Dodged the infamous 124 Evap Leak one more time
 

I have repaired several A/c leaks on my 88 300E in the last couple of years and just located another, but it still has the original evaporator with no signs of a leak.

Last year I replaced a leaking TXV, then a leaking condensor. It leaked out again and I thought that surely I couldn't be lucky a third time, but I was. I must be making the MB Gods happy.

This time it is CLEARLY leaking at the connection manifold on the compressor.

I know that the seal in there is two o-rings and I am assuming that they are just standard a/c O-rings. I have a very good Auto AC O-ring assortment at work, so I will bring it home next weekend and see if I have a couple that will fit.

Does anyone know if these are just standard a/c o-rings or is it a special size?

Thanks.

I got a reply to the post email from someone who was not identified. They must have deleted the post because it is not here now.

I thank the person for the information but I guess they thought that I was too stupid to measure the o-ring. The reason for the question is that I am not going to take it apart until I have the necessary seals in hand. Since I have yet to take it apart I can not very well measure it. My o-ring kit is not here and I wanted to know if I would need to go get some before disassembly.

I indeed have an ACSource o-ring kit and fully expect it to be in there.

Thanks,

if you don't mind me asking - whats your tried/true method for locating AC leaks? UV dye? or something better?

LarryBible,
It was deleted by me. The dimensions that I posted were for the GM/AC Delco/Harrison/Delphi/etc series compressors in the R4/A6/H6 models with O ring manifold seals. Since I then realized that it was your 300E with a Nippondenso compressor that was at issue, I retracted the post, since my posted dimensions were of no value.

My most common leak test method is UV dye. For really tough to find leaks though, the best method is to recover refrigerant, put in two oz. of R22, pressurize with nitrogen then use an electronic leak detector.

The nitrogen pressurizes the system everywhere so that leaks are more easily detected even on the low side and the R22 is MUCH more detectable by an electronic leak detector. This is a legal method because, I suppose, the EPA feels that it is better to release 2 oz. of R22 into the atmosphere than to have an ongoing leak of 12 or 134a.

Larry,
I have the nitrogen guage assy, but have yet to take time to buy a bottle. I picked up a tip from a guy on IATN. He presurises at about 70 lbs and then at around 200 lbs, because the low pressure picks up leaks at the hose crimps, and the high pressure picks up everything else.

I had an email this morning that indicated that Diesel Giant had posted the following to this thread:



"All refrigerants are chemical concoctions. A blend means that it is an
azetropic mixture and is the way to get the desired properties of a
specific refrigerant and engineer out what you dont want. As long as you
are not using an "near azertropic" mixture which will experience
fracternization if introduced in the system as a vapor. They must always be
charged as a liquid.

Using what many keep saying is a "blend" if it was used in the
application for which it was engineered. Freeze 12 was engineered with modern
technology to do just what R-12 does but with lower pressures. Same
idea with R-410a replacing R-22, except you must use different equipment
to handle the almost 100% increase in pressure with R-410a.

What most people dont understand about refrigeration is that it all
works basically the same. I could run R22 in the MB and get it just as
cool if I changed out different components. Point is that Freeze 12 is
designed to work in place with R-12 with better performance. Don't
listen to all the "sky is falling" types out there."




He must have deleted it since the time that I received the email.

Learning from books is a wonderful thing, but there is a point where this information must be put into practical use. THAT is where FREEZE 12 and the other snake oil refrigerants present problems.

Although it is not confirmed, I do NOT doubt that FREEZE 12 can work better than R12. Where the practical problem lies is with fittings and recovery equipment. BY LAW ALL systems are supposed to have the fittings SPECIFIC to THAT refrigerant. Unfortunately, out here in the real world AWAY FROM academia and theory, very few people use the correct fittings.

What this leads to is contaminated containers of refrigerant that must be destroyed which costs lots of money, not to mention lots of loss of otherwise usable refrigerants.

PLEASE!!!!!!!!!!!!!!!!!!!!! If you wish to use these junk refrigerants, use the correct fittings and label the vehicle PROPERLY, to prevent some poor guy from sucking this crap in with a legitimate refrigerant and contaminating his entire container!!!!

Larry,
I think calling them junk refrigerents is a little harsh, but I do agree with you about proper labeling. Since we can preach it, and it won't happen I got an early model recovery only machine for next to nothing, and use it to suck out the old stuff whether it be propane or what. It is a PITA to use the refrigerent identifier. Now my only concern is if the yayhoo put some kinda bubble gum stop leak in the system to keep from paying for repairs.

If I were ruler of the country, I'd make refrigerent a controlled substance that could only be obtained by licensed individuals with severe penalties for those who abuse the license.

Autozen,

I'm pretty close to your thinking.

You can get a leak stop detector. That means that to protect your recovery equipment, you need about $2000 worth of identifying equipment, a refrigerant identifier and a leak stop detector to protect several thousands of dollars worth of equipment.

I don't have an identifier, so I just don't let my recovery machines get anywhere near a car that I don't know anything about.

The people who put in refrigerants without proper labeling and fittings usually have no idea what kind of problems they are causing for others or they just don't care.

Have a great day,

Peter:

As you know, they did that with R-12, but for $20 or so, and an hr. online, a complete know-nothing can take an open book test and receive a 609 certification.

This test focuses only on environmental laws(at least the one I took from Macs 8 yrs. ago did), but requires no legitimate knowledge of a/c systems.

The govt. left a back door in place for those who wanted it bad enough.

If R-12 was REALLY the earth-killer that the tree huggers have painted it up to be, it would be gone.

My 2 cents.