1997 E420. I had an a/c problem about a month ago. The common low on freon situation. After adding about 1lb of freon it has worked fine since, until the other day. (I knew that only time would tell and that there was a slow leak in the system.) I started to notice the hiss again and knew that soon the temp would rise out of the driver side vents. I have added another can of freon and its cold again.

I noticed that there is a small cannister mounted low right behind the left front headlight. It does have a/c lines running into and out of it along with some kind of pressure switch. That cannister had an oily film on it. I used brake clean and removed the oil film. It has now been a few days and the oil film has returned........

My question is what is that cannister called? It looks like an easy fix as it is right out in the open for the most part. My guess is that is the source of my freon leak...........

Your help is appreciated.

Jeff

 

What no one replied? Its got to be the dryer or receiver or something like that. Just need to get the exact item name so I can start looking for one...........

Again, thanks in advance.

Jeff

 

The fittings are sealed with O-rings, a likely source of leaks. Clean it again and watch it closely to find exactly where it leaks.

If your system has lost a significant amount of oil it needs to be replaced.

On mine the receiver-drier outlet exits forward under a boxed sheet-metal frame rail and I won't be making any happy faces if I need to get to it.

Cheers

 

Craig, the lines into and out of this cannister have o-rings. If I replace them along with the pressure switch that might stop the leak? OK. I'll look at that situation and report back.........

What is the purpose of this cannister do you know?

Thanks, Jeff

 

The receiver-drier contains a desiccant to trap any moisture that might get in the system when it was charged. Evaporators have zero tolerance for moisture as it would freeze in the evaporator causing a blockage, and with the compressor pumping against a blockage.. well you know.

I still recommend you find the exact source of the leak especially since there's a good chance you'll find it. A shotgun approach here could be pricey and ineffective.

The real goal is an AC repair with minimal threat to related components.

Cheers

 

I think before I start diggin in I might add some of the dye. My friend can do that for me. Then I'll clean that cannister again and check to see if the dye is present after............

I guess replacing the o-rings would be the cheapest and quickest repair for my problem, hopefully!

Thanks for your help Craig!

Jeff