Ok both my rooftops are not working. Dometic Duro Therms.Took covers off and installed peircing service valves. Both had no freon. Both had pin holes in capillary tube in same place apparently rubbing issue. Cut sheet metal to access. Put a drop of braze on one and cut one out and sleeved with a peice of 1/4 inch tube and brazed. Pulled a vacuum on both and filled both with 24.5 oz of r22.Wasn't very warm but shot the rear plastic ac grate with ir gun 67* fired up generator turned rest ac an feels cool 15 min shot plastic ac grate again in same spot 48*Shut down rear and started front. Fan comes on but compressor keeps on trying to start every minute or so and cuts out. Removed wires from compressor and all have continuity. Switched all capacitors and compressor over load switch from working rear to front and no change. I guess compressor is locked up. Was thinking of trying a hard start kit but not sure it would work. Was thinking about trying to find a compressor but a quick search showed nothing. Gotta hop back on roof and get numbers off it. Here's a few pics.

Those ac units don't run on r22 is the first problem

If you are talking 1998, then Freon 22 is the Freon to use. BUT, most units use only 16 to 20 ozs of Freon. HOW did you determine the correct Freon fill capacity? There are only 2 ways to fill a Roof RV AC1. Dial a Charge2. Temp corrected amp draw AT the compressorRegardless, your Compressor is not caused by your fill. You have a bad compressor. YES(or NO) you will not find a replacement Compressor for a RV Roof AC unit. They have not made replacement compressors for more than 30 years as it was cheaper to replace the upper unit complete than pay to replace the compressor. DougPS, since you are handy brazing the lines, LEAVING the Line taps on is foolish. You only install Line Taps to safely(EPA) drain any possible Freon still in the system and then braze the Line Tap pin holes and braze in standard copper Schrader valves. Line Taps WILL LEAK. Eventually.

newman fulltimer wrote:Those av units don't run on r22 is the first problemHmmm pic of compressor and my owners manual were I found how much freon it takes

dougrainer wrote:If you are talking 1998, then Freon 22 is the Freon to use. BUT, most units use only 16 to 20 ozs of Freon. HOW did you determine the correct Freon fill capacity? There are only 2 ways to fill a Roof RV AC1. Dial a Charge2. Temp corrected amp draw AT the compressorRegardless, your Compressor is not caused by your fill. You have a bad compressor. YES(or NO) you will not find a replacement Compressor for a RV Roof AC unit. They have not made replacement compressors for more than 30 years as it was cheaper to replace the upper unit complete than pay to replace the compressor. DougPS, since you are handy brazing the lines, LEAVING the Line taps on is foolish. You only install Line Taps to safely(EPA) drain any possible Freon still in the system and then braze the Line Tap pin holes and braze in standard copper Schrader valves. Line Taps WILL LEAK. Eventually.I agree 100% on the line tap. I weighed the freon on a scale.I may just replace both as's. You have seen and worked on more of ac's than anyone on the forum. What brand would you recommend for replacement.

Mike, you should have ask the experts first, then you could have really screwed things up......GRIN. GOOD JOB.I bet you have the same card in you billfold that I do.It says, "your name" has been certified as UNIVERSAL technician as required by 40 CFR Part 82, Sub Part F.Richard

Rooftop ac repair | Good Sam Community

mike_brez
Explorer
Jun 29, 2019
Branson N Tucson wrote:
By your profile your MH is a 1998.
If they orginal units, you may consider replacing them. You sound very mechanical incline and could install them your self. There are some pretty low prices out there, I'm sure a compressor isn't cheap.

Yes thanks ordered and allready installed two new ac units and thermostat.
Looks like I will be uninstalling them:S
mike_brez
Explorer
Jun 29, 2019
Thanks guys. Should have flipped the old ones over an would have seen.
Now is it ok to flip these new ac's upside down to install the cups?
oldave
Explorer
Jun 29, 2019
Mike , assuming you still have the old units .
Go flip one over and you will see the little pans .
If they are ok just take them off go up on the roof and install
on the new A/Cs .
However it wont hurt a thing to leave as is and install later
the water will just run on the roof . .

The water drips into those pans then a hose goes inside the coach
there it ties into your drain system .
You are supposed to use 2 gaskets and cut a notch between
the 2 for that hose to pass through going inside , caulk it good .
The idea is the pans catch the water , carry it back inside then down
the drain hoses .
However if the drains get stopped up then the pans just overflow out
onto the roof instead of in the floor .
Pretty neat .
Branson_N_Tucso
Explorer II
Jun 29, 2019
By your profile your MH is a 1998.
If they orginal units, you may consider replacing them. You sound very mechanical incline and could install them your self. There are some pretty low prices out there, I'm sure a compressor isn't cheap.
dougrainer
Nomad
Jun 29, 2019
I would purchase 2 new drain cup kits from Dometic. After all these years the Plastic will be very brittle and will probably crack. That is what I would do if I was doing this for myself or a customer. Doug

https://www.vintagetrailersupply.com/Dometic-Air-Conditioner-Drain-Kit-p/vts-079.htm
mike_brez
Explorer
Jun 29, 2019
Thanks Dave. I didn't see any installation instructions but I'm guessing sence I allready installed the units I need to unbolt them from roof to install them.
oldave
Explorer
Jun 29, 2019
mike brez wrote:
Hey Doug my coach has a hose for each of the ac's so the water drips on the ground near my front tire and rear bumper instead of running off the roof.
Is their a way to do that with these ac's?

Not Doug but I think I can help .
That part of the units is an added part . It is 2 little plastic pans
that attach to the underside on the outside of the unit
They are held on by 2 screws and can be moved from the old A/C
I was concerned the plastic pans were old and fragile so I ordered
new ones . This is the kit, if it was me I would order 2 kits

https://www.ebay.com/itm/Dometic-3107688-016-Drain-Kit-System/292993702423?epid=1023679643&hash=item4437c91a17:g:AZUAAOSwrYRciatG
mike_brez
Explorer
Jun 29, 2019
Hey Doug my coach has a hose for each of the ac's so the water drips on the ground near my front tire and rear bumper instead of running off the roof.
Is their a way to do that with these ac's?
mike_brez
Explorer
Jun 23, 2019
oldave wrote:
Mike , Did you order a new thermostat too ? I'm pretty sure your old
one will not cooperate with the new units . The new thermostat is plug
and play same as the old one .

Your old thermostat may be worth more to someone than the old A/C units .

Measure the spacing of the 4 long bolts . Mine was slightly different
by just a small amount and I didn't know it , caused me a little grief.
I had to enlarge the holes where the bolts pass through a little .
Good luck

Thanks for the tip. I did get a new thermostate also.
oldave
Explorer
Jun 22, 2019
Mike , Did you order a new thermostat too ? I'm pretty sure your old
one will not cooperate with the new units . The new thermostat is plug
and play same as the old one .

Your old thermostat may be worth more to someone than the old A/C units .

Measure the spacing of the 4 long bolts . Mine was slightly different
by just a small amount and I didn't know it , caused me a little grief.
I had to enlarge the holes a little where the bolts pass through
Good luck

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