How can I have AC repaired without being taken to the cleaners? - Page 3 - PeachParts Mercedes-Benz Forum

LuckyEddie · #31 05-02-2009, 12:30 PM

This could get interesting

How manny feel that "ill eagle" is a sick bird????????????

Have a nice day

I stoped using the flame leak detector a few years ago. Allied was what some were called and I knew the danger.

Dee8go · #32 05-02-2009, 01:22 PM

I wasn't aware that dry cleaners were doing air conditioning repairs now. What'll they think of next?

2.5Turbo · #33 05-02-2009, 03:36 PM

I really like how the EPA says venting 134a is illegal while every "canned air" computer duster is full of the same stuff...

Skid Row Joe · #34 05-02-2009, 03:38 PM

Quote:

Originally Posted by TedsBenz

My recent aquisition, an 84 300sd, had its AC converted to R134 according to the previous owner. He said he thought it had a small leak as it was not cooling well by the end of last summer. When I set the climate control for full blast AC I do not hear the customary click of the compressor kicking in, or see a change in idle. This what I'm use to hearing in my other vehicles. The air temp coming out the vents is whatever the temp is outside.

Do I walk into a MB repairshop and say, "make it work, again!"????

I need AC. but she is 24 years old...I don't want the repair to exceed the value of the car.

BTW, the heater temp control works great as do the blower speed/auto controls. The pods are stuck so that I get great defrosters....and some air out the side vents.

Any info would be appreciated.

1984 MB 300SD 383,280 miles...and just passed state inspection!

Ted,
When I had a '83 300SD, that I drove to 305K miles, I would take it to a quality indy AC shop in Richardson, Texas, that was typically 40% less than the MB dealer here in Dallas. A good independent shop that ONLY does AC is your best bet.

::matthew · #35 05-02-2009, 03:40 PM

Quote:

Originally Posted by Jerry Cohen

I'm not trying to scare people, just to make newbies cognizant of the real dangers of which I speak.

If your going to try to discredit me, why don't you prove me wrong? Instead of accusing me of trying to scare people in a vain attempt to to blur the facts.

Check for yourself what the real dangers are. Just don't look in the MSDS for R134a for safety precautions or check CDC statistics for known cases of poisoning from mustard gas, because they're not there.

There are many reasons illustrated here and on other threads why DIY on A/C systems might not be a good idea for people without the proper tools or knowledge, but risk of creating mustard gas ain't one of them.

Matt L · #36 05-02-2009, 04:24 PM

Quote:

Originally Posted by 2.5Turbo

I really like how the EPA says venting 134a is illegal while every "canned air" computer duster is full of the same stuff...

Go look at boat horns. Or inhalers, they're going R134a too. Or go to a hobby shop and ask about something to power your air brush. Yep, 134a there too, although it doesn't work all that well for the purpose.

Yes it is pretty silly, but consider how much refrigerant you let out in a year with these legal activities, and compare to how much an AC shop would lose in a year if they didn't recover.

showme · #37 05-02-2009, 05:14 PM

I may have missed something in there, but when we bought the wife's 81 300D 2 years ago, I had problems with the ac putting out cold air. Ours has an auto system, not manual control. I believe it was on this site that I got hold of a good explanation of the shrader valve that controls the ac\heat temp control. I bought the repair kit through ******** az (not the whole replacement part, which was over $100) for about $35. Took the 10 minutes to replace it, which consisted of unhooking the electric plug, pulling a few screws, pulling the small "guts" part with the bad rubber diaphragm, stuck the new one in, screwed it, plugged it in and it's worked great ever since. I still have to add some refer juice each summer, but that's easy (and cheap). Like I said, maybe yours isn't an automatic, maybe it doesn't use this type of valve, or maybe something else is the problem, but it's one of those easy fixes that made me glad I owned such an easy to work on vehicle. my problem was solved for less than the cost of a decent dinner, and took less time than to eat the same. Hope it's as easy for you. God forbid that you would have to get scalped for something that's easy and cheap. Good luck!

techguy512 · #38 05-02-2009, 06:21 PM

Quote:

Originally Posted by showme

I got hold of a good explanation of the shrader valve that controls the ac\heat temp control. I bought the repair kit through ******** az (not the whole replacement part, which was over $100) for about $35. Took the 10 minutes to replace it, which consisted of unhooking the electric plug, pulling a few screws, pulling the small "guts" part with the bad rubber diaphragm, stuck the new one in, screwed it, plugged it in and it's worked great ever since.

I believe you're referring to the monovalve, which is part of the heating system and in the engine coolant circuit, rather than the refrigerant circuit.

The earlier references in the thread were to the schrader valves, which are located at the refrigerant charging ports on the high and low pressure sides of the refrigerant circuit.

Jerry Cohen · #39 05-02-2009, 07:38 PM

Quote:

Originally Posted by ::matthew

Check for yourself what the real dangers are. Just don't look in the MSDS for R134a for safety precautions or check CDC statistics for known cases of poisoning from mustard gas, because they're not there.

There are many reasons illustrated here and on other threads why DIY on A/C systems might not be a good idea for people without the proper tools or knowledge, but risk of creating mustard gas ain't one of them.

I don't know what your qualifications are to make such statements, but coming from someone who first insisted that there aren't many open flames under the hood of a MB diesel, I doubt you know what are talking about.

Unless you are a chemist, stop trying to denigrate my comments.

::matthew · #40 05-02-2009, 09:54 PM

Quote:

Originally Posted by Jerry Cohen

I don't know what your qualifications are to make such statements, but coming from someone who first insisted that there aren't many open flames under the hood of a MB diesel, I doubt you know what are talking about.

Unless you are a chemist, stop trying to denigrate my comments.

I guess only I have one of the newer models without a pilot light....

Lycoming-8 · #41 05-03-2009, 12:42 AM

It is likely that most of these supposed MB diesels running around are in fact Doble Steamers in disguise. The dealers just slapped a funky grille and three pointed star on 'em to fake out the populace!!!!!!!

Simpler=Better · #42 05-03-2009, 12:56 AM

Competition paintballers use compressed N2. It's pretty cheap...sub $20 a fill

2.5Turbo · #43 05-03-2009, 03:33 AM

Quote:

Originally Posted by Matt L

Or inhalers, they're going R134a too.

That's true...and up until 2008, some were still using R12!

C Sean Watts · #44 05-03-2009, 05:20 PM

Quote:

Originally Posted by TedsBenz

My recent aquisition, an 84 300sd, had its AC converted to R134 according to the previous owner. He said he thought it had a small leak as it was not cooling well by the end of last summer. When I set the climate control for full blast AC I do not hear the customary click of the compressor kicking in, or see a change in idle. This what I'm use to hearing in my other vehicles. The air temp coming out the vents is whatever the temp is outside.

Do I walk into a MB repairshop and say, "make it work, again!"????

I need AC. but she is 24 years old...I don't want the repair to exceed the value of the car.

BTW, the heater temp control works great as do the blower speed/auto controls. The pods are stuck so that I get great defrosters....and some air out the side vents.

Any info would be appreciated.

1984 MB 300SD 383,280 miles...and just passed state inspection!

Ted, The truth is any 123 converted to R134a is not going to cool very well even if all other parts of the A/C system are new. The first thing is troubleshoot and find out where the deficiencies are, then correct those. Some A/C repairs turn out to be cheap, some do not.

There are many of us on this forum who do A/C work full time, some part time and some only 609 certified to do ONLY our own work. Personally, if I plan on keeping a car, using it as a daily driver I avoid "home brew" types of seat of the pants repairs. Going by the Bentley manual or FSM will not steer you wrong, ESPECIALLY when it comes to A/C work.

If you see 3-4 posts giving the same general answer, and they come from folks who have been around a while, they are generally the correct answer. Short cuts, guesses and skips in procedures are a sure way to ensure the A/C repair WILL cost $$$.

That being said...

NEVER
Mix the two types of refrigerants (R12 and R134a) the results are a toxic gas, so is the result when R12 is burned (don't use them around open flame.)

Mix or allow cross contamination of the lubricant oils UNLESS they are clearly labeled as compatible with the other.

Use substitutes like (this is not a complete list) Freeze 12, OZ-12, HC-12a, AutoFrost or McCool. These contain flammable mixtures and are illegal for use in cars, not because the government wants your money but their use(s) have resulted in fatalities.

Tamper or bypass safety systems in the car's system or service equipment.

DO
Get a good reference and read up on it. You will be more knowledgeable about it, THAT will save you money.

CANDIDE · #45 05-03-2009, 08:32 PM

Quote:

Originally Posted by ah-kay

There is what I do to fix my A/C without costing an arm and a leg. Some members here shout at me for using compress air and not nitrogen, but where do I find nitrogen in my garage?

1) You need to make sure there is no leak in the system. I use compress air to pressurize the system and make sure it holds. I then spray soapy water at joints ( reachable one ) to make sure there is no leak. If it leaks under the dash then you are out of luck. It is not worth fixing as it is expensive to do anything under the dash.
2) Assuming there is no leak. If you have a vacuum pump then evac it down real well. If you don't then do step 3a.
3) Then just charge it with R134a.
3a) When you are charging the system from the low side, release the air from the high side valve. Most air would be expelled in this manner.
4) The system would be pressured by now and the switch at the receiver/dryer should close. If it is not close then you need to jumper it to turn the compressor on.
5) 2 to 2 1/2 can of R134a should be enough for most cars.
6) You should have cold air if there is nothing wrong with the compressor or other components.

BTW: I always replace the receiver/dryer if I open the system. Also you may need to charge it with ester oil if you are converting the system from R12 to R134a for the 1st time.

Good luck.

Thanks for your contribution.
Does holding a vacuum on an ac system indicate no leaks? Or, must ac system under be tested under pressure?