Howdy, I have seen a whole lot of threads debating refrigerant, many reading: [something to the extent of] "if correct procedure [for conversion] is followed...".

What is the correct procedure for converting over to R-134?

Any links to websites or threads covering it step by step?




Please do not argue over which refrigerant is better folks.

Thanks,
John

__________________
1986 190D, 2.5L, 5-speed swap, 180,000 Miles (60K by me).
Jeep CJ-7 with Cummins 4BT/NV4500/AtlastII 4.3.
Grand Wagoneer 4BT project in progress!

*Evac system, although it probably already is.
*Flush entire system {except compressor} and change all the orings. The lines need to come apart anyway for the flushing. Buy some Nylog to seal the orings. I've used it on 2 cars so far, and no leaks. It's cheap, too.
*Replace rec/dryer, expansion valve. Be sure and get a new pressure switch that monitors Low AND High pressure.
*Some folks say to replace compressor also since you can't flush it.
*Install the correct R-134A fittings to High and Low sides.
*Add the correct amount of Pag oil (or similar R-134A oil)
*Install gauges.
*Vac system down for 1/2 hour to an hour and make sure it holds around 29 units of vac. for several hours.
*Some folks also like to pressure test with nitrogen. A can of R-134A would do about the same.
*If this holds, add the appropriate amount of R-134A.

I hope it doesn't get over 95 degrees where you are. If not, that will be OK. Hotter than that and your vent temps won't make it to the 40's.

If you find and install a parallel flow condenser, R-134A will work much better.
Others will chime in with better info, but that is my effort.
Good luck!
No sermon......... {although I have both and R-12 is so much better when very hot!}


Nylog = http://www.ackits.com/merchant.mvc?Screen=PROD&Store_Code=01&Product_Code=RT200R&Category_Code=

good info on that site, also.

__________________
Jimmy L.
'05 Acura TL 6MT
2001 ML430 My Spare

Gone:
'95 E300 188K "Batmobile" Texas Unfriendly Black
'85 300TD 235K "The Wagon" Texas Friendly White
'80 240D 154K "China" Scar engine installed
'81 300TD 240K "Smash"
'80 240D 230K "The Squash"
'81 240D 293K"Scar" Rear ended harder than Elton John

Jimmy, thanks for the info. I am quite mechanically inclined, but have never messed with A/C so some things need to be clarified.

No problem.

What is used to flush the system? How would I go about this?

I see R-134 retro kits on ebay, do you suggest these?
http://cgi.ebay.com/ebaymotors/Mercedes-Benz-190D-190E-230-240D-280-280C-R134-Retrofit_W0QQcmdZViewItemQQcategoryZ33544QQihZ001QQitemZ110121757435QQrdZ1QQsspagenameZWDVW


Where do you suggest I find such a switch?

May as well give the thing a try.

E-bay kit above has them.

Do I go by capacities listed on the under hood stickers?

Will these do the job?
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=92649

$10, any good?
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=92475

Throwing a can in and going from there sounds like a good idea.

Again, same amount that underhood sticker indicates?


Na, not many days are 90*

Thanks,
John

__________________
1986 190D, 2.5L, 5-speed swap, 180,000 Miles (60K by me).
Jeep CJ-7 with Cummins 4BT/NV4500/AtlastII 4.3.
Grand Wagoneer 4BT project in progress!

Might be a dumb question, but why change from R-12?

__________________

Gone to the dark side

- Jeff

There's no argument.

Jimmy, thanks for the info. I am quite mechanically inclined, but have never messed with A/C so some things need to be clarified.

Quote:
Originally Posted by JimmyL
*Evac system, although it probably already is.
No problem.

Quote:
Originally Posted by JimmyL
*Flush entire system {except compressor} and change all the orings. The lines need to come apart anyway for the flushing. Buy some Nylog to seal the orings. I've used it on 2 cars so far, and no leaks. It's cheap, too.
What is used to flush the system? How would I go about this?

I used alcohol to flush my system. I had access to a couple of gallons of it, and I like the way it dries out afterward. There are specific flushes for this purpose, but it can get costly to do a thorough flush...

I see R-134 retro kits on ebay, do you suggest these?
http://cgi.ebay.com/ebaymotors/Merce...spagenameZWDVW

That actually looks fine. I got a kit from the place with the Nylog for Euro cars, and also a large one from Autozone.


Quote:
Originally Posted by JimmyL
*Replace rec/dryer, expansion valve. Be sure and get a new pressure switch that monitors Low AND High pressure.
Where do you suggest I find such a switch?

Click the "Buy Parts" tab up top, and you can probably find it there. Most any place should have it.

Quote:
Originally Posted by JimmyL
*Some folks say to replace compressor also since you can't flush it.
May as well give the thing a try.

Columbus took a chance, and look what happened...... Kinda worked out.

Quote:
Originally Posted by JimmyL
*Install the correct R-134A fittings to High and Low sides.
E-bay kit above has them.

yep

Quote:
Originally Posted by JimmyL
*Add the correct amount of Pag oil (or similar R-134A oil)
Do I go by capacities listed on the under hood stickers?

Yes. I used 7oz. Seems like it calls for 6. Some say 8.

Quote:
Originally Posted by JimmyL
*Install gauges.
Will these do the job?
http://www.harborfreight.com/cpi/cta...emnumber=92649

I got 2 different sets of those from Harbor Freight. First set had a bad o-ring, second set was too narrow to fit over the high side fitting.
AND, that vac pump is crap. Use a tool loner program from a local auto parts store (like Autozone or Napa or O'Reilly's) and use their guages and vac pump.

It isn't hard work at all. You will also need new sealing rings at the back of the compressor if it is similar to the kind on a W123. I'm not that familiar with W201's.
Peruse that AC website with the Nylog. Good info. And believe it or not, Autozone has a $6.00 buck DVD that shows an AC flush and rebuild. It is very good info, even if it is on a Chevy PU. I watched it several times for reference.

__________________
Jimmy L.
'05 Acura TL 6MT
2001 ML430 My Spare

Gone:
'95 E300 188K "Batmobile" Texas Unfriendly Black
'85 300TD 235K "The Wagon" Texas Friendly White
'80 240D 154K "China" Scar engine installed
'81 300TD 240K "Smash"
'80 240D 230K "The Squash"
'81 240D 293K"Scar" Rear ended harder than Elton John