Duracool Dash AC

kstockwell

kstockwell

Member
May 24, 2016
376
2
18
Hi All

My dash AC worked when i got it (topped off by the PO in 2017). It was converted to 134 years ago. I was tired of sweating everywhere we went (OK,
we're in VT not everywhere) so I paid to have it leak checked. HUGE leak in the condenser. So, I ordered a exact condenser, and the dryer and i
managed to twist the hose that went to the dryer (I expected a different part to spin), put it all together, borrowed a vacuum pump, got the whole
pressure manifold things, pumped it down and it held!

Then I filled it with duracool i ordered. I can't remember how many cans- somone said put in X cans to the GMC motorhome. It was the end of the
year, it worked and we were happy.

This year we only took one trip and I noticed that the AC blows cold but cycles, cold for 30 seconds, off for ~30 seconds. So I thought I should add
some more refrigerant.

I did, and am at the top end of the duracool dial that came with the kit (I didn't put the whole manifold on). At the top end of the "green" zone it
still cycles. It was certainly good enough; kept us cool but I'd like to have the right amount. Do i go by the duracool gauge? what pressure should
I have? Could I have put too much oil or something else in it?

The yellow zone ALERT starts at 45 (pounds?) Filled is 25-45. I am at 45 and cycling.

thank you
kelly
--
1978 Kingsley
Putney VT
 
Kelly, Here's an exerpt from Emery's excellent article: "Duracool in your
GMC" (aka, "The GMC Motorhome A/C Refrigerant Bible")

============================
. To install the Duracool attach the can hose to either your gauge set or
directly to the low either your gauge set or directly to the low pressure
side fitting (the one without the clutch pressure cut off switch)
. Put in one 6 oz. can. Point the fitting of the can down when filling.
. Then start the engine and turn on the air conditioner to high or Max.
. Put in another can Put in another can.
. If you are using gauges, have someone hold the gas pedal to 1500 rpm the
gas pedal to 1500 rpm.
. Start putting in the 3rd can until you have approx. 20 psi on the gauge.
If you are not using gauges put in the 3rd can and then
bleed off little until you feel you have cold enough air coming from your
outlets. About 40 deg below outside temperature.
. If you have too much of a charge it will not be as cold.
. If you have less charge it will be colder but in humid areas you could get
ice forming on the humid areas you could get ice forming on the evaporator
fins which will block air from blowing into your GMC.
====================

You likely have too much coolant in your system.

bdub

-----Original Message-----
From: On Behalf Of kelly stockwell via Gmclist
Sent: Sunday, September 13, 2020 8:32 AM
Subject: [GMCnet] Duracool Dash AC

Hi All

My dash AC worked when i got it (topped off by the PO in 2017). It was
converted to 134 years ago. I was tired of sweating everywhere we went (OK,
we're in VT not everywhere) so I paid to have it leak checked. HUGE leak in
the condenser. So, I ordered a exact condenser, and the dryer and i
managed to twist the hose that went to the dryer (I expected a different
part to spin), put it all together, borrowed a vacuum pump, got the whole
pressure manifold things, pumped it down and it held!

Then I filled it with duracool i ordered. I can't remember how many cans-
somone said put in X cans to the GMC motorhome. It was the end of the
year, it worked and we were happy.

This year we only took one trip and I noticed that the AC blows cold but
cycles, cold for 30 seconds, off for ~30 seconds. So I thought I should add
some more refrigerant.

I did, and am at the top end of the duracool dial that came with the kit (I
didn't put the whole manifold on). At the top end of the "green" zone it
still cycles. It was certainly good enough; kept us cool but I'd like to
have the right amount. Do i go by the duracool gauge? what pressure should
I have? Could I have put too much oil or something else in it?

The yellow zone ALERT starts at 45 (pounds?) Filled is 25-45. I am at 45
and cycling.
 
Kelly,

My experience with Duracool is less than others here, but it may be that you have an over-charged system. If you hook up the high side and get a
small bucket of ice, you may be able to put some back in the can. (Yes, I have done this.) Emery suggests a low side pressure of 15~20 at 1500 (fast
idle) and Emery does know what is going on.

I just wished that the sight glass in the drier was still worth checking. I find it to be of marginal value with either 134 or HC-12a.

Matt

> Hi All
>
> My dash AC worked when i got it (topped off by the PO in 2017). It was converted to 134 years ago. I was tired of sweating everywhere we went
> (OK, we're in VT not everywhere) so I paid to have it leak checked. HUGE leak in the condenser. So, I ordered a exact condenser, and the dryer and
> i managed to twist the hose that went to the dryer (I expected a different part to spin), put it all together, borrowed a vacuum pump, got the whole
> pressure manifold things, pumped it down and it held!
>
> Then I filled it with duracool i ordered. I can't remember how many cans- somone said put in X cans to the GMC motorhome. It was the end of the
> year, it worked and we were happy.
>
> This year we only took one trip and I noticed that the AC blows cold but cycles, cold for 30 seconds, off for ~30 seconds. So I thought I should
> add some more refrigerant.
>
> I did, and am at the top end of the duracool dial that came with the kit (I didn't put the whole manifold on). At the top end of the "green" zone
> it still cycles. It was certainly good enough; kept us cool but I'd like to have the right amount. Do i go by the duracool gauge? what pressure
> should I have? Could I have put too much oil or something else in it?
>
> The yellow zone ALERT starts at 45 (pounds?) Filled is 25-45. I am at 45 and cycling.
>
> thank you
> kelly

--
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
 
Interesting I might be high! I added roughly 1/2 can and get the same result. Maybe i should hook up the whole man fold again.
I think there was action in the sight glass- but i wasn't sure what I was looking for.

thank you for the suggestion!

> Kelly,
>
> My experience with Duracool is less than others here, but it may be that you have an over-charged system. If you hook up the high side and get a
> small bucket of ice, you may be able to put some back in the can. (Yes, I have done this.) Emery suggests a low side pressure of 15~20 at 1500
> (fast idle) and Emery does know what is going on.
>
> I just wished that the sight glass in the drier was still worth checking. I find it to be of marginal value with either 134 or HC-12a.
>
> Matt
>

> > Hi All
> >
> > My dash AC worked when i got it (topped off by the PO in 2017). It was converted to 134 years ago. I was tired of sweating everywhere we
> > went (OK, we're in VT not everywhere) so I paid to have it leak checked. HUGE leak in the condenser. So, I ordered a exact condenser, and the
> > dryer and i managed to twist the hose that went to the dryer (I expected a different part to spin), put it all together, borrowed a vacuum pump,
> > got the whole pressure manifold things, pumped it down and it held!
> >
> > Then I filled it with duracool i ordered. I can't remember how many cans- somone said put in X cans to the GMC motorhome. It was the end of
> > the year, it worked and we were happy.
> >
> > This year we only took one trip and I noticed that the AC blows cold but cycles, cold for 30 seconds, off for ~30 seconds. So I thought I
> > should add some more refrigerant.
> >
> > I did, and am at the top end of the duracool dial that came with the kit (I didn't put the whole manifold on). At the top end of the "green"
> > zone it still cycles. It was certainly good enough; kept us cool but I'd like to have the right amount. Do i go by the duracool gauge? what
> > pressure should I have? Could I have put too much oil or something else in it?
> >
> > The yellow zone ALERT starts at 45 (pounds?) Filled is 25-45. I am at 45 and cycling.
> >
> > thank you
> > kelly

--
1978 Kingsley
Putney VT
 
thank you- i had forgotten, i referred to this when i did my work last year

Though he says if it's high it won't cool as much. My understanding is undercharged cycles the compressor- any idea what would cause the compressor
to cycle?
--
1978 Kingsley
Putney VT
 
I don't know. Evidently there's a balance there. Mine does that as well
but not near that quickly. It is an annoyance.

On Sun, Sep 13, 2020, 9:37 AM kelly stockwell via Gmclist <

> thank you- i had forgotten, i referred to this when i did my work last year
>
> Though he says if it's high it won't cool as much. My understanding is
> undercharged cycles the compressor- any idea what would cause the compressor
> to cycle?
>
>
 
It doesn't seem to be cooling, because it is blocked by frost. Shoot for 20
- 25 inches. It is a happy compromise. Pay attention to stuff like vaccuum
doors that open and close when they should, and vents that direct the
airflow where you feel maximum effect. That stuff is all 40 years old, and
needs some looking after from time to time.
Jim Hupy
Salem, Oregon

On Sun, Sep 13, 2020, 8:05 AM Billy Massey via Gmclist <

> I don't know. Evidently there's a balance there. Mine does that as well
> but not near that quickly. It is an annoyance.
>
>
> On Sun, Sep 13, 2020, 9:37 AM kelly stockwell via Gmclist <

>
> > thank you- i had forgotten, i referred to this when i did my work last
> year
> >
> > Though he says if it's high it won't cool as much. My understanding is
> > undercharged cycles the compressor- any idea what would cause the
> compressor
> > to cycle?
> >
> >
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
it does blow wicked cold when on- i will do this
thank you

> It doesn't seem to be cooling, because it is blocked by frost. Shoot for 20
> - 25 inches. It is a happy compromise. Pay attention to stuff like vaccuum
> doors that open and close when they should, and vents that direct the
> airflow where you feel maximum effect. That stuff is all 40 years old, and
> needs some looking after from time to time.
> Jim Hupy
> Salem, Oregon
>
> On Sun, Sep 13, 2020, 8:05 AM Billy Massey via Gmclist <

>
> > I don't know. Evidently there's a balance there. Mine does that as well
> > but not near that quickly. It is an annoyance.
> >
> >

> >
> >> thank you- i had forgotten, i referred to this when i did my work last
> > year
> >>
> >> Though he says if it's high it won't cool as much. My understanding is
> >> undercharged cycles the compressor- any idea what would cause the
> > compressor
> >> to cycle?
> >>
> >>
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> > http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
> >
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

--
1978 Kingsley
Putney VT
 
It isn’t necessarily cycling on the loss of charge pressure switch. It may be cycling on the low temperature control located in the evaporator air
behind the evap coil.
--
Roy Keen
Minden,NV
76 X Glenbrook
 
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