A/C problems, help needed. - Page 2 - PeachParts Mercedes-Benz Forum

BSharp · #16 07-30-2011, 01:51 PM

I checked the evap, the fins are clean. I pulled the cond to flush it. It seems it does not flow like it should. If I blow through it there seems to be a slight restriction. It does flow. Should it be very free flowing?

leathermang · #17 07-30-2011, 03:09 PM

I have no way to calibrate what it should feel like with regards to blowing through it...
Perhaps you could find another to compare it to...
it does have small tubes and lots of turns..... so it will have friction getting anything through there... when refrigerant is in there it does not have to flow fast....the top half normally would have hot vapor and the bottom warm liquid.... but an unnatural obstruction would be bad...

BSharp · #18 07-30-2011, 03:31 PM

It also seems the pressures would be off. They seem ok. I have checked every part again and it all seems ok. I flushed everything again. The new expan valve does say r134a but it seems that is the only one avalible. Of course my uses a 1 year only find and radiator.

BSharp · #19 07-30-2011, 03:38 PM

One more thing, I hosed down the cond and took readings again. There still was only about a 15 F drop across the cond and the vent temp stayed about the same. It keeps coming back to maybe contaminated freon.

Matt L · #20 07-30-2011, 03:49 PM

Contaminated with what, though?

Air or too much oil are the most likely things.

BSharp · #21 07-30-2011, 04:03 PM

Quote:

Originally Posted by Matt L

Contaminated with what, though?

Air or too much oil are the most likely things.

Maybe the flush I used. The 1st stuff I used was really crappy. Realized that it did not evaporate worth a crap. Maybe I left a little in. The new stuff is way better. I only added about 4 oz of oil the 1st time.

leathermang · #22 07-30-2011, 04:05 PM

What exactly did you use as flush ? Both times...

BSharp · #23 07-30-2011, 04:34 PM

The 1st time was this stuff from Oreillys, A/CPro Flush and Clean. It says it evaporates quickly but no. There is no alcohol smell to at all. The 2nd time was stuff I bought from an a/c supply place this am. Strong alcohol smell, worked awesome.

leathermang · #24 07-30-2011, 04:39 PM

So, did you use this flush on the parts when they were disconnected from each other.... ?
What did you push them through with ?
Did you flush until you got clean flush coming out ?
Do you have gauges ?
Do you have large or small containers of refrigerant ?

BSharp · #25 07-30-2011, 05:01 PM

Yes, I disconnected everything from each other. I have a flush bottle. Pour the stuff in the bottle, hook it up to shop air and put the rubber tipped nozzle on the part. I did flush it until it was clean. I am using small R12 cans.I have actual R12 gauges also.

leathermang · #26 07-30-2011, 05:07 PM

Why do you think you might have left some in the system ?
How long did you apply air after the liquid stopped coming out ?
You put NO oil in after the last flush ?
When you Did put oil into the system ... EXACTLY what was it ?
What does it say on the can ?

You flushed the condensor, the lines, the evaporator and manually ran new oil through the compressor ?

You have at least a two stage vacuum pump and used that for how long before putting in the refrigerant ?
If you did put oil in the last time... did you spread it around the system ?
Did you install a new rec-drier AFTER THE LAST OPENING UP ?

leathermang · #27 07-30-2011, 05:14 PM

Quote:

Originally Posted by BSharp

I only added about 4 oz of oil the 1st time.

I do not understand this...
You flushed the system the last time... but put NO oil back in ?

BSharp · #28 07-30-2011, 05:20 PM

Quote:

Originally Posted by leathermang

Why do you think you might have left some in the system ?
How long did you apply air after the liquid stopped coming out ?
You put NO oil in after the last flush ?
When you Did put oil into the system ... EXACTLY what was it ?
What does it say on the can ?

You flushed the condensor, the lines, the evaporator and manually ran new oil through the compressor ?

You have at least a two stage vacuum pump and used that for how long before putting in the refrigerant ?
If you did put oil in the last time... did you spread it around the system ?
Did you install a new rec-drier AFTER THE LAST OPENING UP ?

I was thinking some flush MAY have been let in the evap. Since there are multiple routes for the freon to go maybe a little got left behind. I am grasping at straws here. I put FJC Ester oil in after the last flush. Maybe two oz in the comp, one in the cond and one in the evap. I turned the comp over by hand. I have a Robinair Vacumaster pump. I let it run for about 30 mins. I probably should have gone longer. And a new drier every time.

BSharp · #29 07-30-2011, 05:22 PM

Quote:

Originally Posted by leathermang

I do not understand this...
You flushed the system the last time... but put NO oil back in ?

I have put oil back in after each flush. Except today, I am thinking about going to the wrecking yard and comparing back pressure on a cond compared to mine. Yuk

leathermang · #30 07-30-2011, 05:29 PM

Elaborate on the ' multiple routes for the freon to go '.... in the evap cleaning...

Did you not convert the old TXvalve into a ' TOOL' as the FSM suggests for the purpose of flushing the evaporator ?