AC Hissing
Thread Starter
Racer
Joined: Nov 2006
Posts: 264
Likes: 8
From: Centre, AL
AC Hissing
Just rebuilt my AC system. New compressor, new accumulator, orifice tube. Flushed out some of the pipes as well as the condenser. Filled with about 9.5 ounces of PAG 150...4 in the compressor, 5 or so in the accumulator...spilled a bit, so around 9 - 9.5
The condenser as well as some of the pipes are clean, so the oil should go there later on. Pulled and kept a vacuum for over 24 hours, so no leaks. Filled with about 1.6 lbs of R134A..more or less, a bit difficult to measure. At 30% humidity, 90F, 24 low and 230 or so high. 40 at the vent, so cools great.
Basically everything works, but now the system hisses. I know about the hissing when you switch the engine off, gas going from high to low side, but now hisses all the time, and this is a different hiss. Not horribly, but definitely hear it behind the dash. Did not touch the dash, and there was no hissing there before. Checked the little t hose behind the manifold, and that looks good. Could be a fan. Had problems with noisy fans once when the AC pressure was low, could not understand why the fan would only make a noise when the AC is on, and the noise (different noise) went away once the AC was fully charged. Any ideas?
The condenser as well as some of the pipes are clean, so the oil should go there later on. Pulled and kept a vacuum for over 24 hours, so no leaks. Filled with about 1.6 lbs of R134A..more or less, a bit difficult to measure. At 30% humidity, 90F, 24 low and 230 or so high. 40 at the vent, so cools great.
Basically everything works, but now the system hisses. I know about the hissing when you switch the engine off, gas going from high to low side, but now hisses all the time, and this is a different hiss. Not horribly, but definitely hear it behind the dash. Did not touch the dash, and there was no hissing there before. Checked the little t hose behind the manifold, and that looks good. Could be a fan. Had problems with noisy fans once when the AC pressure was low, could not understand why the fan would only make a noise when the AC is on, and the noise (different noise) went away once the AC was fully charged. Any ideas?
Last edited by waterzap; Oct 9, 2007 at 11:26 PM.
