Community Forums

mmorgan · 05-29-2017, 07:52 PM

My dash AC has been working great since I bought the coach last year, however my heater core needed changing. It is currently in the shop and heater core was changed but when they tried to recharge the AC with Freon they are having issues.

First problem was they could not locate a tag indicating the capacity of the unit so they were having to add Freon very slowly to avoid overfilling.

Second problem was the pressures were too high and he said probably has a piece of trash somewhere blocking flow so they sucked out the Freon again and started over and the second time had the same result.

They will continue working on it tomorrow but hopefully someone here has had this problem before and I can pass the information along to the shop?

Kennzz05 · 05-29-2017, 08:01 PM

You need a professional for starters
You really need to find the correct amount of refrigerant but it can be gotten close with knowledge and gauges that being said. Anytime the system is opened up for more then a few minutes you need to replace the filter dryer receiver(all one item) this hopefully is the issue with yours.additionally you MUST evacuate with a vacuum pump for a minimum of one hour prior to charging. If they tried to charge without pulling a vacuum find another shop Here is an example of the part I'm referring to the filter dryer

Kennzz05 · 05-29-2017, 08:03 PM

Picture opens when I tap on it
If it dosent google truck dryer receiver then go to images heading under the Google search

Kennzz05 · 05-29-2017, 08:18 PM

http://www.evanstempcon.com/tsg_Refr...hargeGuide.php

mmorgan · 05-30-2017, 05:04 AM

It is at a diesel truck repair facility. They did use the machine to pull a vacuum on the system as stated above.
He did make a comment about the system did not have a dryer like most systems. If it does it is very well hidden.
Photos attached that were taken a few months ago before the heater core installed.....as you can see there is no dryer anywhere in the system.

twinboat · 05-30-2017, 07:01 AM

If they left the hose ends uncovered, a price of dirt could have gotten in to the system, blocking the expansion valve.
That will give them the high pressures they are getting.

A good AC guy can repair an AC system without knowing exactly how much the system holds.

mmorgan · 05-30-2017, 07:22 AM

Yes, that is what they think happened.

oldmattb · 05-30-2017, 07:30 AM

If like my 1998 Windsor, the AC dryer is in the engine compartment. It looks just like Kennzz's photo.

Our dash heater core started leaking earlier this year. I bypassed it in a campground. It seemed easy enough to use the RV heater on cold days. I didn't want to disturb our still-working dash AC.

Matt B

mmorgan · 05-30-2017, 08:29 AM

Yes, that's exactly what I did last summer when it started leaking, but finally decided to get it working but now I have a heater and no air-conditioner, not a good trade, Lol

Kennzz05 · 05-30-2017, 11:07 AM

Quote:

Originally Posted by mmorgan

Yes, that is what they think happened.

Having a very hard time believing there is no dryer. If they didnt take any precautions like covering the ends of the line with tape or rags or something. I'd say the repairs are on them

reride · 05-30-2017, 01:28 PM

When I had ac problems last summer and I replaced dryer, I found it in the engine compartment just in front of the condenser.

Every ac system should have one, it filters moisture and other contaminants from the system.

Steve

8.3Oilbuner · 05-30-2017, 01:52 PM

Hi Mmorgan: Sorry to hear about your a/c problems. I called Monaco tech. back when you could get good info from them. Somewhere I have the amount of Freon for a 34' Windsor but have not been able to find it. I do know it was 4+ pound range. As for the dryer, on my previous 2000 32' Windsor and now my 2001 34' Windsor, the dryer is in the engine compartment. Lift up the bed and open the engine compartment hatch. Look straight down at the front of the compartment on a cross member at the front of the compartment. You will see the sight glass and the two hoses connected to the dryer. Hope this helps.

mmorgan · 05-30-2017, 02:18 PM

Thanks, I will call the shop and advise them

RobRoy · 05-30-2017, 05:10 PM

Quote:

Originally Posted by twinboat

If they left the hose ends uncovered, a price of dirt could have gotten in to the system, blocking the expansion valve.
That will give them the high pressures they are getting.

A good AC guy can repair an AC system without knowing exactly how much the system holds.

CORRECT!

The accuracy of the CORRECT fill depends on the all the components in the a/c system INCLUDING the length of the a/c hoses and keep in mind the length of those hoses vary from coach to coach model to model depending on how the a/c hose runs thu the coach.

To fill it correctly you need to know ambient air temps humidity and hi-low gage readings and you will get it filled accurately and correctly.

But first to diagnose this correctly we need A /C gages and gage readings both high & Low side pressures ( or vacuum) . I would like to know how much refrigerant was installed when taking the gage readings after doing so .... is the condenser ....is fan running?

In a normal situation ( not yours ) ...I would start by add 2.5 lbs thu the low side and then see what you have for gage readings, it will vary and depend on ambient air temp and humidity but this will give you an idea if the system is somewhat capable of functioning correctly.

I have no idea of what the OP has for a system but looks like that it uses an expansion valve and if so a pretty good chance that it's stuck. That is pretty common and can in many cases be coaxed into the opening with a low refrigerant charge and a heat gun or hair dryer on it for a min or so ..... you will see on the gages when it opens ( pressure changes )....then the system can be filled from there.

As far as a receiver? I have never seen a mobil system A/C without a dryer ( perhaps so..Ive just never seen one ) ...... my guess it's mounted on or next to the A/C condenser.

I'll take a stuck expansion valve for ! 10.00 Alex

If it were me?

1. Recover the refrigerant.

2. Pull the system to a good vacuum and make sure it holds

3. Because of the issues you have had thus far I would add .5 pounds increments of refrigerant at a time and watch the gages.... in most cases if the expansion valve is stuck ( and is common) nursing the refrigerant refill in small increments can help coax it open and if not try you wife's hair dryer ( at the risk of her killing you )

I'm not A/C expert but have stayed at a Holiday Inn Express a time or two.

Happy Hunting[/I][/FONT]