94 e320 wagon AC leak?
 

My 94 e320 wagon has a refrigerant leak. Injected dye, searched with the UV light.....Nothing conclusive except some specks around the bottom left side of condensor....Any one know if this system has some common leak problem areas I should examine more closely?

Thanks in advance

Unfortunately, evaporator. Lot's of threads on this top.

as ever
Paul

Thanks. Did a search and found helpful information. Other posts suggest checking for dye on top of transmission below the AC condensate drain(s). Where exactly are these drain(s) located?

Thanks.

J. M. van Swaay

The drains go straight down out the bottom of the HVAC housing, through the transmission tunnel, and onto the transmission itself. There are two drains, one each on the passenger and driver side.

I've attached a photo showing a 124 wagon with the dash and hvac housing removed. The red arrows indicate the drain holes through the transmission tunnel. For reference, the gold box rear of the drains (it's the accelerometer for the airbag) sits directly below the radio in a fully assembled car.

Good luck,

- JimY

JMO but before you start tearing you car apart or taking it to the stealer I think I would try one of the sealers that are out on the market to save you doing that job! Did some reading on them and they sounded very promising! Have some good testamonials! I think before I tore apart my car to try and fix a leak I would give this stuff a try! Not that expencive! And no I do not sell the stuff ! just passing on the info! Check out this site !

# "We have installed Super Seal Plus in over 20 A/C systems in various makes and models, including Mercedes Benz. Super Seal Plus has worked very well for us. It is a great product!"

Smokie

http://www.dugcosupply.com/supersealpro.htm

Thanks for the picture. By the way, how long did this project take? I have the service manuals--looked them over and the job looks doable but time consuming. About the stop leak--certainly an option to consider, but not without risk. Some AC techs will not work on a system serviced with stop leak because it can be very damaging to reclaim equipment. Also, in some cases the stop leak stuff can gum up compressors, expansion valves, filters..... Would only consider stop leak for an evaporator, and then only if you are willing to risk having to later not only replace the evaporator but other components as well. If there are other considerations, I'm all ears. (or eyes in this case as I'll be reading them on a computer screen)

Thanks for some very helpful replies.

J. M. van Swaay

It's a 20-25 hour job for a first time DIY. As you surmise, not actually all that difficult, just tedious. I don't recall any impossible to access fasteners, and nothing is torqued to 300lb-ft for your enjoyment. Just take care not to damage any of the interior bits and life will be good.

I also have some first hand experience with the sealers. Mixed bag. The only one I would use is "cryo-chem." It's a two part formulation. First you add a drying agent to bind up all the water in the system. Run the system, then add the sealer (the sealers are all water activated epoxies). This stuff worked perfect. But I lost the compressor a year later, so can't say how long it will last. Don't think the compressor thing was related. Downside is it's an expensive treatment, and you need to change the dryer, recharge, etc. Parts cost is nearly the same as replacing the evap, though of course labor is much less.

I've also used a sealer which came in a single can. Not good, it activated in the dryer (which I didn't change, due to laziness). Cannot recall the name of that product. I just swapped in a new dryer, recharged, and it was good to go again; albeit with leaks.

My $.02 - replace the evap, it's the best solution long term.

- JimY

If you have to replace the evaporator, I'll 2nd that is not difficult if you are patient; just time very time consuming.

The manuals seem to indicate that the steering wheel needs to be removed; however, I could not get the bolt loose on mine, and had no problem removing the dash with the steering wheel in place.

I've found the best way to loosen that hex head bolt without tearing it up is to use an impact. Removes it quickly without damage; no counterhold is necessary.

I mark the shaft and the steering wheel with nail polish before I take the wheel off, that way I can put it back on in exactly the same position.

About ready to start disassembly. Printed all the procedures from the service manual CD's, but came across a few discrepencies. First, procedure 54-6015, removing and installing instrument cluster, references preceeding work procedures 61-105 (engine compartment panel removal) and 94-050 (noise encapsulation removal) I can't find either of these on the CD's. My guess is that this has to do with removing the speedo cable at the transmission prior to pulling out the cluster..... Also, the pictures from procedure 68-200 (removal of center console) show blower and air distribution knobs......my vehicle has pushbuttons. Is this panel removed the same way? Finally, procedure 68-150 (part B of removal of cover under instrument panel) refers to the glove box.....my vehicle doesn't have one (this space is now occupied by the passenger side airbag) Are there screws hidden somewhere......

I probably will be able to figure this all out as I progress with disassembly, but if someone has come across these same issues.........

Thanks again,

J. M. van Swaay

Regarding 61-105 (engine compartment panel removal) and 94-050 (noise encapsulation removal): I do believe this is related to removing the speedo cable. The speedo cable is attached at the back of the transmission; bolt has a 10 mm head. When I did this job, I did disconnect the speedo cable per the instructions. I put the car on ramps prior at the beginning of the job.

Regarding the the Euro style knobs vs. the US pushbuttons: that middle panel comes out basically the same way; you just don't have to remove the knobs and nuts first.

Regarding the glove box vs the airbag: there is a bolt with a 10mm head which holds in the air bag. The bolt goes straight up in the center of the passenger knee bolter. Follow the general instructions on airbag removal; (disconnect bat, then the red plug). After you remove the bolt, the air bag will slide out, and there will be some framework which needs to be removed.

Thanks again for all the great help. This forum has proven its worth many times over. I did finally find a procedure for the airbag removal. (91-680; chassis & body manual, body assembly jobs/airbags, 91-seats and rollover bar if you drill through the menu tree) Speedo cable was no brainer--disconnect from transmission and give enough slack to allow the instrumnet cluster to be pulled out of the dash...Encountered three minor problems, broke tab on ignition lock molding, (could have been avoided by better illustration in procedure 68-150) center console wood panel did not separate easily from window control pushbuttons, broke plastic rod end that connects dampers in vents leading to back seat area (could have been avoided by paying closer attention to procedure 83-554 step 8 of heater/ac box disassembly)

The whole assembly containing the evap and heat exchanger is now sitting on my workbench--will disassemble today.

By the way, I have read lots of posts on which evap to buy. Aluminum, Copper, OEM, aftermarket....is there a current consensus? Also, replacing the vacuum actuators was recommended, should I add these to my fastlane order?

Thanks again for all the help.

J. M. van Swaay

There is endless debate here on whether all-aluminum or all-copper is the way to go. It is my understand that either one would be fine. The key is to avoid an evap made of 2 different metals as this type suffers from accelerated corrosion. I believe OEM is made of both copper and aluminum.

As for the vac pods, I would do them while you're in there. Do it once and do it right, and hopefully you'll never have to pull the dash again.

There is an easy fix for that. Use a sheet metal screw with a head that is the proper size to slide into the space where the plastic piece used to. Then cut yourself a piece of vaccum hose and slide it over the rod and the thread on the screw and you have a flexible joint that works fine.

I use ACM evap. German made with expansion valve attached, they are all aluminum and cost about $250- 300.

As was said above change all six vacuum elements and consider a new blower with squirrel cages, I use ACM for that too.

Thanks for the easy fix. Any recommendations for sealing between the firewall and evap/heater box assembly?

Thanks,

J. M. van Swaay