Radiator stack leak on our 2008 Monaco Camelot

[Ali-026]

I was working on the swing door for the radiator stack, and noticed one of the radiators' bottom part was soggy (#4 in the photo). Looking at the stack, there is the main engine coolant radiator #1 behind all of them, which is not visible in the photo. I've checked it from the inside where the fan is located, and did not see any leaks (thank goodness).

I am trying to figure out what #2, 3 and 4 does. I think #2 is the CAC, and either 3 or 4 is the transmission cooler perhaps.

I am planning to fix the leak myself if possible. Any suggestions on where the leak might be coming from and how to fix it would be greatly appreciated.

Thank you. 

[Robert92867]

3 is a trans cooler, 4 is a/c condensor, and you got 2.  So that looks like PAG oil seeping out.  Those micro-channel aluminum  a/c condensors are generally considered a throw away item, even if the crack is readily assessable, the aluminum is too contaminated to reliably weld.  A search for dash a/c related terms will yield many postings from qualified a/c techs on this forum. I'm not seeing any oil seepage around the o-ring fittings, so either a crack or migrating from somewhere else is my guess.  First thing I would do is clean the area well and try to spot the leak.

[Happycarz]

#2 is your CAC, intercooler. 
#3 should be your hydraulic cooler.  
The transmission cooler should be underneath between the radiator fan and engine, down low. It will be a square box 4” x 4” , 24” long (approx) with a radiator hose at each end two hydraulic lines.  

[Happycarz]

Model year 2008 Camelot had running changes, so mine is different than yours.  The components do the same thing, they’re just laid out differently  

Hope this helps.

 

 

[Bill R]

8 hours ago, Happycarz said:

Model year 2008 Camelot had running changes, so mine is different than yours.  The components do the same thing, they’re just laid out differently  

Harry, my cooling stack is very similar to yours.  Did you spray in the expandable foam in the voids on both sides?  Makes sense to keep air from bypassing the stack.

[Jetjockey]

Backtrack lines to the coolers and their purpose will be obvious. Then see if corresponds to previous posters observation. Because several are not in agreement. You may be able to find the leak by running the ac to build pressure.  Shut ac off and quickly spray  leak detector on suspect area while you still have pressure in the system. Don’t  addany internal leak finder as it can cause subsequent problems. This method usually works but not always. However it is quick and simple.. yours is likely  r134 which runs at higher pressure than r 12 did ,so that aids in finding the bubbles.

I am not a fan of Leak stop and won’t use it.

your condenser appears to be very accessible .if the system is not cooling it might make sense to replace condenser at this time. Good luck let’s us know what you find

Edited March 1 by Jetjockey
Addit

[Happycarz]

Bill,

Monaco got it almost right when spraying foam, but left some voids. I filled them in so all air had to travel through the cooling stack.
 

Every year I give the stack the Simple Green treatment. Then every two or three years I unbolt the condenser, cut the foam away from the A/C lines and swing the condenser out away from the CAC. This allows me a better cleaning of the CAC and radiator.

When leaving home when 110° and climbing 6% grades, I want the cooling system as close to 100% as I can get it.

 

Ali,

Does your dash A/C cool normally? If the condenser is leaking you would think the dash air would be hot.

 

[96 EVO]

On 2/29/2024 at 10:25 PM, Happycarz said:

Model year 2008 Camelot had running changes, so mine is different than yours.  The components do the same thing, they’re just laid out differently  

Hope this helps.

 

 

Your right!

Mine is laid out like Ali's

[Ali-026]

On 2/29/2024 at 3:10 AM, Robert92867 said:

...First thing I would do is clean the area well and try to spot the leak.

Thank you, and agreed. I did clean the area well and will try to spot the leak.

On 3/1/2024 at 9:11 AM, Happycarz said:

...Does your dash A/C cool normally? If the condenser is leaking you would think the dash air would be hot.

 

Good point, I was testing dash AC heating today, I set the temp to cold and Max AC, although the heater water shutoff valve was not fully closing, I did not notice any cold(er) air coming from dash vents. I checked the compressor on the engine as well, but could not tell if the clutch was engaging. 

Does this part on the compressor circled in red supposed to spin with A/C or Max A/C on? I've tried on and off but it was not spinning.

 

[96 EVO]

Yes, that will spin when / if the clutch engages.

[Benjamin]

The clutch won't engage if the refrigerant pressure is low, there is a low pressure switch to protect the compressor, and that is probably open if there is a leak.  You can get r134 cans that include a pressure gauge that is accurate enough to see if there is any pressure in the system.  If the leak is at a joint, then it might be as simple as an o ring.  Not kosher, but you can get away with replacing the o ring if there's still residual pressure in the system.  Correct would be to vacuum it down, then recharge after leak testing and a second vacuum. 

[96 EVO]

A failed evaporator temp control switch can also prevent the compressor clutch from engaging!

Discovered that a couple of months ago myself.

[jacwjames]

You can test by jumping the low pressure switch to see if the clutch engages.  If it does it probably means you have low freon.

When I first bout my coach in 2008 the AC wasn't working, clutch not engaging so I added one can of freon and it took off.  That lasted until ~2020 and it stopped working again.  Bought a set of gauges and my neighbor who does HVAC work sold me a large bottle of the 134-A refrigerant and charged my system.  Since I didn't open up my system I didn't bother with pulling a vacuum etc.  Had to add a little more this year.  If it gets much worse I'll have to put in some dye and look for the leak but adding a little refrigerant every 3-4 years will work for now.   There is a table in my manual that shows pressure based on ambient temp. 

[Ali-026]

Thank you for all your messages. I do have a set of gauges, and connected them to the ports in the firewall area. I see the following pressures. Is it safe to assume these are pretty low?

[jacwjames]

Is this with the engine off, either way it looks low.    

In your manual there is a table showing what the high pressure should be with engine running. 

 

[Benjamin]

10 PSI?  you don't have any liquid refrigerant left, unless you're well below zero there.  That's a good sign that you have some residual pressure though, that shows the system has not sucked air and moisture in yet, UNLESS it's been very cold and you took those pressures on a much warmer day than it had been.  Don't bother trying to run the compressor, there's no charge, and running could suck contaminants into the low side.