front air conditioner troubleshooting

[Dorn Hetzel]

I am trying to diagnose a non-functional front AC (the engine driven one).

The system does not seem to have any significant leaks, as it will
hold a vacuum when pumped down.

A local shop helped me add the conversion connectors so we could
connect the system to their diagnostic equipment.

After holding a vacuum on the system for 30 minutes, we added some
refrigerant and started up.

There is a very small amount of cooling generated, but high-side
pressure builds very high, up to 500 lbs, which leads me to guess that
there is a blockage somewhere on the high side before the expansion
valve.

So, we pumped the refrigerant back out and I took the bird home and I
am setting up to pump air through the various lines to see if and
where the flow is restricted.

I am trying to remove the high side line at the compressor, and there
are some clamps on hose, which I have loosened and pulled back, but
the hose still won't come off the barb fitting.

I am wondering if I am going to have to sacrifice that last couple
inches of the hose and cut it off, or if there is a better way?

Here is a link to a picture of the compressor and hose and with
retracted clamps. Any suggestions?

http://www.hetzel.org/2009-05-30-01-bb-02.jpg

Regards,

Dorn Hetzel
77FC35
Hogansville, GA

[Curt Sprenger]

Cut the hose, remove the hose fitting, install a nipple and pipe coupler, install the hose fitting.

Curt Sprenger

1987 PT38 8V92 "MacAttack Racing"

Anaheim Hills, CA
Read all about Southwest Bluebirds and Friends (SWBB) at http://www.SOUTHWEST-BLUEBIRDS.ORG ...Then Join us.

"Host of the Annual Bluebird Quartzsite Rally"

On Sat, May 30, 2009 at 1:16 PM, Dorn Hetzel <"dorn@hetzel.org"> wrote:

I am trying to diagnose a non-functional front AC (the engine driven one).



The system does not seem to have any significant leaks, as it will

hold a vacuum when pumped down.



A local shop helped me add the conversion connectors so we could

connect the system to their diagnostic equipment.



After holding a vacuum on the system for 30 minutes, we added some

refrigerant and started up.



There is a very small amount of cooling generated, but high-side

pressure builds very high, up to 500 lbs, which leads me to guess that

there is a blockage somewhere on the high side before the expansion

valve.



So, we pumped the refrigerant back out and I took the bird home and I

am setting up to pump air through the various lines to see if and

where the flow is restricted.



I am trying to remove the high side line at the compressor, and there

are some clamps on hose, which I have loosened and pulled back, but

the hose still won't come off the barb fitting.



I am wondering if I am going to have to sacrifice that last couple

inches of the hose and cut it off, or if there is a better way?



Here is a link to a picture of the compressor and hose and with

retracted clamps. Any suggestions?



http://www.hetzel.org/2009-05-30-01-bb-02.jpg



Regards,



Dorn Hetzel

77FC35

Hogansville, GA

[ronmarabito2002]

Take some channel lock pliers and try to rotate the hose on the fitting. If
that doesn't turn it loose and you have sufiecient hose, then cut it off and
move along.

R.E. (Ron) Marabito, Dallas, TX 92WB40

--- In WanderlodgeForum@yahoogroups.com, Dorn Hetzel wrote:
>
> I am trying to diagnose a non-functional front AC (the engine driven one).
>
> The system does not seem to have any significant leaks, as it will
> hold a vacuum when pumped down.
>
> A local shop helped me add the conversion connectors so we could
> connect the system to their diagnostic equipment.
>
> After holding a vacuum on the system for 30 minutes, we added some
> refrigerant and started up.
>
> There is a very small amount of cooling generated, but high-side
> pressure builds very high, up to 500 lbs, which leads me to guess that
> there is a blockage somewhere on the high side before the expansion
> valve.
>
> So, we pumped the refrigerant back out and I took the bird home and I
> am setting up to pump air through the various lines to see if and
> where the flow is restricted.
>
> I am trying to remove the high side line at the compressor, and there
> are some clamps on hose, which I have loosened and pulled back, but
> the hose still won't come off the barb fitting.
>
> I am wondering if I am going to have to sacrifice that last couple
> inches of the hose and cut it off, or if there is a better way?
>
> Here is a link to a picture of the compressor and hose and with
> retracted clamps. Any suggestions?
>
> http://www.hetzel.org/2009-05-30-01-bb-02.jpg
>
> Regards,
>
> Dorn Hetzel
> 77FC35
> Hogansville, GA
>

[timvasqz]

If you can cut a 1/2 inch section off of the end of the hose while it is on the
barb, sometimes you can push the hose on farther and free it up. prob is if it
is too brittle to come off the barb you may have found the restriction to be a
compromised old hose. If the motor run ac project gets too expensive, a large
inverter hooked to the foremost 110 ac may just be the ticket.

Greg of Tim&Greg
94ptca

--- In WanderlodgeForum@yahoogroups.com, Dorn Hetzel wrote:
>
> I am trying to diagnose a non-functional front AC (the engine driven one).
>
> The system does not seem to have any significant leaks, as it will
> hold a vacuum when pumped down.
>
> A local shop helped me add the conversion connectors so we could
> connect the system to their diagnostic equipment.
>
> After holding a vacuum on the system for 30 minutes, we added some
> refrigerant and started up.
>
> There is a very small amount of cooling generated, but high-side
> pressure builds very high, up to 500 lbs, which leads me to guess that
> there is a blockage somewhere on the high side before the expansion
> valve.
>
> So, we pumped the refrigerant back out and I took the bird home and I
> am setting up to pump air through the various lines to see if and
> where the flow is restricted.
>
> I am trying to remove the high side line at the compressor, and there
> are some clamps on hose, which I have loosened and pulled back, but
> the hose still won't come off the barb fitting.
>
> I am wondering if I am going to have to sacrifice that last couple
> inches of the hose and cut it off, or if there is a better way?
>
> Here is a link to a picture of the compressor and hose and with
> retracted clamps. Any suggestions?
>
> http://www.hetzel.org/2009-05-30-01-bb-02.jpg
>
> Regards,
>
> Dorn Hetzel
> 77FC35
> Hogansville, GA
>