AC Hose Problems 190E 2.3 - Need Advice - PeachParts Mercedes-Benz Forum

darius · #1 05-20-2002, 04:33 PM

So, I went to the AC shop this morning, hoping for a quick recharge of R-12 to get me on the road again. Turns out the suction hose (low end side), the one that is covered in foam shielding, has literally blown a hole in it. The hole is on the underside, and I havent had time to cut off the shielding, get a mirror and look. So, a new hose (even from Parts Shop) is $375. This shop would order one for me, install it, dry out the system, and recharge for oh, not more than $1300. $1300!!!
So, here is my question: The mechanic I spoke with this morning also advised trying to put a splice in the hose...after we cut away the foam rubber...and then trying to get a charge on the system. Don't forget...the system has still yet to take a charge, and thus I dont know the status of the compressor.
Do I try the splice? If it works...total charge, including drying of the system and recharge is gonna be $500. If it doesnt work...I am out $65 in labor for the splice...and I know that I have a trashed compressor.
I am going to be replacing this car in 15 months...but man, is it gonna be a hot summer.

Also, do I need to have them dry the system? I know it has gotten tons of moisture...but must this be done before I even find out if the compressor is good? or is that just something they will do if they determine the compressor is good...and are getting ready to re-lube and re-charge the whole system.

Any advice?

- Thanks in advance,

John
Richmond, Va.
'85 190E 2.3L 128k miles.
'83 300D Turbo 308k miles.

tcane · #2 05-21-2002, 12:44 AM

If the hole is in the rubber hose section of the AC line, then replace the rubber hose. Many AC parts suppliers rebuild AC hoses for home and commercial applications. I had both of my AC hoses rebuilt by replacing the rubber hose section to the metal ends - works great and cost about $40 to have both hoses rebuilt. Make some phone calls to find a place that will rebuild your hose. Then look to see what caused the hose to fail in the first place and do what is needed to make sure the new AC line is not damaged again.

For the price you're being quoted, you could instead go to Sears and buy a tool assortment w/ toolbox, R&R the AC line yourself & have it rebuilt, and then take the car to have a vacuum drawn and charge the system with freon & oil. On eBay, freon R-12 is selling for $15-$20 per pound (a price range I've seen for R-12 not sold on eBay) and a reasonable mark-up would be $30-$35. Say they really put it to you on the R-12 and charge you $60 per pound, your system probably needs 3-4 pounds for total cost of freon of $180-$240, add a bit of oil for say $10-$15, and then the time to draw a vacuum and charge the system with freon & oil - about 1 to 1 1/2 hour at say a labor rate of $60 per hour - for a total of $255-$345. Repair cost of the old line at an AC supplier for about $20-$40. For the $500 you were quoted to have the AC line spliced, you would have about $100-$125 to buy a nice tool assortment from Sears and have an AC line that is completely reliable instead of spliced.

As to the compressor - try turning the compressor by hand. Feel how easily it turns, feel for roughness, and listen for odd sounds. If the compressor turns without binding and no odd noises, then it is probably OK. But, you really won't know until the AC line is repaired, freon/oil added, and then try running the compressor. The system is initially charged with freon and oil until there is enough freon pressure to trigger the compressor clutch to engage so the compressor begins to rotate - then the system is fully charged with freon while the compressor is rotating (obviously, the engine is running) using pressure gauges to monitor the pressure in the low and high sides of the AC system and adding freon until the pressure readings are in the proper range. Unless, your 190 calls for using what's called a "charging cylinder," which means that a specified amount of frreon is put into the charging cylinder (this amount is the full amount of freon your system is supposed to hold, so many pounds and ounces), oil is first added, and then the charging cylinder is connected to the low side AC line and the freon is added to your AC system until all the freon in the charging cylinder is gone. How long since the last time the compressor and AC system worked? If it worked OK before the loss of freon, then there is a reasonable chance the compressor will work after fixing the AC line.

A vacuum of 27 + inches of mercury should be drawn for 30 minutes to remove the moisture. Moisture will freeze and inhibit the proper functioning of the AC system. Also, drawing a vacuum will help remove crud if any has entered the AC system.

Good Luck!
Tom

BobK · #3 05-21-2002, 07:16 AM

Look in the yellow pages for a shop that builds/rebuilds hydraulic hoses. I've had several done that way. You just take in the old line with fittings still attached and they put new a/c hose on the fittings. Cheap and usually fast. (while you wait sometimes!) Buy a bunch of the new o-rings that work on R12 and R134A. Take some of the old ones with you for size. While you are in there, is it time to convert to R134A? PIA, but a whole lot cheaper and more available than R12. BTW, if that system has been open for any time at all, you might want to replace the receiver/dryer. I'm about to replace the compressor on my wife's '86 190E so I feel your pain. Price for used compressor and local yard is $250 +core. New rec./dry. and TXV will be another $100+. I'll be doing the work myself so I save a lot, but still a bunch of $$$$. However, the cost of a wife sitting in traffic on a hot day with no a/c is beyond measure.

J.HIDALGO · #4 05-21-2002, 09:55 AM

check with Aeroquip? I have not tried that yet but, I read that they can put fittings in the portion where the hose attaches to the metal so, the next time you have a leaky hose all you have to do is replace (unscrew/screw) just the rubber hose. Price is suppose to be similar to just replacing the rubber hose. They should be in the phone book.
As stated before, you may also want to convert to r134. This is the perfect time to do it.
Let us know what happens!