Leaks at Filter/drier--Dodge B350 Van

[jluke42]

I am working on one of our church's vans. It is a 1994 Dodge B-350 5.9l with dual a/c. The vehicle developed a leak in the front evaporator. I replaced the evaporator. While I had the system open and since I had the entire gasket/oring set, I decided to replace all the gaskets and orings in the area around the evaporator and valve. Bad idea! When I could not hold a vacuum after reassembly, I took my tank and introduced some refrigerant into the system. Using soapy water, my only leaks were at the metal gaskets on both sides of the filter/drier. My first thought was that I did not clean the sealing surfaces well. I disassembled and used a Scotchbrite pad to clean all sealing surfaces. I was meticulous in the cleaning and reassembly with new gaskets. Try again--same thing, leaks on both sides of the filter/drier at the metal gaskets.

To all who are familiar with Chrysler systems of this vintage, the nuts that hold the flanges to the drier are offset and apply force to the sealing areas in kind of a cantilever fashion. The metal gaskets have raised circles around the sealing area which I assume are supposed to compress and complete the seal. Is my thinking correct? The drier appears to be the original one. The church purchased the vehicle new and to my knowledge the only other work done to the system was a compressor replacement due to a leaking shaft seal a few years back. Other than that, the system has performed well all these years.

My questions are, " What am I doing wrong?" and "Is there some type of sealant I should be using?" I intend to replace the drier thinking maybe the studs which the attaching nuts screw onto may be distorted. I do not see how the flanges on the lines could be distorted since they are about 7/16 " steel.


Thank you in advance for your help with this problem. It is about to drive "bonkers". Thanks again.

[bohica2xo]

There should be a counterbore on either side of the dryer.

There should be a corresponding nipple on the fitting that mates with the dryer. There is an O ring for the nipple.

[Dougflas]

You should be replacing the dryer also. Use Nylog on all sealing surfaces.