All,

Is there a way to build/connect the following items to an AC system
and have it evacuate all of the refrigerant.

1. Manifold gauge set
2. 2cfm 2-stage vacuum pump 110v
3. emty propane tank.

My understangin is that the commercial units costing $4,000
essentially are built fromthe same components.
I have no plans to reuse the old 134a. All I want to do is
depressurize the system so that I can replace a bad compressor.

BoBo wrote:
If the compressor's shot, there probably isn't that much refrigerant
left in the system to worry about.

On Wed, 16 May 2007 20:19:11 -0400, BoBo <bobo (AT) nowhere (DOT) com> wrote:

Sounds like it would be cheaper (and easier) to purchase a compressor,
and take it to a certified shop to have it replaced and your system
vacuumed and recharged. I had a Ford done recently for $120.

It does take some expertize to do the job right/safely. Not knowing
what the gauges are 'telling' you can lead to a dangerous situation and
damage the ac system. None of it is rocket-surgery though and is easy
enough to learn.

As to evacuating the system: I'd suspect that was done already by the
compressor when it gave up. The gauges will tell you that. A vacuum
pump might be a good investment in the 'long run'

Those evacuating systems not only capture the refrigerant but also
clean/recycle it for reuse.

Dave S(Texas)

On Thu, 17 May 2007 18:49:13 -0400, "Steve W." <yahoo (AT) yahoo (DOT) com>
wrote:



The compressor didn't have a massive failure. Only the seals are
leaking. Nevertheless, I will blow out the system wth compressed air
before recharging, replace the orafice tube and accumulator.

On Thu, 17 May 2007 08:26:53 -0500, putt (AT) webtv (DOT) net wrote:

I have the factory service manual for the truck that explains in
detail how to diagnose and repair the ac system. As long as I keep an
eye on the gauges and I don't open the high side while recharging,
it's pretty safe and starightforward procedure.

The manifold is in the process of being shipped so I don't know what
the pressures are. Assuming both high/low sides read zero, what is the
possibility of liquid refrigerant still remaining? If there is a leak,
will all of the liquid refrigerant boil off in a matter of a few
seconds once the atmosphere enters the system?

On Fri, 18 May 2007 06:58:40 -0400, BoBo <bobo (AT) nowhere (DOT) com> wrote:

The same as your gauges read, zero.

Depends on the size of the leak, but once you open the system (like
disconnecting line sets), the liquid will boil off almost instantly.

"BoBo" <bobo (AT) nowhere (DOT) com> wrote


As I suggested in my previous post, and in total agreement with Steve W.,
you may well need to flush the system even if you have not had a major
failure.

I just did my Reatta and upgraded it to R134a. It did not have a major
failure, just an R12 leak at the front seal. It was not even a big leak.

We did the job correctly. We replaced the compressor AFTER removing
the expansion device and filter/drier and flushing. It was full of black
corruption.

There is a right way and a wrong way. You may get away with doing a
halfway job....for a while.

Even doing it the right way should not cost $1100.

The whole system must be flushed. This procedure can not be
side-stepped. De-natured alcohol pushed through the lines under
pressure will do the job. Compressors are not a piece you want to
replace often. The orifice tube must be replaced and the accumulator
should also be replaced. Follow the procedures for adding oil into the
system. Check every connection for signs of leaking. While the system
is 'down', I'd replace the O-rings at all connections. Doing the job
right will be rewarded with a trouble-free AC system for years to come.

Dave S(Texas)