Replaced the evaporator core in my 1987 300E over the past few days without the use of a manual. The results of my research here was all that I needed. The worst part of the job was getting the AC compressor to restart when adding refrigerant, it refused to kick in. After checking fuses, relays, sensor switches, vaccuum lines, bypassing switches to make sure the clutch worked, I was about to give up until I spent another hour here and found a post that said to MAKE SURE THE TACH IS RECONNECTED, OR THE RELAY WONT KICK THE COMPRESSOR CLUTCH IN. Well, since I tore out the dash, and was not about to put it back together without checking everything first, needless to say, my tach was disconnected. That was my problem, reconnected it and everything was fine. Many thanks to all of the posters here.

Congratulations-- did you calculate how many hours this took you?

I have to do vacuum pods on my CE and am just a bit curious how long the entire job took. I figure the pods will take roughly half the time of the entire job.

__________________
1989 300ce 129k
( facelifted front,updated tail lights, lowered suspension,bilstein sports, lorinser front spoiler, MOMO steering wheel, remus exhaust,stainless steel brake lines). (Gone)

1997 s320 154k (what a ride). Sold with 179k miles. Replaced with Hyundai Equus

1994 e320 Cabriolet 108k



1972 280se 4.5 153k Owned for 12 yrs, sorry I sold it


[/SIGPIC]

I've never done the evap, but when I did the pods on my 300E last year, it took me 18 hours over three days. This was doing it for the first time, with the shop manual, but in no particular hurry, and with a cold to boot.

I did pods in about 15, but I also put a heater core in at the same time without pulling the box. I think the book time is a little over 15 hours for the evap, and the pros that do it frequently can probably hit that time.

Good luck,

Can you see the evap with just the blower motor out? I need to check mine to see if it has nasty dirt buildup causing poor cooling. I just pulled my dash out last week for the first time to check all the pods, took me 3.5 hours out and back in. My A/C ran without the instrument cluster hooked up at all. If you see this Larry Bible, did you get my message?

I'm not sure what model you are working on, but on the 87 300 e, the blower is behind the evap.

It took me about 20 hours, including several hours spent here, and all over the net doing research. I also did not remove the box, as I could not find instructions that complete that mentioned breaking the seals from the firewall. After screwing around for an hour, with all of the clips, bolts, and screws removed, I Dremeled off part of the right side of the box in order to slide out the evaporator! I used roofing Butyl sealant caulk to seal it back up, and held it in place with heavy duty HVAC metal tape until the Butyl set up.

Glad I used the dremel, and restrained myself from going for the sledge hammer.

I am not an automotive tech, but I have done almost all of my own work over the past 30 yrs. Exceptions include: Auto trans rebuild, strut replacement, or anything that MUST be done with a crane and a lift.

Thanks again for your help that I gleaned from other posts.

My bad....91 300E.
Im hoping to see the evaporator when taking out the blower motor, so I can check for gunk or buildup on the evap causing poor cooling.

You can see most of the front side evaporator from the engine compartment, between the firewalls, if you remove the wiper assemply, top of heater box, and the blower. I did this to inspect the evap prior to replacement in my '95 E320.

__________________
as ever
Paul

1989 560SL
1987 300SDL
1987 300TD
1983 BMW 633CSi
1972 280SE 4.5

Does top of the heater box require the dash removal?
Anyone ever see a bad epansion valve/ symptoms?
I just did some homework on the pressures and temps according to the MB cd and mine are off with correct amount of freon.

MB spec: Ambient 104 F / 40% Relative Humidity, High Blower Speed=
Low side 29-36 psi High side 377-391 psi Duct temp 55-60F.

Actual readings Low side 45-47psi High side 220-235 psi and 80-83F duct temp. That is with the fans on high and helper fan.
Noticed last night that the guages will slowly fluctuate about 10 to 20 psi. the high side will go up 20 while the low goes down 8 or 10 at the same time, then they go the other way and over and over but like 3 or 4 times a minute.
This morning it was 86F ambient 38% RH on the way to work and on low it only blew 65F....same as when it was 107F yesterday. So Im wondering if the expansion valve is limiting the freon to the evap to 65F on low blower or any blower for that matter , or if the evap is dirty and clogged on the outside, but it blows hard.

Actually Ill just start a thread on the expansion valve problem.

You can remove enough of the box (not sure if this is considered the top, back etc) from the engine compartment side to remove the fan; then the evaporator is visible. It job 83-556 in the climate control manual.

__________________
as ever
Paul

1989 560SL
1987 300SDL
1987 300TD
1983 BMW 633CSi
1972 280SE 4.5

Cool, If it comes to that Ill check it. And lube the stupid squeaky blower motor too.

gpracer,

Yes, the dash comes off for access to the heater core. If you replace ONLY the heater core without removing the box for an evaporator job, it's kind of challenging, but doable. Take lots of care to get the heater core seals in place because you don't want to pull the dash a second time due to a leak.

When I put my dash back on I sweated bullets until I knew that the new heater core was not going to leak.

The pressures you listed in THIS thread definitely do not indicate a bad expansion valve.

Good luck,