A/C recommendations for the MB vehicles - Page 14 - PeachParts Mercedes-Benz Forum

dieseldan44 · #**196** 10-17-2011, 03:12 PM

Quote:

Originally Posted by leathermang

Now tell us how this thought came to you ....Do you think it is going to be that hard changing it over to the proper fittings ?

vstech mentions earlier that the fittings are usually brazed on, or red loctite'd on...so when you try to remove the 134A fitting, it rips the valve nipple off the hose. Resulting in a $75 purchase for the upper hose, $250 for the lower hose (on a W123 as of this writing).

Thats how the thought came to me...as Im sure it had occurred to others.

dieseldan44 · #**197** 10-17-2011, 03:22 PM

Question: Do I need to put oil in a brand new AC compressor *before* I put it on the car? Or can I put the oil in later once it's installed?

leathermang · #**198** 10-17-2011, 03:54 PM

What did your new compressor instruction say to do ?
Or , what did Tray suggest ?
Did you get some of the Castrol cold flow 500 yet ?
You are doing a thorough job on all the rest...
don't half way some of these other things..

since you will have the system apart...
consider installing a schroeder fitting near the other one...

leathermang · #**199** 10-17-2011, 03:55 PM

Your compressor may have ' break in ' oil in it...
need to read the directions closely...

Remember, the first four minutes ( AT THE very LEAST ) of the compressor running need to be at idle speed....

ROLLGUY · #**200** 10-17-2011, 09:39 PM

Quote:

Originally Posted by leathermang

It is a bad idea because you could screw up someone's recovery machine by it not being identified correctly...... sorta of the Golden Rule....

Most (if not all) good A/C shops have a refrigerant analyzer and use it before recovering any refrigerant into their machine. I doubt recovering R12 into a 134 machine (or the other way around)will damage the machine, but it's the container of refrigerant that will get contaminated. A certain percentage of R134 in an R12 container will render it useless, and that would be a costly mistake. The technician I use always uses the analyzer even with the slightest doubt of a possible mixture of the two (it also detects "designer" refrigerants).

dieseldan44 · #**201** 10-18-2011, 12:43 AM

Quote:

Originally Posted by leathermang

since you will have the system apart...
consider installing a schroeder fitting near the other one...

what do you mean?

ps i need to give tray a call. and btw, this castrol cold flow 500 doesn't seem to exist :-) perhaps its under a different brand? i ask tray when i talk to him and post.

leathermang · #**202** 10-18-2011, 12:57 AM

Rollguy.. I was really thinking about some of our forum members who might trust the fixtures on something like this when working on a car bought from another forum member... certainly pros should be checking to guard their assets...
I was using ' recovery machine ' in the broadest sense.... as in a chilled container used to store refrigerant which might be put back in by one of our DIY guys.... perfectly legit, cheap, but dangerous in the context we are discussing....

Dieseldan,
What kind of line is the old valve on ? Rubber or metal ?
I mean install a new one instead of taking a chance on messing up the line .....

ROLLGUY · #**203** 10-18-2011, 01:33 AM

If you can't get the 134A service fittings off without ruining the line, there are plenty of good used one's available. If I were in your shoes, I would be replacing the rubber hose portion anyway. Many A/C shops can replace the hose and use your old hard lines. Or you could find a good used set, and just leave the 134 fittings on them and sell (or trade/give) them to someone that has an unmolested R12 set (that may want to convert to 134A).

leathermang · #**204** 10-18-2011, 11:14 AM

I think he should replace the rubber too... as he is replacing almost everything else.... he will be in high clover when he gets done if he follows the rules...

Here is an interesting pdf ..... which shows Castrol 525 cold flow..which may be old or not available..

I am really posting it for all the other good info in it...

www.meicorporation.com/pdfs/Tools09.pdf

dieseldan44 · #**205** 10-18-2011, 10:38 PM

Quote:

Originally Posted by ROLLGUY

I] Many A/C shops can replace the hose and use your old hard lines.

hmmm, any ideas on what type of shop would make these? would a general HVAC shop be able to do this?

we don't have AC shops for cars up here like Carlisle that I can find :-/

dieseldan44 · #**206** 10-19-2011, 07:56 AM

sorry leathernamg...did not mean to dodge the question...

Quote:

Originally Posted by leathermang

Dieseldan,
What kind of line is the old valve on ? Rubber or metal ?
I mean install a new one instead of taking a chance on messing up the line .....

the valves are on the metal portion of the hose on both top and bottom.

I took the top hose R134 fitting off fine.

the bottom one also came off easily - I heated it right up with a propane torch and it came out with no damage to the valve (that i can see now).

however, as you have mentioned the hose itself is a little suspect - i can spin it at one of the rubber to metal points.

ROLLGUY · #**207** 10-19-2011, 10:20 AM

Quote:

Originally Posted by dieseldan44

hmmm, any ideas on what type of shop would make these? would a general HVAC shop be able to do this?

we don't have AC shops for cars up here like Carlisle that I can find :-/

I say "many" (being in So. Cal.) around here. Both shops that I have worked with over the years have all the tools and supplies to replace the rubber hose section only. I am sure other shops do it as well.

ROLLGUY · #**208** 10-19-2011, 10:32 AM

Quote:

Originally Posted by dieseldan44

i can spin it at one of the rubber to metal points.

That should not be an issue.
Even after replacing the rubber hose (and new sleeves), the hose is able to be turned on the metal tube.

leathermang · #**209** 10-19-2011, 12:20 PM

DieselDan44, Can you take pics of these ? When you heated it are you saying you desoldered it and it came off ?
Are these off the car and already flushed well ? Otherwise heating might cause corrosion on the inside... or baked on carbon... A shop working on this type of stuff would partially close off one end and put Nitrogen to the other end.... to prevent oxidation....just as one would TIG it ....Have you found that R12 Schroeder valves are available to Silver solder on where you took the other off ?

vstech · #**210** 10-19-2011, 05:00 PM

I believe he heated the adapters slightly to loosen any loctite from the fittings, and unscrewed the adapters. I doubt he actually removed the fittings from the lines!