124 Evaporator Replacement 1995 300D - PeachParts Mercedes-Benz Forum

diesel85 · #1 10-05-2018, 12:28 PM

Hello Everyone,

I KNOW there have been multiple posts on this, but the ones I've seen are more than 5 years old. I just acquired a 1995 300D that I BELIEVE needs the dreaded evaporator replaced. I'm looking for tips, tricks, videos and most importantly the FSM pages on doing the job. Any advice is welcome. Thanks!

Also, I live in the 95825 zip code of Sacramento, CA. I would WELCOME and even PAY for someone near me who has performed the job in the past to assist with the replacement.

Maxbumpo · #2 10-05-2018, 01:19 PM

Here's my advice: consider trying one of the products that seals the leak, so you don't have to replace the evaporator. Cliplight Super Seal Premium for instance.

Cliplight - Super Seal Premium - The Classic Auto A/C Sealant

If your evaporator leak is slow enough, like it takes a couple weeks or longer to require a re-fill of the r134, a sealer will probably work for you.

Research required! Study up. I think the steps needed for high rate of success:

(1) Empty the system - recover the refrigerant.

(2) Replace the filter / drier and any other components that you're planning to replace, fill system with dry nitrogen and small amount of tracer gas like r134, pressurize to ~200 lbs, check for leaks with a sniffer. No leaks other than the evap? Proceed.

(3) Draw a vacuum, follow the directions to fill system with Sealer and r134.

(4) Keep the car running with the AC running on high for the required time to circulate the sealer - I think it is a minimum of 30 minutes.

shertex · #3 10-05-2018, 01:48 PM

Ditto. I used Cryoseal on my 92 300D...worked well.

SSR R-134a Kit Repairs Leaks In Mobile Air Conditioning Systems

Less expensive and worth trying are the products from esrefrigerants.

https://www.es-refrigerants.com/products/Default.asp?id=4&t=refrigerant-support-fluids&&Trying=ON

Maxbumpo · #4 10-05-2018, 02:29 PM

I like that Cryoseal adds the step with their de-hydrant product, which is added after a new receiver / drier is installed and before the sealer is installed.. This ensures that there is no water in the system and that the sealer doesn't activate in the wrong place (like in all the water trapped in the receiver / drier). I actually bought a similar product from a different maker to use in conjunction with the Cliplight sealer I already have on the shelf.

I've got two cars with leaking evaporators, I'm going to try this stuff before I go to the extreme of pulling the dash and replacing an evaporator.

Hit Man X · #5 10-05-2018, 02:35 PM

I did pods in my old 300E, I spent 10 hours start to finish to R&R the dash my first time. I cannot see it taking much longer to pull the box and swap the evap, heater core, blower, and popping it back in the car.

The job is really blown out of proportion how difficult it is to perform.

Label everything and remember its location or take pictures with your phone.

I THINK I saw a video, sped up, of a guy doing this job on youtube.

I did not do the evap as it was cheaper for me to keep shooting refrigerant in the thing once a year.

Maxbumpo · #6 10-05-2018, 02:59 PM

Replacing the pods is a good reason to do this job, but if you're in the mood of avoiding the work for that reason, and only the center vent pod is the problem, then you can pull the center dash vent grill, and reach in with a spare exhaust doughnut and force the door open permanently, leaving the doughnut between the door and the heater core. Pull the instrument cluster, remove screw on left side of vent grill, open glove box and remove screw on right side of vent grill, use 5mm (or 4mm?) hex key to loosen the screw inside the vent grill assembly that connects the open / close dial to the manual door, and you can get to the place to install the doughnut.

renaissanceman · #7 10-05-2018, 03:13 PM

Sealers make me very nervous...I have an evaporator leak on my W124 as well but I'm not sure if I'd be willing to roll the dice on using a sealer. I wish my A/C system was completely leak free...but it tends to hold a charge all summer, and then leak mostly our over the winter.

diesel85 · #8 10-05-2018, 04:26 PM

I'm leaning towards rernaissanceman's perspective. I see the sealant as a temporary fix. Sooner or later, I'll have to replace the evaporator. A sealant will most likely cause further damage to the other components of the system. The car only has 110K on it, and I plan to drive it until the wheels fall off!!!!

shertex · #9 10-05-2018, 05:11 PM

Quote:

Originally Posted by diesel85

I'm leaning towards rernaissanceman's perspective. I see the sealant as a temporary fix. Sooner or later, I'll have to replace the evaporator. A sealant will most likely cause further damage to the other components of the system. The car only has 110K on it, and I plan to drive it until the wheels fall off!!!!

A sealant like Cryoseal will most certainly not cause any damage to anything. But the random can of stuff you pick up at Walmart might.

renaissanceman · #10 10-05-2018, 06:13 PM

Quote:

Originally Posted by shertex

A sealant like Cryoseal will most certainly not cause any damage to anything. But the random can of stuff you pick up at Walmart might.

I wish I knew this to be a fact -- I'd try it out right away so.

Zulfiqar · #11 10-05-2018, 06:21 PM

Quote:

Originally Posted by diesel85

I'm leaning towards rernaissanceman's perspective. I see the sealant as a temporary fix. Sooner or later, I'll have to replace the evaporator. A sealant will most likely cause further damage to the other components of the system. The car only has 110K on it, and I plan to drive it until the wheels fall off!!!!

The front wheels literally fall off if you dont change the balljoints in time.

btw - owning it till the wheels fall off is a tall undertaking. These cars when maintained will roll near damn forever, But if you short change on the upkeep, they fail quicker than any italian vehicle.

I have done this job - its just lots of small work, no grunt work etc. But the repair is surely a good one. - OTOH, a can of cryoseal does work - if the leak is not too terrible and you follow the instructions to the dot.

But if you do plan to keep it forever - I would go ahead and replace the evaporator.

jay_bob · #12 10-08-2018, 10:35 PM

I tried the sealer in my W210. It did not help.

I ended up rebuilding the entire system after the compressor seized in the spring of 2016.

http://www.peachparts.com/shopforum/diesel-discussion/377507-w210-compressor-seized.html
I have not had to touch it since (as in I have not added any refrigerant to it) and it still works flawlessly even in our brutal SC summers.

Maxbumpo · #13 10-09-2018, 08:05 AM

Jay Bob - please tell us more about your experience with the sealer that failed.

jay_bob · #14 10-09-2018, 08:23 PM

This is the 1998 E300 that my younger son currently drives. I bought it in March 2013 from forum member Citationtech, and I noticed the the a/c was weak driving it home from Maryland. I stopped by John VStech’s place in Charlotte on the way home and he charged it up. I was having to top it up constantly.

In July 2014 we had the gathering at the biofuel plant in Winnsboro. John was there and he applied the sealant.
It got better but not perfect. Still had to add a couple cans per summer and it struggled on hot days (of which we have none of those in Columbia, hehe)

Finally in the spring of 2016 I was driving home one night and the compressor seized tight. Tore the whole system down and built it back up again. Evaporator was clearly leaking. Oil stains and green goo in bottom of evaporator box.

Got John to charge it up the weekend after Memorial Day 2016 and I have not had to touch it since.
System has had no problem maintaining vent temps in the 30s no matter the weather since I fixed it.

diesel85 · #15 10-10-2018, 11:52 AM

Jay_bob, do you remember what specific product was used to "seal" the leak?