Should I be adding compressor oil with my refrigerant? - Page 2 - PeachParts Mercedes-Benz Forum

leathermang · #1 02-26-2010, 02:54 PM

Quote:

Originally Posted by ah-kay

Some shops, Walmart included, sells a r134a can for 'high mileage' car. Basically, oil is mixed into the r134a already.

I must go and look at that..

that is pretty CRAZY , if true, since mileage on the vehicle has NOTHING to do with the condition of or the amount of the oil charge in the AC system....

Sounds like a recipe for people getting too much oil into their AC system.. then wondering why their Cooling Efficiency really declined...

rrgrassi · #2 02-26-2010, 03:10 PM

Lethermang: Here is the link to the company that sells the "high mileage" r134a...

http://efproducts.com/index.html

leathermang · #3 02-26-2010, 03:44 PM

WOW,

http://efproducts.com/proddetail.php?prod=340

Talk about bogus copy. That is so wrong on so many levels....
They are counting on the ' A fool born every minute' to make money.
Someone should file a complaint with the proper authorities....

JHZR2 · #4 02-26-2010, 04:27 PM

People wonder why their AC systems have so many issues.

Simple. Dont mix lubes, keep it clean and dry, and if the pressure is ever lost, if nothing else, evacuate the system and pull a long vacuum on it.

Run the AC often to keep seals fresh. Dont add lots of junk.

Now that said, anyone have comments on this stuff:

http://www.uview.com/ProductDetail.php?PartNumber=480300

auto parts store stop leak junk I wouldnt touch ever, but this stuff seems to be a different chemistry and possibly of use. Any real-world experience or thoughts?

leathermang · #5 02-26-2010, 04:55 PM

It is by far the agreed upon position by those I trust on this forum and in the books... that putting in new seals- properly lubricated, ( if there is a leak ) and then doing those things you mentioned is the way to go...
Why would people think that a leak sealer would not also seal up small areas which are supposed to be OPEN to work ... like the TxValve ?
I have not gone and looked at that url...
but since the basics do work for sure I doubt I would ever try it...no matter what it is or claims. Simple is Better in a lot of cases... particularly in AC where CLEANLINESS is also rewarded.

Ok , just went and looked... not a chance I would ever use that or any other dye... only leak detectors can be trusted to find a leak in an evaporator or in tight hard to reach places.. or leaks high in the system where that dye will not be close to the actual leaking hole.

JHZR2 · #6 02-26-2010, 05:37 PM

The thing with that gunk is that it supposedly stays in solution and only seals when exposed to air... Kind of like an aerobic sealant.

if it truly stays in solution, it may travel around too, at least to a small amount.

I dont trust anything but a mechanical repair, but still, sooner or later technology will likely produce a viable solution... It will have to especially as we go to CO2 systems.

leathermang · #7 02-26-2010, 05:51 PM

If is truly stays in suspension
AND does NOT adversely affect the phase changing ability of the refrigerant being used...
I am with you... since a mechanical fix has been used for decades with perfect results.. I will be taking the conservative route in AC work.

ah-kay · #8 02-26-2010, 05:57 PM

Some members here make a big deal on A/C. A/C is a science but not an exact science. An oz of oil here and there, an oz of freon/R134a over or less is not going to make the A/C go crappy. It may not be as 'efficient' as one would like it to be but this is the real world. Even if you tune it to be exact, which is next to impossible, it will be out by next month due to minute leak or dirt on evap fins etc.

If everything on a car has to be engineered to be within mircon, milligram, millilitre tolerance then car will be prohibitively expensive. My $0.02.

vwnate1 · #9 02-26-2010, 06:13 PM

The best AC guy in my shop (I work in a HUGE heavy Duty Truck Shop) replaced the compressor on his own car and because he was in a hurry , he trusted the vendor who sold him the new compressor (Delco R4 natch) that it has been shipped dry so he flushed the system and added the correct amount of oil then charged it , it blows cool but not cold .

Looking underneath the packing materiel in the box he found a tag saying " do
NOT add oil !! this compressor comes pre - filled with the correct amount of oil and adding more will blah ,blah blah..."

So , it's cool but not cold , yes a couple ounces of refrigerator oil will indeed screw things up for you .

it won't break but it will not cool properly either .

Yes , I'm a Jounrneyman Mechanic but no , I'm not an AC tech , I just have to work on the damned things occasionally so I pay close attention to what the HVAC guys tell me and I avoid < magic> fixes like leak stop etc. like the plauge .

ah-kay · #10 02-26-2010, 06:22 PM

Quote:

Originally Posted by vwnate1

Looking underneath the packing materiel in the box he found a tag saying " do
NOT add oil !! this compressor comes pre - filled with the correct amount of oil and adding more will blah ,blah blah..."

So , it's cool but not cold , yes a couple ounces of refrigerator oil will indeed screw things up for you .

2 issues here:

1) He should have read the instructions. Most new compressors come with pre-filled now and it is R134a compatible oil.
2) Prefill is not 1 or 2 oz. It is about 8 oz. That means he was 8 oz out ( approx 100% ) even he measured the EXACT amount he thought he needed to put in. It still works, it goes to show the tolerance of the A/C system.

BTW: I do not know how to define cool or cold, it is subjective.

leathermang · #11 02-26-2010, 07:48 PM

Quote:

Originally Posted by ah-kay

2 issues here: 1) He should have read the instructions. Most new compressors come with pre-filled now and it is R134a compatible oil.

OK, maybe we have found one of the causes of your off the wall attitudes towards many accepted AC procedures..

The Delco R4 HAS NO SUMP... THUS CAN NOT BE PRE FILLED.

That piece of paper was put into all the compressors that company shipped.

The AC system initial oil charge is put spread around the system .. not into an R4 Delco compressor.

If a normal swashplate type, for instance, is used.... it has both a sump into which oil is placed.... and would typically come from the factory that way... then the correct amount would be spread around the system for top end lubrication.

ah-kay · #12 02-26-2010, 08:25 PM

It is so stuffy here that I need to get out of the room.

Matt L · #13 02-26-2010, 08:34 PM

I would never trust a prefilled compressor. How do you know that they put the "correct amount" in the new compressor when they have absolutely no way to determine how much oil was left in the old one? Answer is, of course, they cannot and do not.

Is there a crankcase drain on the R4? I would bet that this is what they mean by sump.

TOPGUN · #14 02-26-2010, 11:28 PM

There are members within this post that obviously know exactly what they are talking about. I hope the less experienced members can see through the crap that might get somebody injured in a big way. The stop leak and oil checker things bring to mind the "the fool and his money will soon be parted". As far the the high mileage r134, I am still laughing. What if you have a new compressor in an old car? Still high mileage? Taking a dangerous short cut is foolish. I have 35 years in the HVAC service industry with a well known fortune 100 company and still read very carefully any AC posts submitted by 2 of the safety first guys within this post. Thanks for reading my rant.

vwnate1 · #15 02-27-2010, 12:07 AM

A rant IMO .

Safety knows no season ! .

I thought the swashplate typ of compressor was the R-6 , no ? . I've never taken the R-4's apart but we used to make little " Aliens " out of read R-6 guts..

NO ONE who actually lives in San Diego can't tell the difference between cool and cold