B
Baz
Hi all,
About a month ago I had the evaporator replaced in my '96 850 (non climate
control), by a Volvo dealer (ouch!) in Sydney Australia. It was a big job
and I felt they would be able to do it with a lot less trouble than I could.
And it was done quickly and professionally.
The old evaporator was definitely leaking, it would lose 10" Hg vacuum over
45 minutes. I kept the old evaporator and checked it under UV light as I
had dye in the sytem. There appeared to be many minute spots. Sounds
typical. It lasted 9 years.
I hadn't noticed anything unusual until last Friday, which was hot, 35deg
C, when I noticed the compressor started cutting in and out at less than 5
second intervals, when I pulled into my garage. The a/c vent temperature
seemed to be warmer than usual, so I was suspicious and taking note.
My first thoughts were that it had a leak and was low on refrigerant, and I
rang the dealer and have it booked in to be looked at next week.
Saturday morning was cooler, 26deg C. In my garage, (at 1500 rpm) I found
that with the internal fan on pos 4 (full) I could get the air temperature
down to just above 0 deg C, and the compressor didn't cut in and out
rapidly. However later in the day on a run when it got hot again, it
started "short cycling" again.
Today I bypassed the "superheat" switch on the compressor, and ran the a/c
in the garage again, ambient temperature around 25 deg C. The compressor
didn't cut out for some time, not until I closed the windows of the car.
The vent temperature dropped to 5 deg C. This seems normal. The low
pressure line and receiver/dryer were sweating profusely (and dripping on
the floor), but the pipe into the low pressure side of the compressor
actually iced up (thinly, I could scratch it off with my fingernail) to
within maybe 3mm of the compressor. The compressor body itself around the
inlet pipe was cold but not sweating. I don't know if this is normal, any
comments? The compressor cycled, but around once in 30 seconds.
When taken for a run with the superheat switch bypassed it behaved as
before, short cycling (around 5 seconds on and off). Vent temperature
around 10 deg C. Outside around 25 deg C.
I've reconnected the superheat switch as it didn't seem to be making any
difference.
It didn't behave like this before the evaporator was replaced, that I can
remember. The compressor cutting in and out isn't all that noticeable
unless I listen for it when I'm on the road.
I don't think this is correct and my feelings are that it's overcharged
rather than leaking. Does anyone have any comments?
Regards
Barry
About a month ago I had the evaporator replaced in my '96 850 (non climate
control), by a Volvo dealer (ouch!) in Sydney Australia. It was a big job
and I felt they would be able to do it with a lot less trouble than I could.
And it was done quickly and professionally.
The old evaporator was definitely leaking, it would lose 10" Hg vacuum over
45 minutes. I kept the old evaporator and checked it under UV light as I
had dye in the sytem. There appeared to be many minute spots. Sounds
typical. It lasted 9 years.
I hadn't noticed anything unusual until last Friday, which was hot, 35deg
C, when I noticed the compressor started cutting in and out at less than 5
second intervals, when I pulled into my garage. The a/c vent temperature
seemed to be warmer than usual, so I was suspicious and taking note.
My first thoughts were that it had a leak and was low on refrigerant, and I
rang the dealer and have it booked in to be looked at next week.
Saturday morning was cooler, 26deg C. In my garage, (at 1500 rpm) I found
that with the internal fan on pos 4 (full) I could get the air temperature
down to just above 0 deg C, and the compressor didn't cut in and out
rapidly. However later in the day on a run when it got hot again, it
started "short cycling" again.
Today I bypassed the "superheat" switch on the compressor, and ran the a/c
in the garage again, ambient temperature around 25 deg C. The compressor
didn't cut out for some time, not until I closed the windows of the car.
The vent temperature dropped to 5 deg C. This seems normal. The low
pressure line and receiver/dryer were sweating profusely (and dripping on
the floor), but the pipe into the low pressure side of the compressor
actually iced up (thinly, I could scratch it off with my fingernail) to
within maybe 3mm of the compressor. The compressor body itself around the
inlet pipe was cold but not sweating. I don't know if this is normal, any
comments? The compressor cycled, but around once in 30 seconds.
When taken for a run with the superheat switch bypassed it behaved as
before, short cycling (around 5 seconds on and off). Vent temperature
around 10 deg C. Outside around 25 deg C.
I've reconnected the superheat switch as it didn't seem to be making any
difference.
It didn't behave like this before the evaporator was replaced, that I can
remember. The compressor cutting in and out isn't all that noticeable
unless I listen for it when I'm on the road.
I don't think this is correct and my feelings are that it's overcharged
rather than leaking. Does anyone have any comments?
Regards
Barry
