A common problem with the climate control (PBU) is that the solder joints crack and need to be re-flowed. It is easy to do. Just remove the PBU and take the cover off. Then just put your soldering iron tip on each solder joint, thereby re-melting the solder. This should restore the unit to it's proper function....Rich

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All Diesel Fleet
1985 R107 300SLD TURBODIESEL
2005 E320 CDI (daily)

LOTS of parts for sale!


EGR block kit
http://www.peachparts.com/shopforum/diesel-discussion/355250-sale-egr-delete-block-off-plate-kit.html

1985 CA emissions 617 owners- You Need This!
Sanden style A/C Compressor Mounting Kit for your 616/ 617 For Sale + Install Inst.

Sanden Instalation Guide (post 11):
http://www.peachparts.com/shopforum/diesel-discussion/367883-sanden-retrofit-installation-guide.html

No license needed to buy Enviro-safe or the oil. Same deal for Duracool (in all my cars). I think PAO 68 oil is the best one today (any refrigerant) and ideal for our non-sump R4 compressors. See Duracool's site. The fittings for both should be standard R-134A type. If changing from R-12, you will need to install adapters. I vaguely recall that my 300D's had the same-size R-12 port on both low & high sides.

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1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans

I've been getting a short hissing sound from under the driver's side kick plate recently when turning on the AC, so I figured that I should check the expansion valve. Sure enough, there was oil on the plastic kick plate and a little bit of oil on the valve. It's a cheap part, but looks difficult to replace. I was able to get a 17mm tubing wrench on only one of the fittings due to the tight space between the lines. Are there special wrenches that need to be used. Are the lines to the expansion valve just as likely to leak?

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'81 300SD

Those fittings are SAE, not metric - I think one is 7/8 and the othe 11/16 but my memory could be off. I've had good results with crow's foot wrenches and also by using a cutoff wheel to make a very short-handled wrench. If these fittings have never been apart they can really be stuck and you can do serious damage to the copper pipe going into the evaporator. Use MAP gas torch (like a yellow butane torch) to apply heat (have a fire extinguisher handy too) and also use striking blows with a hammer on your wrench, rather than steady torque, to break the fittings loose. Steady torque will twist your pipes rather than breaking loose the fittings

i wired my aux fan into the cabin with a switch that i can manually control. i usually just turn it on whenever i have the a/c on unless i'm on the freeway. its very easy to do and was maybe $10 in parts.

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1981 NA 300D 310k miles

Start up squeal usually is caused by the belt, not lack of oil. Check the belt, it may be shiny...the front shaft seal leaks oil/R-12 mix, gets picked up by the belt and flung off (that's the source of the greasy stripe on the engine side of the hood). In the process the belt gets shined up and squeals...same thing used to happen to power steering pump belts. If the AC shaft leak is bad enough, the compressor clutch gets saturated, and slips/squeals on start up. (brake cleaner sometimes helps cleaning the clutch). Good luck w/the indie. Old AC systems are a heart breaker.

"You just convinced me to take this job to my indie"

- Sorry, I didn't mean to discourage you! Using map-gas heat, combined with sharp, striking blows (not heavy bows, mind you, but use a big hammer) is not so difficult to do and can be useful in other areas too, to break loose stuck bolts (door strike hex bolts, motor mount lower hex bolts). Give it a go, it's not so bad once you try!

Removing the expansion valve only took about 20 minutes and required no excessive force. The tube fitting on the 17mm port required a lot of cleaning and was probably the source of the leak. Threading the bottom 22mm fitting back in has been one of the most frustrating jobs I've done on this car. Today I'm going to remove the grommet at the firewall and hope that that helps me get the angle I need to get that bolt started.

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'81 300SD

I finally got that expansion valve installed. I'm now in the process of replacing every seal that I can get access to. In order to replace the seals on the two lines that feed into the back of the compressor, is it just a matter of removing that backing plate? Will removing those two lines adequately drain the compressor of it's oil, or is there a separate drain plug?

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'81 300SD

I removed those tubes at the expansion valve in my 1985 300D a few months ago, using regular wrenches (big open-ended HF & thin adjustable wrench). I removed the expansion valve too. The task was to replace the bigger suction hose since it was leaking thru the rubber, but I changed all O-rings at the same time. I have a recent thread on how I replaced the hoses. I didn't replace the small "liquid" tubes since they looked fine and rarely fail.

I am about to do the same on my 1984 300D. I started on the broken oil pump tensioner, but those hoses were in my way and looked ready to fail, so figured "why not now" and also eliminate that cumbersome tube run behind the alternator.

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1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans

I've made an appointment for next week to get the R12 evacuated from my system so that I can get started on this project. I found this good tutorial for replacing the W126 expansion valve: Removal and Replacement of Expansion Valve

One of the final steps is to lubricate the o-rings with the same oil used in the compressor and drier. Which oil should I use? All of the PAG oil that I've seen on line is for r134. I need something that comes in a bottle. I'll be replacing the drier too, how much oil goes in there? Thanks

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'81 300SD

Now that I've had my AC system evacuated, I'm ready to start replacing parts. I've ordered an o-ring kit and plan on replacing as many of those as possible. Once I have everything installed I plan on adding 2 oz. of PAO68 to the drier and 5 oz. of PAO68 to the compressor. I've been told that I should rotate the compressor by hand after adding the oil to prevent hydro-lock. How can I engage the clutch on the compressor in order to do this effectively?

Once I've oiled up the compressor, can I start the car and add R12 through the low side port like I normally would when charging the AC, or should I take it to a shop? Thanks

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'81 300SD

Just turn the center of the clutch by hand. If you did power up the clutch, it would be engaged against the drive belt and you would not be able to turn it.

Okay, I thought that you would loosen the belt, engage the clutch and then spin the pulley by hand. I don't know much about AC systems. Is the clutch suspended in the center of the pulley when not activated, and then magnetically attached to the pulley when engaged?

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'81 300SD

Yes, the face of the clutch is pulled towards the pulley making contact and driving the compressor.

As for recharge, the R12 cans don't seal very well once punctured so I'd tend to use full cans only then have it topped off at the shop. R132 cans have a screw on top making them less leak prone.