Recharging Dash Air

[Doc Mark]

Anyone done this themselves? We noticed as we left FL that the only way to keep the interior cool was to run the genset & roof AC's. The dash air just wouldn't put out enough cold air.

I haven't measured the temp, but I know by feel that the air is not cool enough exiting the vents.

We are parked for the summer and no one will come on-site to recharge the unit. Walmart et al sells the R134 kits for the do-it-yourselfer and I thought about giving that a shot.

Any suggestions as to how to do this? I have done cars years ago with the R-12 systems but know nothing about the R-134 setup.

Mark

[bdpreece]

Just bought a kit at O'reilly auto parts a couple of days ago. $34.99 plus tax. I purchased the largest one they had believe it was either 22 or 28 ounce can of freon. Just followed the directions on the can it was simple. Make sure that you get the kit that allows you to re use the gauge on a second can as one can will probably not be enough. I put in the entire can and the pressure barley raised. Found someone else on another board who had done one and he said his took three cans of freon.

[Romeo]

I have the same problem and contemplating on how to go about resolving it.

In the past I have been told that AC freon will not be low (and need to be re-charged) unless there is a leak, and if the system leaks, the leak needs to be repaired. I have also been told that there are certain conditions that require that the system needs to be "purged" and recharged to get it operating properly.

The last time I tried one of the auto part store's re-charging kits, it made no difference in my Tahoe's AC. So, I took it to the shop and they found that the system needed a minor part. It was replaced and the AC worked fine. They also purged the system and recharged it since the system had to be de-charged to install the new part.

Since I don't think there is anything I can do to solve the problem, I guess I will have to find a shop where I can take the coach.

[quadnkev]

The process is the same, it is a different type of refrigerant that is used and the fittings are not the same as R-12.
You are just sort of filling a tire with a leak at this point and should have it inspected by someone that can repair it correctly. Running it with low pressure can cause compressor damage as there is also a loss of oil usually associated with leaks.

[SPICoaster]

If your dash AC is from Evans then the only way, per Evans, to properly charge the unit is to discharge the unit using a recovery system and then recharge with the appropriate amount of freon. See their web site for full details on why you can't determine the amount of freon in their systems by only reading pressure, etc.

And if your system is low you need to find the leak and fix it, otherwise you get to make the repair a few times each year.

[Romeo]

Originally Posted by SPICoaster

If your dash AC is from Evans then the only way, per Evans, to properly charge the unit is to discharge the unit using a recovery system and then recharge with the appropriate amount of freon. See their web site for full details on why you can't determine the amount of freon in their systems by only reading pressure, etc.

And if your system is low you need to find the leak and fix it, otherwise you get to make the repair a few times each year.

Here is a Evans-Tempcon link: Evans Tempcon, Inc - Owners Resources

[tyka]

I have the same problem and did the same thing coming back from Florida. Bought the Walmart kit and could not recharge the system as I once did for my CR-V. The systmem wouldn't take it, the gage got up to about 90 psi and the hose expanded. Waste of time and $. I asked a mechanic back home and he said I should take it to an AC shop get it purged and tested for leaks. It's on my list of to do things.
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04 MACA 3778 / 08 CR-V

[Renden]

Just got my Dash AC done by a Specialist in Quebec City at the same time as my annual maintenance - The process is scientific 1) checking for leaks using Nitrogen - they found a leak at the rear level (Cummins motor) and that was repaired -2) re-checked for any other leak in the system before putting oil and new freon and verification of AC temperature at the outlets 3)- Done
It is nice to see that experienced people can do the job correctly - you pay for the service but the results are there......and they also found that the AC strap (belt) at the motor was used and it was replaced

[BFlinn181]

Are you sure the heater valve is fully closed? If it is open a bit, you've got heat fighting cool. Feel hoses for heat going in and out of heater core to be sure no coolant is flowing through heater.

[pkmesser]

Originally Posted by tyka

I have the same problem and did the same thing coming back from Florida. Bought the Walmart kit and could not recharge the system as I once did for my CR-V. The systmem wouldn't take it, the gage got up to about 90 psi and the hose expanded. Waste of time and $. I asked a mechanic back home and he said I should take it to an AC shop get it purged and tested for leaks. It's on my list of to do things.
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04 MACA 3778 / 08 CR-V

If you showed 90 psi, with the compressor running, you were probably hooked up to the high pressure side, the low pressure side will be under 50 psi. You have to be hooked to the low pressure side of the system to charge it. Now, if you were hooked to the high pressue side, with compressor running and showing 90 psi, you had a very low charge. Typical high pressue side will be in the 300 psi range. The kits will charge the system, if hooked up properly. However, one should also be monitoring the high pressure side to check for other problems, and the kits are not set up to do that. The concern being if the expansion valve is not functioning properly or you have a system blockage, you can take the high side pressure too high by overcharging, and subsequently damage the compressor. I think it is ok to charge with one of the kits, but only add enough of the 134 to get reasonably good cooling, and be on the low side of the reccommended pressure as shown by the kit for the ambient conditions. (read the instructions!) This should be looked at as a temporary fix. I carry a kit, and one can of freon just for that reason. But I would not consider it to be a permanent repair!

[AndrewC]

Bonjour Randen
i am also from quebec and i have a Kountry strar where do you go
for your maintenance
merci André

[Mr_D]

On our 41' DSDP I was told it takes something over 2 lbs to recharge the system. May take ours in tomorrow as it's quit. The compressor clutch isn't engaging so there are several things that could be wrong.

[tyka]

I found only one fitting than matches the fitting with the kit and according to the schematic I believe I was connected to the right one. I should have mentionned that when I connect the kit there's almost no reading on the gage until I give it a squeeze then it sky-rockets. The A/C hose is cold but not very cold and will supply enough when the outside temperature is under 77 degrees or just about.

[Chaffeekid]

Hey Doc, yes, I have done this several times with different MotorHomes I have owned. My current one had several problems with the dash air that I had to correct, including putting a belt on the compressor and adding refrigerant to the system.

Its really not a chore at all. The connector for my system is on the firewall at the front of the MH, under the little hood. The connector on mine was easy to identify as the cap has a large L on in for the low pressure side.

As has been said follow the directions on the can, the connector will only fit on the low pressure side, also get the one with the gauge on it that has a screw down T handle on the top of the can. This can be used on the other refill cans that are much less expensive.

The motorhome must be running and the AC system on with the ac fan on high. Connect the can to the LOW pressure side of the system and follow the directions for rotating the can from 12 to 3 while filling the system. Watch the gauge and check for the pressure compaired with the ambient air temp. It will probably be low.

I put two large cans in mine, and got really cold air from the dash, I have bought one other smaller can and hold that in reserve. I purchased mine from Lowes and the product name was Sub Zero and it has a leak preventive in it along with the pag oil that the compressor needs.

Anyhoo, that's the way I did it and now have really cold air from the Dash Vents and more money in my pocket than if I let someone else do it

Hope this helps
Happy Trails
Jim