m800 AC retrofit and some questions

SirAlec · 24th May 2009, 00:49

i know exactly what you want man! but this car that i serviced also had it missing. So i posted the solution. please read the whole thread.

eternalck · 24th May 2009, 01:43

Quote:

Originally Posted by SirAlec

i know exactly what you want man! but this car that i serviced also had it missing. So i posted the solution. please read the whole thread.

yes i read it, and i have set it to a higher idle for the time the thing is fixed..i will post the pic even if you know the part required

.

eternalck · 24th May 2009, 15:59

One more serious issue? : I checked out the writings on the compressor and its written that its for the refrigerant type R12, while R134a gas has been filled.
Will this cause problems? My problems seem to be on the increase. Please help me out guys.... I am even not sure whether the proper oil has been filled with the gas.

SirAlec · 24th May 2009, 16:40

Quote:

Originally Posted by eternalck

One more serious issue? : I checked out the writings on the compressor and its written that its for the refrigerant type R12, while R134a gas has been filled.
Will this cause problems? My problems seem to be on the increase. Please help me out guys.... I am even not sure whether the proper oil has been filled with the gas.

I have done the same. But you have to completely drain the r12 gas. I changed the reciever dryer to a brand new one.

eternalck · 24th May 2009, 16:45

thanks for the quick reply SirAlec, Yes the receiver dryer is of r134a type. but isnt there oil in the new compressor which was meant for use with r12 gas or they have to add oil at the time of setup and there is no oil inside the new compressor?

and i still couldn't make it to the person for the picture..:(

SirAlec · 13th June 2009, 01:13

these two arrived. where can i send them. not shinny but its working.

m800 AC retrofit and some questions-p1060991-medium.jpg

m800 AC retrofit and some questions-p1060990-medium.jpg

eternalck · 21st June 2009, 16:29

@SirAlec sorry i did not read your reply, i was out of the city for some time...

i see that you misunderstood the part i was talking about. the part that was missing was the one where this part that you pictured above, is supposed to be fitted on the carb. :( Sorry for making you go through any trouble man.

I had a mechanic change the 'butterfly' of the carburettor from another engine and on it was the missing part.the part you pictured above is now fitted on the carb, and it is working flawlessly.

Well, the not cooling during the afternoon issue is now even worse and i am sweating it out in the heat everyday.
i had the ac checked up at a good workshop and they said that the pressure on the low pressure side is at 60-70 psi while it should be at about ~40. and that this was because the condenser was not being cooled properly (it has been mounted in the front). they say that the solution to this problem is to have a bigger condenser fitted at the rear of the car with a separate fan.

so is this really the cause and the solution to this problem?? please help me out guys :(

anupmathur · 21st June 2009, 18:37

Eternalck, I just read through this thread.
Seems to have been all 'jugaad' that has been done!

First, compressors are designed to work with a specific refrigerant. Filling R134a in a compressor designed for R12 is a very questionable (read wrong!) practice.

R134a works at higher discharge pressures. Even if the compressor can cope with this, what it means is that cooling is going to be poorer, especially at low engine rpms!
Secondly, the oil required for R12 is mineral oil, whereas R134a requires a synthetic lubricant!

I cannot see why R12 was not used in the first place.? A little difficult to procure but the country has a lot of old R12 machinery still in service.

Now that the job has been 'done', at least make sure the correct oil was filled in the compressor, else premature failure of the compressor is almost certain!
Even after you are able to fit an FICD relay the cooling is going to be poorer compared to what R12 would provide.

All the best!

eternalck · 21st June 2009, 23:52

thanks for going through the thread anupmathur, but then why on earth are these conversions so common all over the world. everywhere i asked, they said that its the same compressor with different valves. in fact the other person, (who got me into this mess), and had his car fitted with the same kit, is quite satisfied with it, but i'm yet to check it out for myself.
and the most interesting point is that all the ac workshops, even some trusted ones are telling me that the equipment is fine and provides the usual chilling that sanden is famous for on the m800, and this will be achieved after the rear shift of the coil.

i am not saying that you're wrong, because i know you're correct with the discharge pressure difference, and i'm gonna meet up with the installer soon confirm what oil he puts into the systems he installs and give him a piece of my mind too on whats happening...

eternalck · 22nd June 2009, 00:01

and now after putting some more gas in the system, the cooling has dropped in even normal heat. which makes a question bump into my mind, is it possible that the system has already been overcharged which is why there is high pressure on the low pressure side??

i also learned, that you need to have 85% of the amount of r134a in the system as much r12 would have been required. from what i know, the installer emptied a whole new can of the refrigerant into the ac when he charged it for the first time. i am unsure of the amount of gas in that can, but i can post it here after i meet him, or maybe if some of you might know about these cans then you might help me out here.

SirAlec · 22nd June 2009, 00:28

i pmed you!!

eternalck · 22nd June 2009, 01:45

did you send one more?? i did not get it then... i've replied to the first one.

and i think my problems have now intensified somewhat, look at this please Sanden USA: Compressor Refrigerant Oil, the page says that oil is already factory filled in the sd507 with that compliant with r12

what the hell should i do now

my head is spinning...

eternalck · 22nd June 2009, 02:12

should i just demand my money back... at least 75% and he take his stupid 'ac'??

anupmathur · 22nd June 2009, 08:47

Eternalck, AC systems are designed with matched capacities for the compressor, condenser, expansion valve and the evaporator.

You'd need to find out what size components are fitted in your car and whether these are suitable for R134a refrigerant. If they are, they should certainly also be fine for use with R12.

Ideally, you'd shift to R12. That means dumping the complete gas charge, including the compressor oil and then doing a fresh charge with R12 and the appropriate oil.

And yes, it does seem like the system is over charged currently. It is important to charge only the specified quantity of refrigerant into a system, else cooling degrades drastically.
The compressor can also suffer damage due to very high discharge pressures!

anupmathur · 22nd June 2009, 09:28

Quote:

Originally Posted by eternalck

....., and this will be achieved after the rear shift of the coil.

There is merit in what they are saying. A larger or more efficient condenser will help to a significant degree.
It is important to know the type of evaporator/expansion valve that has been fitted in your car. Is it designed, capacity-wise, for deploying with R12 or R134a?
When you say 'rear shift' of the condenser, where exactly is it going to be located? You should not lose the 'ram' effect of oncoming air with the vehicle travelling at normal speeds.

24th May 2009, 00:49	#46
SirAlec Senior - BHPian Join Date: Sep 2006 Location: zxc Posts: 3,395 Thanked: 727 Times	i know exactly what you want man! but this car that i serviced also had it missing. So i posted the solution. please read the whole thread.
	() Thanks

24th May 2009, 15:59	#48
eternalck BHPian Join Date: Nov 2008 Location: New Delhi Posts: 175 Thanked: 94 Times	One more serious issue? : I checked out the writings on the compressor and its written that its for the refrigerant type R12, while R134a gas has been filled. Will this cause problems? My problems seem to be on the increase. Please help me out guys.... I am even not sure whether the proper oil has been filled with the gas.
	() Thanks

24th May 2009, 16:45	#50
eternalck BHPian Join Date: Nov 2008 Location: New Delhi Posts: 175 Thanked: 94 Times	thanks for the quick reply SirAlec, Yes the receiver dryer is of r134a type. but isnt there oil in the new compressor which was meant for use with r12 gas or they have to add oil at the time of setup and there is no oil inside the new compressor? and i still couldn't make it to the person for the picture..:(
	() Thanks

13th June 2009, 01:13	#51
SirAlec Senior - BHPian Join Date: Sep 2006 Location: zxc Posts: 3,395 Thanked: 727 Times	these two arrived. where can i send them. not shinny but its working.
	() Thanks

21st June 2009, 16:29	#52
eternalck BHPian Join Date: Nov 2008 Location: New Delhi Posts: 175 Thanked: 94 Times	@SirAlec sorry i did not read your reply, i was out of the city for some time... i see that you misunderstood the part i was talking about. the part that was missing was the one where this part that you pictured above, is supposed to be fitted on the carb. :( Sorry for making you go through any trouble man. I had a mechanic change the 'butterfly' of the carburettor from another engine and on it was the missing part.the part you pictured above is now fitted on the carb, and it is working flawlessly. Well, the not cooling during the afternoon issue is now even worse and i am sweating it out in the heat everyday. i had the ac checked up at a good workshop and they said that the pressure on the low pressure side is at 60-70 psi while it should be at about ~40. and that this was because the condenser was not being cooled properly (it has been mounted in the front). they say that the solution to this problem is to have a bigger condenser fitted at the rear of the car with a separate fan. so is this really the cause and the solution to this problem?? please help me out guys :(
	() Thanks

21st June 2009, 18:37	#53
anupmathur Senior - BHPian Join Date: Sep 2007 Location: New Delhi Posts: 3,095 Thanked: 311 Times	Eternalck, I just read through this thread. Seems to have been all 'jugaad' that has been done! First, compressors are designed to work with a specific refrigerant. Filling R134a in a compressor designed for R12 is a very questionable (read wrong!) practice. R134a works at higher discharge pressures. Even if the compressor can cope with this, what it means is that cooling is going to be poorer, especially at low engine rpms! Secondly, the oil required for R12 is mineral oil, whereas R134a requires a synthetic lubricant! I cannot see why R12 was not used in the first place.? A little difficult to procure but the country has a lot of old R12 machinery still in service. Now that the job has been 'done', at least make sure the correct oil was filled in the compressor, else premature failure of the compressor is almost certain! Even after you are able to fit an FICD relay the cooling is going to be poorer compared to what R12 would provide. All the best!
	() Thanks

21st June 2009, 23:52	#54
eternalck BHPian Join Date: Nov 2008 Location: New Delhi Posts: 175 Thanked: 94 Times	thanks for going through the thread anupmathur, but then why on earth are these conversions so common all over the world. everywhere i asked, they said that its the same compressor with different valves. in fact the other person, (who got me into this mess), and had his car fitted with the same kit, is quite satisfied with it, but i'm yet to check it out for myself. and the most interesting point is that all the ac workshops, even some trusted ones are telling me that the equipment is fine and provides the usual chilling that sanden is famous for on the m800, and this will be achieved after the rear shift of the coil. i am not saying that you're wrong, because i know you're correct with the discharge pressure difference, and i'm gonna meet up with the installer soon confirm what oil he puts into the systems he installs and give him a piece of my mind too on whats happening...
	() Thanks

22nd June 2009, 00:01	#55
eternalck BHPian Join Date: Nov 2008 Location: New Delhi Posts: 175 Thanked: 94 Times	and now after putting some more gas in the system, the cooling has dropped in even normal heat. which makes a question bump into my mind, is it possible that the system has already been overcharged which is why there is high pressure on the low pressure side?? i also learned, that you need to have 85% of the amount of r134a in the system as much r12 would have been required. from what i know, the installer emptied a whole new can of the refrigerant into the ac when he charged it for the first time. i am unsure of the amount of gas in that can, but i can post it here after i meet him, or maybe if some of you might know about these cans then you might help me out here. Last edited by eternalck : 22nd June 2009 at 00:09.
	() Thanks

22nd June 2009, 00:28	#56
SirAlec Senior - BHPian Join Date: Sep 2006 Location: zxc Posts: 3,395 Thanked: 727 Times	i pmed you!!
	() Thanks

22nd June 2009, 01:45	#57
eternalck BHPian Join Date: Nov 2008 Location: New Delhi Posts: 175 Thanked: 94 Times	did you send one more?? i did not get it then... i've replied to the first one. and i think my problems have now intensified somewhat, look at this please Sanden USA: Compressor Refrigerant Oil, the page says that oil is already factory filled in the sd507 with that compliant with r12 what the hell should i do now my head is spinning...
	() Thanks

22nd June 2009, 02:12	#58
eternalck BHPian Join Date: Nov 2008 Location: New Delhi Posts: 175 Thanked: 94 Times	should i just demand my money back... at least 75% and he take his stupid 'ac'??
	() Thanks

22nd June 2009, 08:47	#59
anupmathur Senior - BHPian Join Date: Sep 2007 Location: New Delhi Posts: 3,095 Thanked: 311 Times	Eternalck, AC systems are designed with matched capacities for the compressor, condenser, expansion valve and the evaporator. You'd need to find out what size components are fitted in your car and whether these are suitable for R134a refrigerant. If they are, they should certainly also be fine for use with R12. Ideally, you'd shift to R12. That means dumping the complete gas charge, including the compressor oil and then doing a fresh charge with R12 and the appropriate oil. And yes, it does seem like the system is over charged currently. It is important to charge only the specified quantity of refrigerant into a system, else cooling degrades drastically. The compressor can also suffer damage due to very high discharge pressures!
	() Thanks