R12 to R134a to R12 - Page 2 - PeachParts Mercedes-Benz Forum

leathermang · #16 05-20-2003, 02:17 PM

I think those are the total charge of refrigerant or the oil charge for individual compressors.... I think he is still searching for the total system oil charge chart...

Larry, it seemed like a lot for just the compressor... that is why I asked if it was for the system....but not much for the whole system...

engatwork · #17 05-26-2003, 01:17 PM

I converted the '85 300D from DuraCool to R12 on Saturday and got the a/c system going in the 240D yesterday. My procedures were the same on both cars. Took everything apart including removing the compressors. Drained the compressors (got less than 1 ounce of "green" lube out of them) and flushed everything except the dryers (they got replaced in both cases). After flushing I blew the lines out with compressed air and then during reassembly I added mineral oil to the compressor and poured it into the low pressure hose where it comes apart at the top of the engine. I put 8 ounces in the 240D and 7 ounces in the 300D based on information I got from ackits.com site. The oil capacity is different from what the Haynes manual says (5.80 ounces). If anyone feels I need to remove some please let me know and I will do it again. Anyway added some good old r12 until the site glass was clear and now both of these cars cool as well as the wifes 1997 Honda. WOWZER - I am SO glad to have a good working a/c in the 300D which is original black. You can tell by the attached photo that a black 300D in middle Ga is not something to take lightly.

engatwork · #18 05-26-2003, 01:38 PM

Forgot to mention - I did pull a vacuum for about 4 hours prior to putting the freon in

.

leathermang · #19 05-26-2003, 01:58 PM

I don't know if I was reading that too literally.... the "flushed everything except the dryers" part... but usually the compressors are not flushed with flush... it is more like Larry has described.... a 'rinse' with the new type oil, turning over by hand and emptying it... maybe half a dozen times.....
And also... the evaporator is often just blown out with Dry Nitrogen... as compared to putting flush liquid in it... because it is hard to get it all out without being able to turn it around... to drain it....

Jim, which compressor are you dealing with... the Delco seems to be different with respect to a crankcase reserve of oil .... I think all its lubrication is from the oil moving around with the lubrication... the advantage of that design is that it can be mounted in any plane.... you can't do that to a York.... only two directions they can be used...

engatwork · #20 05-26-2003, 02:03 PM

Greg - you are right. I should have paid more attention to what I posted. I did not flush the compressor nor the expansion valve. I removed the compressor, drained the existing lube, poured a little mineral oil in it and drained it again. Did this a couple times and then poured a couple ounces of lube in it and bolted it on.

leathermang · #21 05-26-2003, 02:16 PM

Great, just worried about other's impression of proper procedure...I figured that is what you did... Am really glad you have COLD air.... welcome back to the R-12 fold....

Plantman · #22 04-11-2005, 01:56 PM

Being a novice compared to you guys, is there any loss of the mineral oil during the vacuum?

boneheaddoctor · #23 04-11-2005, 02:23 PM

I am soon to be doing this.....to save the labor costs of a pro......anyone have a link showing exactly where all the locations of the O rings are.....

As I have never taken appart one of these systems I want to know where everything is....I want to flush it well...preplace al lthe old O rings evacuate the system...replace the dryer and recharge with R-12 assuming it has no leaks .....which if it does have I need to learn to troublshoot. I am going to try to get the certification so I can buy my own R-12 and see if I can't borrow the tools off someone.

I also would like to retrofit the W116 back to R-12 as it currently has R-134 in it and I am less that thrilled with its performance. But it is working at least....the W123 blows warm air and compressor isn't comming on...I assume its do to low collant pressure. I seem to have missed that when I looked at it when I bought it back in February.

#24 04-11-2005, 02:58 PM

Plantman,

The evacuation process removes no oil. The only way to get it out is to break all the connections and thoroughly flush it out. Why do you ask?

Bonehead,

I don't know where you would find a diagram, but it should be easy enough to find them. There will be four under the passenger side dash at the expansion valve. There will be two at the filter/drier. There will be two at the condensor connections. There will be two at the compressor manifold. Depending on the exact 123 you have, there may also be a connection between hose and pipe to the manifold that connects to the compressor. There also will be an o-ring on one of the sensors in the filter drier, the other is a temp switch with no fluid connection. It could be that some 123's have pressure switches for both sensors on the filter drier in which case there will be an o-ring on both of course.

Don't forget to rinse out the compressor with oil of the type that you will be putting out, DO NOT flush the compressor with solvent.

Good luck all,

boneheaddoctor · #25 04-11-2005, 03:04 PM

Quote:

Originally Posted by LarryBible

Plantman,

The evacuation process removes no oil. The only way to get it out is to break all the connections and thoroughly flush it out. Why do you ask?

Bonehead,

I don't know where you would find a diagram, but it should be easy enough to find them. There will be four under the passenger side dash at the expansion valve. There will be two at the filter/drier. There will be two at the condensor connections. There will be two at the compressor manifold. Depending on the exact 123 you have, there may also be a connection between hose and pipe to the manifold that connects to the compressor. There also will be an o-ring on one of the sensors in the filter drier, the other is a temp switch with no fluid connection. It could be that some 123's have pressure switches for both sensors on the filter drier in which case there will be an o-ring on both of course.

Don't forget to rinse out the compressor with oil of the type that you will be putting out, DO NOT flush the compressor with solvent.

Good luck all,

Well the under the hood stuff will be somewhat obvious.....the stuff hidden under the dash is what I was more concerned with...I want to do it right and not miss something....I also need to see how much needs to come out fo access to those.....thre is sooooooooooo many threads on the subject its very daunting to decide which ones to read and which ones to ignore.

leathermang · #26 04-11-2005, 03:04 PM

Assuming you pull your vacuum from the usual high locations of the valves there should be no loss of oil due to vacuuming.

Well, looks like Larry beat me to it...

If you contact Carlisle Auto Air ( do search for number ) they sell a set of green orings for the 123... that number has been posted with picture by me before.. it won't let me post things twice anymore.. even if I change the name on my computer...

Plantman · #27 04-11-2005, 03:06 PM

Quote:

Originally Posted by LarryBible

Plantman,

The evacuation process removes no oil. The only way to get it out is to break all the connections and thoroughly flush it out. Why do you ask?

Bonehead,

I don't know where you would find a diagram, but it should be easy enough to find them. There will be four under the passenger side dash at the expansion valve. There will be two at the filter/drier. There will be two at the condensor connections. There will be two at the compressor manifold. Depending on the exact 123 you have, there may also be a connection between hose and pipe to the manifold that connects to the compressor. There also will be an o-ring on one of the sensors in the filter drier, the other is a temp switch with no fluid connection. It could be that some 123's have pressure switches for both sensors on the filter drier in which case there will be an o-ring on both of course.

Don't forget to rinse out the compressor with oil of the type that you will be putting out, DO NOT flush the compressor with solvent.

Good luck all,

Larry, nice to hear from you and I hope all is well.

I was just curious how no oil is removed while you are sucking out moisture/oxygen. Just seemed odd that's all.

Now my new dilemma with the 240D is trying to figure out why the aux fan is not coming on when the ac is on. I gotta go get my r-12 guages and check it out.

I can only assume that the freon is a bit low. It'll freeze you out in the morning or at night, but not on a 90 degree day.

What should my pressures be on a 240D? Additionally, if the freon is low, would htat prevent the aux fan from coming on?

Thanks

boneheaddoctor · #28 04-11-2005, 03:06 PM

THat thread was fairly recent....I remember seeing it. I need to call some people to see who might have tools I can borrow.

#29 04-11-2005, 05:24 PM

Bonehead,

Under the dash, all the o-rings are at the expansion valve. Two of them on the pipes from the evaporator and one each on the hoses that come through the firewall to connect to the expansion valve. While you're there inspect the expansion valve closely. It has proven to be a common leak source for me. Maybe I've just been unlucky, but it wouldn't hurt to look it over well for an oily film. They tend to leak at the bulb on the end where it joins the block.

Plantman,

Yes, low freon will indeed result in the aux fan not coming on particularly in cooler weather. It is turned on by excessive high side pressure which you will not have, of course, if the system is low on refrigerant. By turning on the fan at excessive high pressure, you bring the pressure down, protecting the compressor. You can see this when your gauges are connected on a hot day. When the fan comes on the high side goes down rapidly.

Hope this helps,

boneheaddoctor · #30 04-11-2005, 08:56 PM

Quote:

Originally Posted by LarryBible

Bonehead,

Under the dash, all the o-rings are at the expansion valve. Two of them on the pipes from the evaporator and one each on the hoses that come through the firewall to connect to the expansion valve. While you're there inspect the expansion valve closely. It has proven to be a common leak source for me. Maybe I've just been unlucky, but it wouldn't hurt to look it over well for an oily film. They tend to leak at the bulb on the end where it joins the block.

Hope this helps,

Thanks...I will pull the kick panel and check that out in the next couple days....