Any oil loss during evacuation? 2 questions - PeachParts Mercedes-Benz Forum

ps2cho · #1 06-09-2011, 02:05 PM

I backconverted to R12 on my 260E (it was converted to r134 by PO) when I replaced the evap/exp/accum and it was working great for about 6months then it stopped....

I checked pressures and they were too low, so I got a leak somewhere.

After some thinking, the only seal I did not replace during the R&R was the big rectangular seal at the compressor manifold (just forgot I guess?)
Think thats the place it will be leaking from? I'm gonna charge it, add some UV dye and see if that is the location.

----> IF it IS....I'll need to disconnect and replace seal.

1) I shouldn't need to replace R/D in this scenario if I do it quick right?
2) Since it will be in open air and completely evacuated, do I need to add oil or does evac leave oil in the system?

I'll be using a simple dual stage vac pump.

Thanks guys

engatwork · #2 06-09-2011, 02:10 PM

Did you replace the hoses?

leathermang · #3 06-09-2011, 02:30 PM

Much better to NOT use DYE...
put in R22 with nitrogen and use SNIFFER>..
DYE has potential for causing problems all by itself...
and will not show you a leak in the evaporator for instance....

engatwork · #4 06-09-2011, 02:57 PM

Quote:

and will not show you a leak in the evaporator for instance

Is it just this application or are you making that statement as a general rule? If it is a general rule then I am going to respectifully disagree with you on this one. I had a 04 BMW 325i through here last week that had blown an evaporator. I got underneath it with my trusty UV flashlight and there was dye all down the side of the tranny and some on the transmission tunnel. It was quite evident it was coming from the evap housing.

leathermang · #5 06-09-2011, 03:48 PM

Jim, if you have a blow out and all the dye is lost from the evaporator.. .enough to run out of the drain tube... and you want to get under the car to find that... sure... but civilized people are usually going to be looking at a small leak.... which might be at the top of the evaporator... meaning little or no dye would come out... and a small leak can be sniffed at the vent easily with a sniffer and you dressed in clean clothes.....
And then there is the question of needing to get that dye out to make sure it will not cause problems itself...
The chances that an evaporator leak will be big enough to show up dye out the drain tube is one in 47,936. So I am just playing the odds... and the residual physics too.. ( the contamination avoided by not using dye in the system in the first place )...

engatwork · #6 06-09-2011, 03:59 PM

Quote:

So I am just playing the odds... and the residual physics too..

I gotcha.

In talking with the young lady that was in the car it seems everything was fine and then they hear a hissing sound followed by a unique smell and it was obvious where to look.

leathermang · #7 06-09-2011, 04:11 PM

Quote:

Originally Posted by engatwork

I gotcha.

In talking with the young lady that was in the car it seems everything was fine and then they hear a hissing sound followed by a unique smell and it was obvious where to look.

LOL... you really had that one drop into your lap...
After that description from her.... you put dye in ?

engatwork · #8 06-09-2011, 04:31 PM

No sir, I offered to put dye in but before I did I figured I'd nose around a little with the uv light to see if anything was already there and it was. Somebody had already added dye. I take it cars don't come from the factory with it in them? What does dye do that is detrimental?

leathermang · #9 06-09-2011, 04:35 PM

Has the potential for stopping up the TXvalve....and at some concentration messing with the pflow condensors....
Someone posted just in the last week about having added dye and it stopping the system pretty fast... bummer...
Girl in a BMW... was she pretty ?

engatwork · #10 06-09-2011, 04:40 PM

She is but it was her boyfriends car.

whunter · #11 06-09-2011, 05:59 PM

Quote:

Originally Posted by ps2cho

I backconverted to R12 on my 260E (it was converted to r134 by PO) when I replaced the evap/exp/accum and it was working great for about 6months then it stopped....

I checked pressures and they were too low, so I got a leak somewhere.

After some thinking, the only seal I did not replace during the R&R was the big rectangular seal at the compressor manifold (just forgot I guess?)
Think thats the place it will be leaking from? I'm gonna charge it, add some UV dye and see if that is the location.

----> IF it IS....I'll need to disconnect and replace seal.

1) I shouldn't need to replace R/D in this scenario if I do it quick right?
2) Since it will be in open air and completely evacuated, do I need to add oil or does evac leave oil in the system?

I'll be using a simple dual stage vac pump.

Thanks guys

If the compressor manifold line seal is bad = high risk the compressor oil charge is gone also.

.

ps2cho · #12 06-09-2011, 09:52 PM

Quote:

Originally Posted by whunter

If the compressor manifold line seal is bad = high risk the compressor oil charge is gone also.

.

Makes sense...When I was trying to diagnose, at one point the clutched kicked on, but there was a noticeable horrible noise coming from the compressor so I turned it off immediately. I guess the only safest action is removal of compressor, drain and refill again?

The rest of the system should be good though right? I'd really hate having to pull all hoses and flushing them again. That would be a real PIA.

And to first post, no original hoses. I flushed them with solvent thoroughly during the backconversion.

engatwork · #13 06-10-2011, 07:30 AM

ps2cho I would not rule out leaking hoses if they are the original hoses that came on the car.

ps2cho · #14 06-11-2011, 08:33 PM

Quote:

Originally Posted by engatwork

ps2cho I would not rule out leaking hoses if they are the original hoses that came on the car.

Not sure....I know that the dealership converted the original system from R12 to R134a, so I'm not sure if they were replaced or not....That's all I know.

Would it leak at the crimped points?

engatwork · #15 06-11-2011, 08:51 PM

That is where I have seen leakage from before.

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