ACTION NAPA AUTO Parts - (Page 29)
By Paul Weissler, MACS Senior Technical Correspondent
"
There is more
than one way to
find a leak.
It's a gusher, but I can't find it." Boy have
we heard that line a lot over the years; the
big leak that causes the system to dump a
full charge in a few days, maybe less. One
of the problems is that when a leak is that
large, a technician seems to think there should be
a geyser-like spray he can see. Instead, he finds
nothing obvious, even after a couple of system recharges with a double dose of dye.
One of the issues we've found is that a technician doesn't actually put in a full charge; maybe a
pound or so on an old system, even less on a newer
car. But there's enough for the compressor to engage and the system to put out some amount of
cold air in the moderate temperatures of the typical
shop. If the system then loses half that charge in
a few days, it's down enough for the low-pressure
switch or refrigerant pressure sensor to kick in and
keep the compressor from engaging.
That's why we recommend recovery and recharge with a machine that meets SAE J2788.
You'll know how much you pulled out and put in.
With low-cost R-134a, that's still a viable strategy.
But with very expensive R-1234yf on the horizon,
there will be a premium on leak detection without
the possibility of blowing a pound or more of a
refrigerant that presently is running about $100 or
more a pound at the shop level. And with environmental groups pushing for the earliest possible
phase out of R-134a, the leak detection issue isn't
going to get easier.
Trace dye is not going away, for a number of
reasons. Most important, it does detect leaks that
we don't find with other methods including electronic detectors. It's not that there's anything
wrong with the detectors. They're better than ever.
But with today's power train compartments, and
the convoluted routing of A/C lines, we can't get
an electronic detector probe easily into a good position to find some leaks. But we often can aim a
light into the area and see a dye trace.
And down the line there's a forthcoming factor:
carbon dioxide air conditioning systems, to which
leading German car manufacturers have committed
themselves (Mercedes-Benz, BMW, VW/Audi and
Porsche). They have made it clear that at this point
trace dye is their preferred method of leak detection. We can't tell you much about carbon dioxide
A/C at this point, because the prototype systems
are about a year off, but the commitment is pretty
firm. Wasn't that also true back in 2010? Yes,
but then there was the "go-along" attitude toward
R-1234yf, until Mercedes-Benz led the objections
Spring 2015 * ACTION/NAPA
29
ACTION NAPA AUTO Parts
Table of Contents for the Digital Edition of ACTION NAPA AUTO Parts
Engine Cooling Systems: Electric cooling fan operating strategies
The next 609 is here
Computer controls for air conditioning compressors
Getting legal
Mechanical fan clutch diagnosis
Properly mixing coolant
Selling the right things
Ford 6.4L Powerstroke
A big bad leak, but where
Recovering the entire charge
Blower Motor Mystery
Case Study: 1999 Jetta A/C Fuse
System Charge Determination
ACTION NAPA AUTO Parts - Cover1
ACTION NAPA AUTO Parts - Cover2
ACTION NAPA AUTO Parts - 3
ACTION NAPA AUTO Parts - Engine Cooling Systems: Electric cooling fan operating strategies
ACTION NAPA AUTO Parts - 5
ACTION NAPA AUTO Parts - 6
ACTION NAPA AUTO Parts - 7
ACTION NAPA AUTO Parts - The next 609 is here
ACTION NAPA AUTO Parts - 9
ACTION NAPA AUTO Parts - 10
ACTION NAPA AUTO Parts - 11
ACTION NAPA AUTO Parts - Computer controls for air conditioning compressors
ACTION NAPA AUTO Parts - 13
ACTION NAPA AUTO Parts - 14
ACTION NAPA AUTO Parts - 15
ACTION NAPA AUTO Parts - Getting legal
ACTION NAPA AUTO Parts - 17
ACTION NAPA AUTO Parts - Mechanical fan clutch diagnosis
ACTION NAPA AUTO Parts - Properly mixing coolant
ACTION NAPA AUTO Parts - 20
ACTION NAPA AUTO Parts - 21
ACTION NAPA AUTO Parts - Selling the right things
ACTION NAPA AUTO Parts - 23
ACTION NAPA AUTO Parts - 24
ACTION NAPA AUTO Parts - 25
ACTION NAPA AUTO Parts - Ford 6.4L Powerstroke
ACTION NAPA AUTO Parts - 27
ACTION NAPA AUTO Parts - A big bad leak, but where
ACTION NAPA AUTO Parts - 29
ACTION NAPA AUTO Parts - 30
ACTION NAPA AUTO Parts - Recovering the entire charge
ACTION NAPA AUTO Parts - Blower Motor Mystery
ACTION NAPA AUTO Parts - 33
ACTION NAPA AUTO Parts - 34
ACTION NAPA AUTO Parts - Case Study: 1999 Jetta A/C Fuse
ACTION NAPA AUTO Parts - 36
ACTION NAPA AUTO Parts - System Charge Determination
ACTION NAPA AUTO Parts - 38
ACTION NAPA AUTO Parts - Cover3
ACTION NAPA AUTO Parts - Cover4
https://www.nxtbook.com/nxtbooks/macs/action_20170708
https://www.nxtbook.com/nxtbooks/macs/action_20176
https://www.nxtbook.com/nxtbooks/macs/action_201706
https://www.nxtbook.com/nxtbooks/macs/action_201705
https://www.nxtbook.com/nxtbooks/macs/action_201704
https://www.nxtbook.com/nxtbooks/macs/action_201703
https://www.nxtbook.com/nxtbooks/macs/action_20170102
https://www.nxtbook.com/nxtbooks/macs/action_20161112
https://www.nxtbook.com/nxtbooks/macs/action_20160910_v2
https://www.nxtbook.com/nxtbooks/macs/action_20160910
https://www.nxtbook.com/nxtbooks/macs/action_20160708
https://www.nxtbook.com/nxtbooks/macs/action_napa_2016spring
https://www.nxtbook.com/nxtbooks/macs/action_201606
https://www.nxtbook.com/nxtbooks/macs/action_201605
https://www.nxtbook.com/nxtbooks/macs/action_201604
https://www.nxtbook.com/nxtbooks/macs/action_201603
https://www.nxtbook.com/nxtbooks/macs/action_20160102
https://www.nxtbook.com/nxtbooks/macs/action_20151112
https://www.nxtbook.com/nxtbooks/macs/action_20150910
https://www.nxtbook.com/nxtbooks/macs/action_20150708
https://www.nxtbook.com/nxtbooks/macs/action_napa_2015spring
https://www.nxtbook.com/nxtbooks/macs/action_napa_2015spring_v2
https://www.nxtbook.com/nxtbooks/macs/action_201506
https://www.nxtbook.com/nxtbooks/macs/action_201505
https://www.nxtbook.com/nxtbooks/macs/action_201504
https://www.nxtbook.com/nxtbooks/macs/action_201503
https://www.nxtbook.com/nxtbooks/macs/action_20150102
https://www.nxtbook.com/nxtbooks/macs/action_20141112
https://www.nxtbook.com/nxtbooks/macs/action_201409
https://www.nxtbook.com/nxtbooks/macs/action_20140708
https://www.nxtbook.com/nxtbooks/macs/action_201406
https://www.nxtbook.com/nxtbooks/macs/action_201405
https://www.nxtbook.com/nxtbooks/macs/action_201404
https://www.nxtbook.com/nxtbooks/macs/action_201403
https://www.nxtbook.com/nxtbooks/macs/action_20140102
https://www.nxtbook.com/nxtbooks/macs/action_20131112
https://www.nxtbook.com/nxtbooks/macs/action_20130910
https://www.nxtbook.com/nxtbooks/macs/action_201307
https://www.nxtbook.com/nxtbooks/macs/action_201306
https://www.nxtbook.com/nxtbooks/macs/action_201305
https://www.nxtbook.com/nxtbooks/macs/action_201304
https://www.nxtbook.com/nxtbooks/macs/action_201303
https://www.nxtbook.com/nxtbooks/macs/action_20130102
https://www.nxtbook.com/nxtbooks/macs/action_20121112
https://www.nxtbook.com/nxtbooks/macs/action_20120910
https://www.nxtbook.com/nxtbooks/macs/action_201207
https://www.nxtbook.com/nxtbooks/macs/action_201206
https://www.nxtbook.com/nxtbooks/macs/action_201205
https://www.nxtbook.com/nxtbooks/macs/action_20120304
https://www.nxtbook.com/nxtbooks/macs/action_20120102
https://www.nxtbook.com/nxtbooks/macs/action_20111112
https://www.nxtbook.com/nxtbooks/macs/action_20110910
https://www.nxtbookmedia.com