preparing for 100% AC replacement on the coupe - PeachParts Mercedes-Benz Forum

lutzTD · #1 04-21-2011, 10:49 AM

well I bit the bullet and bought all new components for the coupe's AC. Once I get the motor squared away I am going to rip it all apart again and replace 100% of the components. I have all new hoses, condenser coil, evap coil, expansion valve, dryer and 15lbs virgin R12. Is there a step by step I can follow to make sure I get this all correct? Orings oil etc? I have a charge scale and a set of guages to do the install, one of my neighbors is a general AC guy and is going to help. I guess where Im lacking is in the leak check dept. thanx for any help. I plan to do this in about a month.

leathermang · #2 04-21-2011, 11:17 AM

You need a really accurate scale...
Keep all those items wrapped in plastic bags... the ends... sealed with rubber bands...
You want NYLOG of the proper COLOR for R12.
I do not know if there is a ' step by step ' per se..
but all the info is in the Archives..perhaps use my name in the advance search... I may not have said ' it ' .. what you need to know... but you can figure I showed up somewhere in the thread... thus use ' threads' and my name will cut down on the number of threads to read... LOL... but not by much....
AND our AC contractor Moderator Vstech is in the process of doing something close if not exactly in the sticky at the top of the page..

lutzTD · #3 04-21-2011, 11:48 AM

Quote:

Originally Posted by leathermang

You need a really accurate scale...
Keep all those items wrapped in plastic bags... the ends... sealed with rubber bands...
You want NYLOG of the proper COLOR for R12.
I do not know if there is a ' step by step ' per se..
but all the info is in the Archives..perhaps use my name in the advance search... I may not have said ' it ' .. what you need to know... but you can figure I showed up somewhere in the thread... thus use ' threads' and my name will cut down on the number of threads to read... LOL... but not by much....
AND our AC contractor Moderator Vstech is in the process of doing something close if not exactly in the sticky at the top of the page..

awesome thanx, Maybe ill try to take pictures of each step then someone can fill in the blanks with the correct procedure for each.

Vstech, you are cordially invited to do the whole job and write it up, I will supply the parts and the beers.

leathermang · #4 04-21-2011, 01:03 PM

LOL... are you close enough to get it to Vstech ?
That would be awesome......
and really fortunate for you...
Yes, you really need to take lots of pictures and share them.. consider adding light instead of depending on just the built in flash... can make a huge difference in quality of the pics.. and know your camera with regards to ' close up ' distance focusing... and the extra lights can help your camera focus ....
never know when someone will need a particular angle view to help them with their situation..

vstech · #5 04-21-2011, 02:41 PM

Quote:

Originally Posted by lutzTD

awesome thanx, Maybe ill try to take pictures of each step then someone can fill in the blanks with the correct procedure for each.

Vstech, you are cordially invited to do the whole job and write it up, I will supply the parts and the beers.

It's a bit of a drive ... & I don't drink hardly ever but I'm facing the same retrofit on my SD & TD so I'll take pics also & we can both contribute to a DIY!

lutzTD · #6 04-21-2011, 02:44 PM

OK, hey Im seeing a lot of cheap leak detectors on the bay, any that I should look for avaoid? some are as cheap as $40 for a sniffer type

Quirky Mercy · #7 04-21-2011, 10:40 PM

I have had good luck with a good leak detector soap. It is cheap and works well. I would not buy a cheap electronic detector from past experience. I like to purge/pressure check with nitrogen, soap the joints then pump it down to 500 microns or less let it set and if it holds you are good. Like Leathermang stated keep everything clean, surgical clean. Looking forward to the write-up.

leathermang · #8 04-21-2011, 11:01 PM

Quote:

Originally Posted by Quirky Mercy

I have had good luck with a good leak detector soap. It is cheap and works well. I would not buy a cheap electronic detector from past experience. I like to purge/pressure check with nitrogen, soap the joints then pump it down to 500 microns or less let it set and if it holds you are good. Like Leathermang stated keep everything clean, surgical clean. Looking forward to the write-up.

The problem with soap is that it will not help find a leak in the evaporator... the primary leak I had on my 81 wagon....
Which electronic detector brands are trustworthy ?

vstech · #9 04-22-2011, 12:10 AM

... I have no idea what brand my detector is. I got it at my refrigeration supply house...
it's not an ideal, or a ritchie... they were too expensive. it's universal refrigerant sensitive, and it works... something like 150.00 (I charged it to a customer, and put it on my account, so I have no idea what it actually cost...) *(I'm not a great business man...)

it's HIGHLY unlikely any mobile refrigeration system could EVER achieve 500 microns, and it's even less likely to remain there if it did reach it.
below 2000 microns is difficult, below 1000 would be holy grail of tight systems.
HERMETIC systems can reach sub 400, and I shoot for 200 on my R410 installs, and I watch like a hawk the meter, for a raise before I charge them....
but semi herms like automotive, are near impossible to reach below 1000 due to the hose porosity, the seals, the compressor crankshaft, etc...

leathermang · #10 04-22-2011, 01:00 AM

Seems like this is something we need in the rental/loaner program..
I'll put up $20 towards that .... anyone else ? John, can you check on what one would cost using your connections ? Whichever one you trust and consider the ' sweet spot ' for price and abilities....

vstech · #11 04-22-2011, 10:25 AM

the biggest problem with the detectors is the learning curve with use, and the fragile nature of them.
mine has replaceable sensor elements, that need cleaning, and installation/removal upon storage...
they are fragile and expensive... not really a good choice for rental i'd think.
the ultrasonic style are pretty robust, but their use is limited in a vehicle style use, due to hidden components and such...

leathermang · #12 04-22-2011, 11:28 AM

Well, with a high enough deposit ...and someone with expertise to check it when it returns... it might work.. but it is hard to circumvent 'Stupid'.... LOL

lutzTD · #13 04-22-2011, 11:42 AM

Im hoping my neighbors buddy has one, hes pretty sharp and I can easily imagine him to be a tool collector. He did install home ac's earler in his life so Im thinking it might already be taken care of for me.

Matt L · #14 04-22-2011, 11:50 AM

Quote:

Originally Posted by leathermang

Well, with a high enough deposit ...and someone with expertise to check it when it returns... it might work.. but it is hard to circumvent 'Stupid'.... LOL

Pretty unlikely. All it takes is to put the probe into some oil, and the tip is gone. The tip isn't replaceable on the cheapest of the units, so that's the whole thing.

You can ask for a high enough deposit, but then you'll have some hurt feelings (or worse) when someone returns it, says that it's still good, and you think it's toast.

leathermang · #15 04-22-2011, 12:09 PM

Matt , I suspect that you are correct on each and every point you made...
Practical junk gets in the way of cool ( pun ) desires... LOL
I already own one from Ebay... but have not had a leak to check it on ...
It arrived with battery acid having leaked from the batteries ( where else would it come from ? ) I cleaned it and think it will work... have been praying for a leak....
(Not really... LOL )