ac upgrade... help me help you. - Page 2 - PeachParts Mercedes-Benz Forum

Adriel · #16 09-07-2015, 01:22 PM

So, am I to understand this is no longer going to happen?

Having lot of trouble getting the condenser in... Once in, will need hoses.

Junkman · #17 09-07-2015, 03:09 PM

84SD needs a refurb (and has no gas so I don't have to consider breaking the law). What do you need there?

vstech · #18 09-08-2015, 08:27 AM

As soon as I enter my slow period, I will start ordering hoses and fittings and make some progress on the coil. Bear with me.

jay_bob · #19 09-08-2015, 03:01 PM

I might want to be your 1st gen 124 guinea pig. Seriously considering this or going back to R12. Columbia just too stinkin hot for R134 and a serial condenser.

leathermang · #20 09-08-2015, 03:29 PM

Quote:

Originally Posted by jay_bob

I might want to be your 1st gen 124 guinea pig. Seriously considering this or going back to R12. Columbia just too stinkin hot for R134 and a serial condenser.

In the mean time... have you cleaned and straightened the fins on both the condensor AND the radiator ? Are you sure all your fans are working well and when they should ?
Have you cleaned your Evaporator fins.. .up inside your dash ...that is Half the system.... and it is often neglected.... like for decades... people who have done that unpleasant task... have really enjoyed the results...
just those two things might get you go better working weather...

jay_bob · #21 09-08-2015, 03:54 PM

Thanks for that

I know the rad and condenser is clean, John and I installed that about 3 years ago. But I will double check.

I had tested fan operation back when I got the car running but it would be good to validate it's still good. I did have a bad resistor and had to replace it about 18 months ago.

I imagine the evap is filthy, I will have the dash apart sometime in the near future to do a dual airbag and interlock shifter upgrade from a 91 I found at the yard. When I have it all apart I will crack the blower case and see how it looks.

vstech · #22 09-08-2015, 04:01 PM

Quote:

Originally Posted by jay_bob

I might want to be your 1st gen 124 guinea pig. Seriously considering this or going back to R12. Columbia just too stinkin hot for R134 and a serial condenser.

Keep in mind that condenser isn't stock. .. it's about 2" short iirc... and... it WAS clean 3 years ago... only takes one year of leaves to cause issues...

leathermang · #23 09-08-2015, 04:14 PM

Quote:

Originally Posted by jay_bob

.....I imagine the evap is filthy, .....

Probably one of the surest bets which can be made on these old cars... all sorts of things usually done to the rest of the system over the years.. but almost never do those evap fins get addressed...
Nice that it is ONLY labor for the most part.... not like replacing a compressor... and the refrigerant does not have to be taken out to do it....
Very good instructions with pictures in the archives...

jay_bob · #24 09-08-2015, 05:07 PM

John if you'll recall we decided to go with 134 since the PO did a conversion and put the adapter caps on the 12 fittings. I was concerned that trying to remove the adapters and go back to 12 would destroy the hose. Now that you have the ability to make new hoses it might be worth it to try going back to 12.

Depending on finances I am going to see if I can afford a proper condenser and let you have yours back. So should I look at getting a stock condenser and run 12 or go to a PF and stay on 134.

leathermang · #25 09-08-2015, 05:26 PM

Jay Bob,
Screw up your courage and attack that evap Fin problem..... those other things will not provide much satisfaction if your fins are a major problem.... and the chances they ARE.
It is harder and harder to find R12 service places... you might be just fine with your current refrigerant..with clean evap fins and good fans..... and you can find service places for that one...

jay_bob · #26 09-08-2015, 05:48 PM

I'm not afraid to pull the dash on a 124, done it about a 1/2 dozen times between my car and the junk yard.

I have some heavy traveling out of country the next couple three weeks. When I get back I will try to get that evap clean first and see how that does. We should still be in the late September heat when I get back so I will be able to see how much of an improvement it makes. The air flow is not what I expect out of the vents so I imagine it will help greatly.

I will also check out the vacuum pod manifold and make sure all my air doors are working right while I have the dash apart as well.

leathermang · #27 09-08-2015, 05:58 PM

I am sure you will be pleased with the results....
I think DWMorrison has great info for once you get inside the evaporator...

jay_bob · #28 09-27-2015, 06:51 PM

Quote:

Originally Posted by jay_bob

I'm not afraid to pull the dash on a 124, done it about a 1/2 dozen times between my car and the junk yard.

I have some heavy traveling out of country the next couple three weeks. When I get back I will try to get that evap clean first and see how that does. We should still be in the late September heat when I get back so I will be able to see how much of an improvement it makes. The air flow is not what I expect out of the vents so I imagine it will help greatly.

I will also check out the vacuum pod manifold and make sure all my air doors are working right while I have the dash apart as well.

Well I finally found some time to work on the car today.

I went into the blower box from the front from under the wiper. I could see the evaporator, it was totally covered in dirt.

So I got a can of Scrubbing Bubbles bathroom cleaner and slid a pan underneath the car to catch the runoff.

The foam turned black when I sprayed it. I hit it several times, let it foam up then dissolve, and hit again. Then using a 1/4" tube fed from my (cleaned out) MityVac oil extractor set to pressure mode, gently dispensed a couple gallons of water to flush the evaporator. I repeated this about 3 times and the evaporator is nice and shiny now.

I checked the condenser, it is clean. My son parks in the garage and there are no trees near the high school parking lot.

After doing this there was a marked improvement in the air flow. It smelled a little like Scrubbing Bubbles but it smells a lot better than it did before.

I also pulled the glove box and verified all 7 control lines hold good vacuum. The air flow changes modes as expected per the sequence of operations in the service manual chapter 83.

It only got up to 70 degrees and no sun today so not a good day to validate performance. We should get another warm spell before the end of fall so I will be able to see how much all this helps.

leathermang · #29 09-27-2015, 06:55 PM

If you have any kinds of smells that might be from inside the evaporator box or air tubes... you can spray a mist of Febrez near the intake of the AC when the blower is on.. works fast and great....