unit is just as risky, but NFI what a new one would be worth!

[Grega]

whole dash out to get evap out crUZida
not pleasant
ah well has to be done. dying without AC over here melb although its raining more than hot over ere.

[matty12]

the falcons are quite easy in terms of pulling the dash out. Pretty much pull out the consloe and the whole dash, gauges, stereo comes out as one. Pop the glove box out and pull the fan speed resistor out and have a look in you can see the evap from there. Its a big silver box between the fan assy and evap on the fairmonts.

The ea-ed where more common for the evaps to leak, ef-el where the condensors.

There is no orings inside the hvac the tx is external, the evaps just leaked.

[Rhyno]

Any idea why they don't use R410 like you do in housing/commercial aircons?

It runs at Extremly high pressures (3000kpa discharge), and needs thicker piping for a start. Plus like most refrigerants it is a mixture of several refrigerants combined, and they evaporate at different rates. If you get a leak, even a small leak, the refrigerant in the blend that boils off the easiest will disappear first, and leave the whole charge useless. Less than ideal for regular leaks in auto ac systems. Personaly, i hate the shit, you always get lose oil whenever you have to disconnect from a system, no matter how much you try.

That Falcon definatly has a leak... are you using a UV light when your searching mate?

Kind Regards,

Ryan

[Grega]

thx matty for that - will start looking.

ryan - no not using UV light....better get a black globe didn't realise u needed one!

[allencr]

...in the HVAC box inside the car the last time I had it gassed, there was fluid floating around in there...

The evaporator's drain must have been clogged. Any sign of oil around it is from the evap. leaking.