Common locations for refrigerant leaks?

[MMWA]

On a 1990 w124 - please dont tell me evap coil ;)

Previous owner seems to remember being told it was the compressor shaft seal leaking which is no big deal, I'll just buy a new compressor - removing the dash sounds like a bit of a nightmare if it is the coil though.

I'd like to actually drive the car this summer without being incinerated inside

[Greg in Oz]

Compressor and hose connections are common places for leaks on the W124 as is the evap... Oh wait, you said not to tell you that.

[Ivanerrol]

Get a AC service guy to put some green marker dye in - that is if you have any gas still in there.
I had both my cars filled up with gas last year plus adding the dye.
The W202 compressor leaks like a sieve from the front shaft seal.
The W210 compressor has a slight leak.

The cost to have these compressors overhauled is ridiculous. I just bought a second hand compressor.

You can buy a reconditioned compressor from the U.S. cheaper than getting your old one redone. This includes the cost of the shipping.

Make sure you get the right compressor for your car.

[MMWA]

Brand new genuine Denso compressor on the way from the USA for $371AU delivered. Pretty sure you couldnt even buy one for a falcadore for that much in ripoffalia. ;)

I will fit it and have it charged up at my local and see what happens. If the evap coil leaks so be it - I will take on the epic task :boohoo:

All of the reports of leaking evap coils i could find using a google search were on late cars that came from the factory with R134a, Though the part number for the evap coil according to my EPC is the same for My R12 system and the later version anyway. I remain hopeful i will escape this horrific job. though I have to remove the dash at some stage anyway as one of the vacuum pods leaks so I'll change them all.

[Greg in Oz]

So are you staying with R12 or changing to R134a or something else? I have R134a in the 300TE, 190E 2.3 (auto) and the 190E 2.3-16. The 500SLC and 190E 2.3 Sportline (manual) are still running R12. All the R134a cars currently have cold air as does the 500SLC but my 190E Sportline (my daily drive) needs refrigerant. The problem now is finding anyone who still carries R12.

I have been considering converting them all (or the R12 cars at least) to hydrocarbon refrigerant such as "Minus 30" or "HR12" from HyChill. I know some on this forum have converted to it and from what I understand are happy with it. Apparently the hydrocarbon refrigerant works much better than R134a and possibly even better than R12 and it is compatible with any compressor oil. I guess the only issue is still the number of places who stock the HyChill refrigerant. If my understanding is correct, I believe it may be even possible to buy it without needing a refrigeration licence for DIY use. I guess it really is no different to buying gas for your barbecue.

[Ivanerrol]

F.W.I.W.

The compressor in my W202 was changed out at a stealership when owned by the P.O.
The stealership installed the wrong compressor. For the W202 there is a 3 bolt unit and a 4 bolt unit. My car originally came with a 4 bolt unit. The stealership fitted a 3 bolt unit. The problem is that there is
no anchor point on the block for the rear bolt hole on the 3 bolt compressor. The compressor is only held in there by the 2 front bolts. Hence strain on the pulley and the front seal causing the gas and oil leak.

I approached a Bosch AC specialist to have the Compressor resealed. He was fine with doing the reseal as long as I uninstalled and then reinstalled the compressor myself
The cost for the reseal was going to be around $150.00 (Front seal only :Doh: ) Then the specialist would regas the system - for more $$$$

Since I found that this compressor was only being held on by the 2 front bolts I gave this idea away.

The easiest approach is to do what M.M.W.A. suggested - get a brand new correct spec unit from the U.S.of A.

I went down to the stearship where the changeover compressor was fitted and have them look up the records for the car. They still had the service records but not the actual detail of what was done (something to do with computerisation of the records) I pointed out the error of installing the wrong compressor - all I got was a grin in reply. :liar:

[MMWA]

Previous owners last charge was hydrocarbon refrigerant so I'll do the same.

Plus i dont like the idea of R134a in a system originally designed for R12. Perhaps if the later R134a condenser & tx valve was installed and fans modded to run with the compressor but no. Thats not a modification I want to do, nor do i want anyone touching my car other than myself, after what i've seen I simply do not trust them. (especially a well known Mercedes "specialist" in perth who is nothing but a butcher and a thief)

[Greg in Oz]

I also prefer to stick with R12 in systems originally designed for it. R134a means higher pressures and inferior thermal performance. My 190E 2.3-16 and 300TE both had been converted to R134a prior to me purchasing them and the 190E 2.3 auto being a 1992 model presumably came with R134a from new. My 500SLC and 190E 2.3 Sportline came with R12 and I have kept them that way. When the Sportline needed a new TX valve, receiver-dryer and compressor reseal, he asked if I wanted to stay with R12 or convert to R134a. He commented that if it was his car he would stay with R12. Only now with the lack of places that carry R12 is it becoming a problem, hence my interest in conversion to hydrocarbon refrigerant.

My understanding of your recent post suggests you will buy the hydrocarbon refrigerant and charge the system yourself, is that correct? I am interested to learn more about using hydrocarbon from anyone with experience of it, including charging the system as a DIY job. There is something very convenient about being able to do these jobs yourself at times that suit you.

[SantoC]

Does anyone know when Mercedes had its change over period from R12 to R-134a?

[Ivanerrol]

Does anyone know when Mercedes had its change over period from R12 to R-134a?

Depended on the market. So not Mercedes specific.
So depended on the build date on your car or whether or not your car is a grey import.

Update '90 cars (W124) generally came with R134 but it maybe a generalization. My update '90 Japanese import W124 ran R12. I could still source R12 in Melbourne a year ago.

[scorchi0]

Does anyone know when Mercedes had its change over period from R12 to R-134a?

Update '90 cars (W124) generally came with R134 but it maybe a generalization. My update '90 Japanese import W124 ran R12. I could still source R12 in Melbourne a year ago.

I believe the update cars also received a larger evaporator to combat the reduced performance of R134a.

I have to say my 1991 300TE's A/C is one of the coldest I've ever had and is infinitely better than my old 1987 230TE.

Trent

[Hendrik]

I believe the update cars also received a larger evaporator to combat the reduced performance of R134a.

Trent

I have that hydrocarbon stuff in my system and it works pretty well but am having some issues with the compressor cutting out, I suspect that the aux fan is not coming on as it should.
However I would say that a fair few older evaporators are partially clogged up and they are a pain to get to.
Perhaps one day I'll get around to putting in a new evap and new pods and doing a good write up on the process.

[scorchi0]

I believe the update cars also received a larger evaporator to combat the reduced performance of R134a.

Trent

I have that hydrocarbon stuff in my system and it works pretty well but am having some issues with the compressor cutting out, I suspect that the aux fan is not coming on as it should.
However I would say that a fair few older evaporators are partially clogged up and they are a pain to get to.
Perhaps one day I'll get around to putting in a new evap and new pods and doing a good write up on the process.

I had problems with the compressor cutting out in the 230 as well. Turned out to be the Klima relay, but also be aware that there is a speed sensor in the compressor as well that can be a problem. It's for protection against seizing. If the compressor seizes, then there will be no signal from the speed sensor so the relay cuts our the compressor clutch.

[MMWA]

my march 1990 car is an aussie delivered version and is fitted with an R12 system.

The part number for the evap coil is the same in early and late cars, that doesn't mean though they weren't different once upon a time. The condensors and TX valves will be different for sure.

BTW I pulled a vacuum in my system 48 hours ago and its being lost. Atleast I will be able to know for certain if my new compressor has made a difference when it arrives before i go spending money on a recharge :dance:

[Hendrik]

Just thinking out loud, my air con has been a bit funky, I may have mentioned this, my suspicions are that either the Klima relay is being stupid or the system is not telling the aux fan to come on.
The thing is if is the pressure switch would be it be an idea to wire in a relay into the power to the compressor. so that whenever the compressor engages the aux fan comes on?
Problem being to replace the pressure switch the system will need to be regassed.
The compressor is not supposed to run all the time, only until the right temp is reached and then stops until the temp rises again.

[Greg in Oz]

Does anyone know when Mercedes had its change over period from R12 to R-134a?

Depended on the market. So not Mercedes specific.
So depended on the build date on your car or whether or not your car is a grey import.

Update '90 cars (W124) generally came with R134 but it maybe a generalization. My update '90 Japanese import W124 ran R12. I could still source R12 in Melbourne a year ago.

My 190E 2.3 Sportline is mid 1990 and it still runs R12. Our 300TE is also mid 1990 and has R134a however I think it may have been retrofitted. Our 190E 2.3 auto is a very late 1991 build (registered 1992) and has R134a.

Just thinking out loud, my air con has been a bit funky, I may have mentioned this, my suspicions are that either the Klima relay is being stupid or the system is not telling the aux fan to come on.
The thing is if is the pressure switch would be it be an idea to wire in a relay into the power to the compressor. so that whenever the compressor engages the aux fan comes on?
Problem being to replace the pressure switch the system will need to be regassed.
The compressor is not supposed to run all the time, only until the right temp is reached and then stops until the temp rises again.

Yes, to replace the pressure switch will mean the need to re-gass. Obviously fitting a relay to run the condenser fan whenever the compressor runs could be a fix to avoid needing to replace the pressure switch but that would see the fan run needlessly when movement of the car pushes sufficient air through the condenser. Normally the condenser fan is only needed in slow moving traffic.

[Hendrik]

Yes, to replace the pressure switch will mean the need to re-gass. Obviously fitting a relay to run the condenser fan whenever the compressor runs could be a fix to avoid needing to replace the pressure switch but that would see the fan run needlessly when movement of the car pushes sufficient air through the condenser. Normally the condenser fan is only needed in slow moving traffic.

This is more of a stop gap measure if it turns out that it is the switch, not a permanent solution, also the car does mostly short runs and does spend a fair amount sitting in traffic.
I was just running it past you guys in case there where any red flags mean stop type problems with my thoughts.

[MMWA]

40 hours under vacuum with new compressor installed, no loss of vacuum, this was not achievable with old compressor installed.

I may well be able to thank the MB gods for not making me change a W124 evap coil.

[MMWA]

Seems Evap leaks are so common in benzes they made a test rig for test it on its own for 100% confirmation it is at fault.

The WIS is awesome.

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[Ali_Boz]

Hi Gents,

The A/c in my 300TE (built mid '91, running R12 gas) is having issues with the cold air only being as cold as the outside air ie night driving a/c is cold and day driving the a/c is warm. My indie mechanic says it needs to be converted to R134a but I'd rather keep an r12 based system due to the cars system being r12. But on the otherhand r134a is everywhere and most places do it with summer pretty much here I'm sitting on the fence and i just want a functional a/c system.

[Pete49]

For what its worth my 123 280TE needed to be re-gassed due to a damaged hose so I replaced the drier and hose vacuumed the system and re-gassed with Hychill 30 and it works great. The Hychill decreases pressure unlike R134a and as a bonus Hychill doesn't need a ARC licence as yet so home DIY guys can do it themselves with care. Plenty info on the net and vac pumps and gauges available on evilbay. :dance: Check out the Hychill website for all the info you need. I've now re-gassed the wifes w123 300D and my Jag 420G and reckon its the bees knees. :occasion5:
Pete

[Ali_Boz]

I'd just some reading about the hychill 30 and I think ill go down that path. just need to figure out what needs the be replaced in my system and use the hychill 30, most likely a new receiver dryer.

now re-gassed the wifes w123 300D and my Jag 420G and reckon its the bees knees.

so you're satisfied with the hychill 30? what was the cost of regassing with it etc

[MMWA]

Epic thread dig.

I did all the work myself. I have the tools and a large cylinder of hychill I use, its much cheaper than buying the individual cans but It's not just been used in my own car so may not be economical for everyone. Everthing other than the hoses themself the condensor and the evap coil is new.

3 years on and still freezing cold. I dont drive around with temp wheels at max cold like some r134a conversions have to, nor did i have to butcher the original aux fan wiring. It all functions as intended and maintains a comfortable temp when both sides set to 22c and vents pointed away from my face.

Only issue ive had was a burnt out heater solenoid coil which fried my ac control panel. Good used panel and brand new genuine solenoid and never missed a beat again.

Going to be doing it all again on my other w124 soon enough anyway.

[Pete49]

I'd just some reading about the hychill 30 and I think ill go down that path. just need to figure out what needs the be replaced in my system and use the hychill 30, most likely a new receiver dryer.

now re-gassed the wifes w123 300D and my Jag 420G and reckon its the bees knees.

so you're satisfied with the hychill 30? what was the cost of regassing with it etc

Yep more than happy with it. :dance: When I did the 2 cars I bought the cans but will be looking at buying a a larger cylinder as I have 5 cars to maintain so much better deal. The can cost me $50 and the drier about for the Jag about $25. Can't remember the Mercs around $50-60 for the dryer i think.
Pete

[Ali_Boz]

$50-60 for the dryer i think

I can get a hold of a drier for around $40 and a service centre in melbourne can recharge and 'retrofit' hychill minus 30 for $150 but I'd rather that than a r134a conversion, that's for sure.

[Cal]

So if you wanted to convert a W124 to HyChill, what hardware would need to be replaced?

[Pete49]

Like most cars the only part is the a/c dryer as they are a filter sort of. Its all I had to replace. Have a google and you'll be surprised how simple it is do do.

[pina4greg]

Epic thread dig.

I did all the work myself. I have the tools and a large cylinder of hychill I use, its much cheaper than buying the individual cans but It's not just been used in my own car so may not be economical for everyone. Everthing other than the hoses themself the condensor and the evap coil is new.

3 years on and still freezing cold. I dont drive around with temp wheels at max cold like some r134a conversions have to, nor did i have to butcher the original aux fan wiring. It all functions as intended and maintains a comfortable temp when both sides set to 22c and vents pointed away from my face.

Only issue ive had was a burnt out heater solenoid coil which fried my ac control panel. Good used panel and brand new genuine solenoid and never missed a beat again.

Going to be doing it all again on my other w124 soon enough anyway.

Is there somewhere you would suggest to inspect and repair my ac if necessary here in Perth... appears a complicated system so should I give the Star shop a go????

[Tony From West Oz]

So if you wanted to convert a W124 to HyChill, what hardware would need to be replaced?

Why would you convert a car designed for R134a to Hychill?

[Pete49]

Tony lower pressures and better cooling is the reason most swap gas. My 280TE was on R12 which was changed to R134a by the previous owner and was not that cool whereas with the Hychill its much cooler as I found out when it needed re-gassing. Also Hychill doesn't require a ARC license to do your own. If it didn't need re-gassing I wouldn't have changed until it was needed. Just my 2 bobs worth.

[MMWA]

Epic thread dig.

I did all the work myself. I have the tools and a large cylinder of hychill I use, its much cheaper than buying the individual cans but It's not just been used in my own car so may not be economical for everyone. Everthing other than the hoses themself the condensor and the evap coil is new.

3 years on and still freezing cold. I dont drive around with temp wheels at max cold like some r134a conversions have to, nor did i have to butcher the original aux fan wiring. It all functions as intended and maintains a comfortable temp when both sides set to 22c and vents pointed away from my face.

Only issue ive had was a burnt out heater solenoid coil which fried my ac control panel. Good used panel and brand new genuine solenoid and never missed a beat again.

Going to be doing it all again on my other w124 soon enough anyway.

Is there somewhere you would suggest to inspect and repair my ac if necessary here in Perth... appears a complicated system so should I give the Star shop a go????

Do yourself a favour and forget the mentioned place and never ever remember it again. North of the river where you are you should probably consider the place in Balcatta, behind bunnings. I cant remember the name of it. Its on the road directly behind bunnings on balcatta road. I hear good things from customers. I do everything myself so I wouldn't know.

w140 evap coils fail and leak, if this is your problem you're up for a repair in excess of the value of the car unless you do it yourself. It can be pressure tested by them if they have the tools.