Do I need to change AC compressor for R-134A?

[Kommando]

I have been doing some research into this and have hit a wall. I have found lists of compressor part numbers that cannot be converted and ones to use if you have one of those. However the Bosch compressor I have installed is: 0 140 903 208 which I searched online and found this part number: 64 52 1 373 355. I don't see it on the list of non-compatibles, but want to be sure.

What I would like to know is if I can just use the retrofit kit and make sure there is enough oil in the compressor, or if I need to get: 64 52 8 363 550 or another conversionable one?

-Thanks

[warmsquash1]

Like anything, there's a right way, a wrong way, and a half-assed way. The wrong way is just topping off the oil and charging it with R134a (unless its already retrofitted which apparently isn't the case here). The right way is to completely flush the entire system, change the pressure switch, the dryer, and the compressor (if yours isn't compatible), sucking the system down to the correct inches of vacuum, put the correct amount of oil (PAG oil or esther oil usually) into the system, shoot some of the correct dye into the system (makes it easier to trouble shoot leaks later, just use a black light), and finally charging the system with the correct amount of R134a using a correct manifold assembly or A/C machine. The half assed way to do it (which I don't suggest or condone, but I've seen it time and time again) is to flush the system, change the dryer and switch, put the oil, dye and R134a in and call it a day. This way may last a couple of days or it may last years. Depends on the compressor. My thought is that if you're going to be in there anyways.... R12 and R134a run on different temperatures and pressures. There's completely different properties between the gases, so it's literally a completely different system. The store bought retrofit kits are only good for being able to utilize the factory lines with the different connectors that are necessary. They should be treated as a COMPONENT WITHIN a retrofit system, NOT an entire retrofit system. Just do us all a favor and don't use Propane... Believe it or not, I've seen it a few times and it scared the SHIT out of me when my machine started yelling four letter words....

[Kommando]

I got access to an AC machine and was planning on doing it the proper way, the kit I was looking at is from BMW with all the new fittings and O-rings. I have not looked at the drier yet, but will look into that.

-Thanks

[warmsquash1]

No problem. Hope all turns out well and you turn the dash into an ice cube machine. These cars cool veeeeeery well if done right and it sounds like you're on your way!

[Kommando]

Thanks again, just read your post again and missed the pressure switch.

The BMW bulletin and the write up I read forgot to mention the drier and switch. They basically say to evacuate the system, install kit, and fill with r-134a.

[Ryann]

Change your drier, locate and repair your leaks, pump down, and recharge with R414b. It is an R12 drop in, so no oil hassles, no expansion valve problems, no pressure issues.

[bmw325csi]

please elaborate, where can one get this refrigerant? Is it legal?

[Ryann]

Yes, it is legal, made by ICOR and also known as "Hot Shot". It is a drop in replacement for R12 refrigerant. It is compatible with all the existing components in the e30 R12 system including compressor oil. Both suction and discharge pressures will run very similar to the pressures you'd see in an R12 system, as opposed to the high head pressure we've been seeing in converted 134a e30 systems.

If you've got your EPA Certification it can be found at your local refrigeration supply wholesaler for about $250 for a 25lb jug. Any shop specializing in automotive A/C that doesn't have their heads up their asses will have it on the shelf as well. At one time it was available to the consumer in small sub-1lb cans, not sure if that is still the case. The problem with these is that it takes multiple cans to charge a system, so you risk system contamination during the can switch if you're not paying attention/don't know what you're doing.

[TrentW]

Like anything, there's a right way, a wrong way, and a half-assed way. The wrong way is just topping off the oil and charging it with R134a (unless its already retrofitted which apparently isn't the case here). The right way is to completely flush the entire system, change the pressure switch, the dryer, and the compressor (if yours isn't compatible), sucking the system down to the correct inches of vacuum, put the correct amount of oil (PAG oil or esther oil usually) into the system, shoot some of the correct dye into the system (makes it easier to trouble shoot leaks later, just use a black light), and finally charging the system with the correct amount of R134a using a correct manifold assembly or A/C machine. The half assed way to do it (which I don't suggest or condone, but I've seen it time and time again) is to flush the system, change the dryer and switch, put the oil, dye and R134a in and call it a day. This way may last a couple of days or it may last years. Depends on the compressor. My thought is that if you're going to be in there anyways.... R12 and R134a run on different temperatures and pressures. There's completely different properties between the gases, so it's literally a completely different system. The store bought retrofit kits are only good for being able to utilize the factory lines with the different connectors that are necessary. They should be treated as a COMPONENT WITHIN a retrofit system, NOT an entire retrofit system. Just do us all a favor and don't use Propane... Believe it or not, I've seen it a few times and it scared the SHIT out of me when my machine started yelling four letter words....

So I'm reassembling everything after retrofitting my wife's '88 Seta to R134a. I flushed the system and have installed a rebuilt Nippon Denso compressor, new rec/drier and expansion valve along with replacing every o-ring with new green ones. I already added ester oil to the compressor, rec/drier and condensor before I take it to my a/c guy this later week to get it vacuumed and charged. Will the vacuum suck out the oil I added or is it too heavy and just stays in the system?

[Ryann]

The vacuum pump will not suck out oil.

[Hellabad]

Change your drier, locate and repair your leaks, pump down, and recharge with R414b. It is an R12 drop in, so no oil hassles, no expansion valve problems, no pressure issues.

This ^^^

Or use R12.

R134 is a poor third choice.

Been there done that many times

[Ryann]

^I've tried to tell r3v this 200 times now but they won't listen. Maybe it seems too good to be true, idk.

[TrentW]

Assuming you have a working original R12 expansion valve...

[Ryann]

I have been repairing and recharging automotive A/C systems for years (admittedly primarily non-BMW) and have run into exactly ZERO faulty TXV's. Not to say it doesn't happen, but it usually isn't the cause of a system performance issue.

What does happen beginning with the use of synthetic lubricants associated with refrigerants like 134a and 404a is that high discharge temps. in the compressor tend to "cook" the oil turning it into a waxy substance that plugs up TXV inlet screens, resulting in the changing of the valve.

['e30love']

Yes, it is legal, made by ICOR and also known as "Hot Shot". It is a drop in replacement for R12 refrigerant. It is compatible with all the existing components in the e30 R12 system including compressor oil. Both suction and discharge pressures will run very similar to the pressures you'd see in an R12 system, as opposed to the high head pressure we've been seeing in converted 134a e30 systems.

If you've got your EPA Certification it can be found at your local refrigeration supply wholesaler for about $250 for a 25lb jug. Any shop specializing in automotive A/C that doesn't have their heads up their asses will have it on the shelf as well. At one time it was available to the consumer in small sub-1lb cans, not sure if that is still the case. The problem with these is that it takes multiple cans to charge a system, so you risk system contamination during the can switch if you're not paying attention/don't know what you're doing.

what kind of temperatures can be expected using this?