R12 A/C regassing

[love ke70]

bugger all gas, and i wouldnt think its any more flammable than the next gas your putting in?
its not legal, as the lines enter the cabin dont they? cant have an LPG line run through the cabin.
but thats more a technicality as thats for dedicated flow lines from tanks etc, not just a little bit in an aircon line.

apparently it works wonderfully and needs no changes to the system.
but im no expert...

[Z2TT]

Hi,

There is no need for you to convert your system to R134a when there is allready drop-in alternatives that are more efficient than R134a. HC-12, OZ-12, there are many names given by many manufacturers but it is basically they are all Hydrocarbon based gasses. HC-12 (Hydrocarbon) is more refined than LPG as its purpose build, thus being more efficient. I have heard about Taxi drivers using this as a cheap alternative. An email I recieved from Hychil (Manufacturers of Hydrocarbon R12 Replacement gas) told me that LPG will work in R12 Systems but there are problems that arise in doing so, I will call them for more information.

As for those people thinking of converting to R134a, there are talks now of introducing new regulations to phase out R134a in automotive systems. R134a has a 0% Ozone Depletion rate, but has a high global warming potential, that is why they are looking for an alternative gas AGAIN.

It makes sense to use a drop-in alternative such as a Hydrocarbon gas for R12 systems that is proven to work, then have your car converted. Some people who have their R12 systems converted to R134a notice that their system doesn't cool as well, others don't notice a difference. This varies from car to car which have different condensor sizes, designs, aswell as airflow over the condensor. Some people will notice their R134a system cools just aswell as their old R12, however not on Hot days (40 degree's and over) and at low cruising speeds.

[Dale]

How much experience do you have with this stuff besides what you've read on the internet?

What happens if you have a head on accident when your AC system is charged with HR-12?

Sure it might cool great, and might be ideal for use in certain refrigeration systems... but maybe not for automotive use.

So... your points for using HR-12 is price and that it can drop straight into the system. Butane can do the same, and probably cost less than $10 to regas the system... why not regas it with butane?

[Z2TT]

I'd be more worried more about the petrol in your tank during a car crash then your air con gas. R134a and all air con gasses are flammable because of the oils they are mixed with in the system.

In the US they also sell DIY A/C Re-gas kits in R12 and R134a in disposable cans for cheap prices. I was about to buy one for $50 but customs will just throw it out.

[love ke70]

How much experience do you have with this stuff besides what you've read on the internet?

What happens if you have a head on accident when your AC system is charged with HR-12?

Sure it might cool great, and might be ideal for use in certain refrigeration systems... but maybe not for automotive use.

So... your points for using HR-12 is price and that it can drop straight into the system. Butane can do the same, and probably cost less than $10 to regas the system... why not regas it with butane?

how much experience do you have with this stuff? you seem to be implying your a fitter or have a much larger knowledge base on this matter than everyone else? if so, maybe you should share some info with us, rather than just coming off as a high and mighty preacher that gives no real info, only rhetorical questions that make you appear maybe more well informed than you are? maybe not...
i know i would love to hear just how much gas is in the system?
and to be honest, theres alot of other things id be worrying about before the volatile gas in my aircon system if i crashed.

[Dale]

how much experience do you have with this stuff? you seem to be implying your a fitter or have a much larger knowledge base on this matter than everyone else? if so, maybe you should share some info with us, rather than just coming off as a high and mighty preacher that gives no real info, only rhetorical questions that make you appear maybe more well informed than you are? maybe not...
i know i would love to hear just how much gas is in the system?
and to be honest, theres alot of other things id be worrying about before the volatile gas in my aircon system if i crashed.

Exactly what did I preach? I questioned someone's experience with a product they were preaching. If it's in his system and works great for him, then that's fantastic and I'm happy to hear about it. There's so much mixed information and a lot of ignorant opinions on AC gasses.

There has been threads about this stuff in the past, eg. the one with the video of what happens when they simulated a leak inside the cabin to see if it could ignite with a spark. This makes me question it's safety - to you and some others this may not be of concern, but to me it is. It would also be of my concern if a car ran into me and I was the one to reap the repercussions of someone being cheap on AC gas. (does anyone know where insurance companies would stand on the subject?)

I've had experience with r134a and have been a happy customer, there's plenty of accurate information on it out there, it's easy to come across, cheap, cools well and is happily supported by any auto ac place. Plenty of people in this thread, and every other thread on the subject are able to say the same thing... but very few people can actually chip in much information on how the hychill stuff runs in their system.

My opinion - it's cheap for a reason, and wasn't made the replacement for R12 for a reason. This also doesn't mean it's no good, it's just my opinion. It may cool fantastically and I'd like to hear how it goes for people and what the price difference is purely because there's so much mixed information on the subject and not many people have actually had experience with it.

[CrUZida]

Sure it might cool great, and might be ideal for use in certain refrigeration systems... but maybe not for automotive use.

This line here sounds more like a preach than a question.
Probably not what you were trying to get across though.

[HKS_TRD]

Interesting thread

When you get the drier replaced, do they use your existing lines?

I dismantled a system that I assume was R12 which worked fine till the last 2 years due to losing gas.

My car is in bits and I dont really want a freshly painted bay/car getting butchered by someone, so I was thinking I could have all the bits fitted while its still in primer if any fabrication needs doing then final fitted after and gassed when the car is running.

The area in an MA-70 where the drier sits is a little tight and one line is really long, so am curious, what is size difference between the driers for each system? And want to keep factory mounting setup if possible.

Picky I know but thats just me

[The Witzl]

they will use the original line, and just fit the new drier.
Sometimes they have to use adaptors to get the right fittings to match the drier, but this is no concern really.

Remember, most shops will do this on a hoist, so they'll probably remove the drier from the bottom of the car.

[BrianRA23]

I have the hydrocarbon HR12 in my car and price was not the deciding factor, after hearing how effective it was and that the cooling properties are similar to R12. This meant that the climate control system had a better idea of what to do and on a hot day there is cold air coming out the vents almost immediately, which impresses me every time. Duty cycle and load on the compressor is less.
The molecule size is larger on the HR12 and results in small leaks not being so much of an issue, which in addition to the lower pressures means you system will last longer.
R134a is not ozone friendly, just friendlier than R12

I had heard that if the R134a vents in your car it could make you unconscious quite quickly, so I did a search on the net. I found that during tests of various gases the R134a was the only test that was terminated early (at low concentration) and the person still had side effects (headaches 9 months later).

As we know hydrocarbons are flammable, but this product has been approved for use in automobiles.

I have a friend who insists on using R134a, and has read all the documentation to make an educated system. He claims that the recommended charge (in grams) for most systems is too high and results in the pressure being too high and less effective.

[Mos]

When you get the drier replaced, do they use your existing lines?

Are you thinking of the condensor being replaced?
The R/D is the round, can looking thing which is usually model specific and available in adundance. In parallel flow condensors the r/d is in one of the tanks, so not as easily visible.
If you're replacing the condensor, then you need to adapt it to the lines as usually the fittings and locations are likely to be different.

I have the hydrocarbon HR12 in my car and price was not the deciding factor, after hearing how effective it was and that the cooling properties are similar to R12. This meant that the climate control system had a better idea of what to do and on a hot day there is cold air coming out the vents almost immediately, which impresses me every time. Duty cycle and load on the compressor is less.

Could you please confirm what you mean here?
My understanding is that on toyotas the compressor is not controlled by the climate control setting. The A/C is always set to maximum cooling, with the duty cycle being determined by whatever parameters stop the evaporator from icing over - usually a specific air temp on the outlet of the evaporator - and the desired climate temperature is controlled by adding heat (I have not seen one toyota setup that does not do this - A/C is either on or off).

The molecule size is larger on the HR12 and results in small leaks not being so much of an issue, which in addition to the lower pressures means you system will last longer.

Does anyone have pressure figures?

R134a is not ozone friendly, just friendlier than R12

Agreed. There was a rumour that R12 was phased out not because it was "bad" but because someone couldn't make money off it anymore (the patent for its production ran out).

Mos.

[cambelt]

All the old 60,s and 70,s toyotas controlled the A/C pump via a ajustable thermostat .
It's such a inefiecient way to control temp by adding heat the way toyota climate control works ,
it may result in a more accurate temp but what about the poor A/C pump slugging it out 100% all the time .
I fit ajustable thermostats to cars that lock the pump on 100% with the A/C button on.
Dave

[CrUZida]

Does anyone have pressure figures?

I've been told R134A runs about 20psi higher than R12. 270-300psi is the normal operating range of R134A.

http://www.cygnusx1.net/Supra/Librar.../AC/AC_032.gif
According to this the high pressure cut out switch on the MA70 (R12) is 384psi.
The MA70 also has a high pressure switch to turn on its 3rd thermo fan (I'm guessing its around 270psi as the thermo turns on about 5 seconds after I turn the aircon on in my R134A regassed system, too low for my liking, but too late to change it).

[HKS_TRD]

Are you thinking of the condensor being replaced?
The R/D is the round, can looking thing which is usually model specific and available in adundance. In parallel flow condensors the r/d is in one of the tanks, so not as easily visible.
If you're replacing the condensor, then you need to adapt it to the lines as usually the fittings and locations are likely to be different.

Sorry I was meaning just the receiver dryer, I was wondering when changing it how many other modifications are required or will the new one for R-134 be just a direct bolt-in swap? I just imagined it was not going to be this simpe, as nothing it seems usually is!"

[wa5]

Just on the subject of older Air Conditioning units.... someone on another site (not Toyota related) stated that some older Toyotas (late 60s) came factory fitted with a "peltier effect" (thermolectric?) A/C system mounted under the rear parcel shelf... anybody able to confirm (or more probably) deny this rumour....

My guess is that the person is getting mixed up with early Crowns which may have come with the A/C in the rear shelf.... but still cooled by a compressor