QuestionI've got an 84 K-10 Suburban... the a/c has been converted to r-134a and has worked great. everything has been replaced since the conversion including the compressor, condensor, pressure cycle switch, filter, etc. System seems to hold charge just fine (according to pressure gauge) but compressor cycles quickly. I am not currently getting any cooling out of the system. I have cleaned all the lines and nothing I can find seems to be blocked.
When I shut the truck down, I hear a loud hissing noise as if excess pressure is escaping under the dash. I cannot find the source of the sound, but was wondering if this could be a leak that's being "opened" under pressure and "closing" as refrigerant escapes.
Any ideas? Truck has front and rear a/c and has worked exceptionally in the past. My family's tired of riding with me in the heat.
Thanks-
Wade
AnswerSounds like you have either a restriction in the ORIFICE TUBE and or the pressure cycling switch is defective. Try using your old pressure cycling switch and see what happens.
What are your HIGH and LOW pressures when the compressor is running ?.
The HISSSING that you hear is caused by the ORIFICE TUBE and or excessive high side pressure..
