Another A/C thread, my apologies! - Page 2 - PeachParts Mercedes-Benz Forum

markho · #16 06-24-2010, 12:47 PM

Quote:

Originally Posted by LarryBible

See post #10 above.

larry your dealing with a moron in 90 heat. How do I know its flooded?

markho · #17 07-02-2010, 10:21 AM

okay gents, I replaced the monovalve (bosch) and tried to also fill the system with more 134a, which would not enter because I guess its filled and pressured to capacity. The air conditioner blows warm/ambient air. My car's temp is running at normal temp around 80*. what's the next thing I must look at? thanks.

leathermang · #18 07-02-2010, 10:59 AM

Ok, You will need to tell us exactly what you did when you tried to install some refrigerant ... because the chances are 98 percent that you had something missing in the procedure... but tell us everything the first time... where did you try to install it, was the car running, how were the AC knobs set, the fan blower, the windows up or down, a thermometer in the vent ?, did you use warm water to set the can in , did you use standard hoses and AC manifold ? Then we may can help you.. but doing a half way job on a previous suggestion and then trying to move on... not logical and not likely to get you cooled off anytime soon...

I have an apt I have to leave for... will check back this afternoon...sorry...

markho · #19 07-02-2010, 11:30 AM

Quote:

Originally Posted by leathermang

Ok, You will need to tell us exactly what you did when you tried to install some refrigerant ... because the chances are 98 percent that you had something missing in the procedure... but tell us everything the first time... where did you try to install it, was the car running, how were the AC knobs set, the fan blower, the windows up or down, a thermometer in the vent ?, did you use warm water to set the can in , did you use standard hoses and AC manifold ? Then we may can help you.. but doing a half way job on a previous suggestion and then trying to move on... not logical and not likely to get you cooled off anytime soon...

I have an apt I have to leave for... will check back this afternoon...sorry...

I tried installing the 134a on the main hose near the front of the car with the little blue? knob. The car was running at full operating temp. Knobs were set to a/c with all vents blowing at high. windows were up, no thermometer at the vent, and I did not use warm water to set the (refrigerant?) can in. Thanks.

vstech · #20 07-02-2010, 11:42 AM

ok, for an a/c system to work properly it must have the correct volume of refrigerant in it, and the coils have to transfer heat in and out of the refrigerant. the compressor has to compress (thus heating) the gas, and the condenser removes heat, the expansion valve reduces the pressure, causing cooling, and the evaporator transfers heat into it. the cycle continues.
to help we need to know how much refrigerant is in the system. you don't know. best guess is with readings on both the high pressure port, the low pressure port, the temp out the vents will help, but the temp on the return line is better. also the outside ambient temp, and the temps of the lines going into and exiting the condenser.
at the very least we need the low pressure reading and a few temps...
can you get that?

markho · #21 07-02-2010, 12:08 PM

Quote:

Originally Posted by vstech

ok, for an a/c system to work properly it must have the correct volume of refrigerant in it, and the coils have to transfer heat in and out of the refrigerant. the compressor has to compress (thus heating) the gas, and the condenser removes heat, the expansion valve reduces the pressure, causing cooling, and the evaporator transfers heat into it. the cycle continues.
to help we need to know how much refrigerant is in the system. you don't know. best guess is with readings on both the high pressure port, the low pressure port, the temp out the vents will help, but the temp on the return line is better. also the outside ambient temp, and the temps of the lines going into and exiting the condenser.
at the very least we need the low pressure reading and a few temps...
can you get that?

well, i'm sure i can but i don't think i have the tool to get the pressure readings, and how would i get the temp on the return/condenser lines?

Laser temp?

vstech · #22 07-02-2010, 12:15 PM

a laser temp will give you approximate readings, and that'll be fine for starters.
you would need a set of gauges to read the pressures, autozone has a nice set with 134 fittings for around 80.00

leathermang · #23 07-02-2010, 05:34 PM

Quote:

Originally Posted by markho

I tried installing the 134a on the main hose near the front of the car with the little blue? knob. The car was running at full operating temp. Knobs were set to a/c with all vents blowing at high. windows were up, no thermometer at the vent, and I did not use warm water to set the (refrigerant?) can in. Thanks.

Your windows should have been down.
why did you not use warm water when it appeared that it was not entering the system ? That is SOP.
How do we know that you were trying to install it in the LOW side...
as compared to the high side... which would pretty much cause the situation you encountered...
Pictures are needed.
Have you spent any time reading other AC threads on this forum ?

markho · #24 07-02-2010, 07:22 PM

Quote:

Originally Posted by leathermang

Have you spent any time reading other AC threads on this forum ?

i have, but only on the monovalve since that was the first recommendation.
So, after I installed the monovalve, what should have I done and in what order? I will report back with pics, but in short I used the valve with the blue cap in the front of the car almost above the radiator. I have no clue if that's the low or the high.

Sulawesi · #25 07-02-2010, 07:56 PM

Not intending to hijack...everyone says there are numerous A/C threads. Fine, but I cannot find one that begins at the start, the car is new to me, and the A/C does not work...where to start? Links?

leathermang · #26 07-02-2010, 08:35 PM

Quote:

Originally Posted by markho

I have no clue if that's the low or the high.

I want to WARN you right now that you do not have enough knowledge to be safely working on your AC system.

I almost blew up a can of R12 IN MY FACE by not knowing which was the high and low side in the early 1970's... I was in my early 20's..... I did not even have goggles on ... I was lucky... when I felt of the can it was hot and I realized it was not supposed to be hot... it should be noticeably cool when it is discharging.. You need to stop putting your hands on your AC system until you have done more research.

markho · #27 07-02-2010, 09:35 PM

Quote:

Originally Posted by leathermang

I want to WARN you right now that you do not have enough knowledge to be safely working on your AC system.

I almost blew up a can of R12 IN MY FACE by not knowing which was the high and low side in the early 1970's... I was in my early 20's..... I did not even have goggles on ... I was lucky... when I felt of the can it was hot and I realized it was not supposed to be hot... it should be noticeably cool when it is discharging.. You need to stop putting your hands on your AC system until you have done more research.

i agree and understand the risks involved, however we need to back up on the story of this thread-I had already charged the system with r134a in April and it worked fine up until about the end of May. Autozone actually pointed out the fitting to install the can of r134a, and it did turn cold while it charged up the system. It worked fine and all was good, until it stopped blowing cold.

I won't go any further than I believe I can fix, I know that all of this stuff is under pressure.thanks...