Skip to main content ↑ ↓
Topic: AquaHot coolant leak - inside main case (Read 1327 times) previous topic - next topic

AquaHot coolant leak - inside main case

Looks like I have a AquaHot coolant leak inside the main center case. 

Level on the overflow bottle is dropping 1" plus per day.  See visible seeping below the case.  Smell the coolant in the bay.

No drips under coach.

Seepage burns away and never drips under coach. Overflow bottle was full to line yesterday, 24 hour loss shows in currrent level. 2 photos show where the seepage is.


I'll PM Rudy in a minute as well.
Dan - Full timing since 2009
2003 U320 40' Tag 2 slide

Re: AquaHot coolant leak - inside main case

Reply #1 –
20250209_143953.jpgShort term is attempt to slow the leak using Barrs Stop Leak
Dan - Full timing since 2009
2003 U320 40' Tag 2 slide

Re: AquaHot coolant leak - inside main case

Reply #2 –
Longer term, 95% sure I will have Rudy and his crew install a John Carrillo rebuilt (reman) AH unit in late May to early June (in Katy TX).  Even if the stop leak works, I see that as short term, and don't want a future failure in winter weather.


I'm also due tires this year, now at 7 years on the Continental HSL2Eco H rated. Due Cummins, Gen, and chassis service as well this year. 

 Going to be an expensive year.
Dan - Full timing since 2009
2003 U320 40' Tag 2 slide

Re: AquaHot coolant leak - inside main case

Reply #3 –
You need to look inside. It might be something much simpler than a new tank.
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: AquaHot coolant leak - inside main case

Reply #4 –
Quote from: craneman –
You need to look inside. It might be something much simpler than a new tank.

I'm not sure how to look inside.  I looked down from the neck fill, and pulled the cover over the electric element and looked in there.  My outside cover has been off for a year or so. Inside metal cover looks riveted on.
Dan - Full timing since 2009
2003 U320 40' Tag 2 slide

Re: AquaHot coolant leak - inside main case

Reply #5 –
Look for DSD's post on rebuilding the AH.
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: AquaHot coolant leak - inside main case

Reply #6 –

Don't experiment with automotive radiator stop leak like Bar's...you may clog everything in the system.  Use a product designed for hyrdronic cast iron boiler leaks.  I used Silver King anti-foaming Safe sealant successfully.  Amazon.com: Silver King SBSL 1 Quart SAFE LIQUID BOILER STOP LEAK With...

Quote from: AC7880 –
[attach type=thumb]139589[/attach]Short term is attempt to slow the leak using Barrs Stop Leak
As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.
2001 4010 U320 build #5865 "Bluto-d-Bus" since 09/18
2006 Honda Element ESP Toad
Full timing since 2016 in Western MT
Copilot: Sitka
1975 GMC 260 Avion: sold

Re: AquaHot coolant leak - inside main case

Reply #8 –
So I did not work on the boiler internally. Just the transfer coils outside of the burner. I did have a coolant loop leak for the engine loop. It was external and was a cold solder joint.

Re: AquaHot coolant leak - inside main case

Reply #9 –
Quote from: dsd –
So I did not work on the boiler internally. Just the transfer coils outside of the burner.

Dan's being an '03 has a different AquaHot than a 2001.  I believe the domestic coils are internal - or at least in contact with the heat transfer fluid (and the fluid is thus GRAS boiler fluid, not ELC antifreeze.)
Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

2000 U320 36' non-slide / WildEBeest Rescue
2003 U320

Re: AquaHot coolant leak - inside main case

Reply #10 –
There still would be copper pipes inside the box that could be leaking.
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: AquaHot coolant leak - inside main case

Reply #11 –
If that '03 AquaHot has a radiator filler cap, I would be taking a close look at the filler neck area. It is a known source for leaks.

Bob
Bob & Suzy
2000 U320 4010 SPEC
2006 Honda CRV

Re: AquaHot coolant leak - inside main case

Reply #12 –
Quote from: Beerslayer_24 –
If that '03 AquaHot has a radiator filler cap, I would be taking a close look at the filler neck area. It is a known source for leaks.

Bob
Yep, first thing I checked. No joy
Dan - Full timing since 2009
2003 U320 40' Tag 2 slide

Re: AquaHot coolant leak - inside main case

Reply #13 –
I have had two such leak puddles like that over the years. One was a cracked sensor body, the other it was the radiator cap would seep when hot. I found that one when I felt the insulation was wet at the neck

Re: AquaHot coolant leak - inside main case

Reply #14 –
Quote from: e4services –
I have had two such leak puddles like that over the years. One was a cracked sensor body, the other it was the radiator cap would seep when hot. I found that one when I felt the insulation was wet at the neck
Where is the sensor body located?
Dan - Full timing since 2009
2003 U320 40' Tag 2 slide

Re: AquaHot coolant leak - inside main case

Reply #15 –
Quote from: Woody & Sitka –
Don't experiment with automotive radiator stop leak like Bar's...you may clog everything in the system.  Use a product designed for hyrdronic cast iron boiler leaks.  I used Silver King anti-foaming Safe sealant successfully.  Amazon.com: Silver King SBSL 1 Quart SAFE LIQUID BOILER STOP LEAK With...

By the time I had read your post, I already had used the Barrs Tablets in the photo I posted (i had them on hand). I used the entire pack - which says treats 3 gallons (AH is around 15 gallons).  I crushed them and mixed it with coolant to install.

So far so good, new post coming.
As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.
Dan - Full timing since 2009
2003 U320 40' Tag 2 slide

Re: AquaHot coolant leak - inside main case

Reply #16 –
3 days ago I used the Barrs stop leak tablets that I posted the photo of the empty package (above).

Seepage is stopped and coolant overflow bottle no longer dropping level. Might last, may not. New leaks may occur, or may not.

Now the big decision. Trust the stop leak long term and do not replace the AH this year. Or bite the bullet and replace it now (early June) as PM to prevent a future failure in cold weather.

No way to view current failure point and see if it looks like it may fail in multiple locations.

On the Cummins radiator, I had seepage, used the same stop leak, and had no further issues (used twice, once on old coolant, and once again after all new coolant). That seepage appeared to be around the end tanks.  So it worked and is working long term on main engine radiator.

Any thought on what to de regards replacing with rebuilt AH this June, or to let it go with the stop leak as is?
Dan - Full timing since 2009
2003 U320 40' Tag 2 slide

Re: AquaHot coolant leak - inside main case

Reply #17 –
Quote from: Woody & Sitka –
I used Silver King anti-foaming Safe sealant successfully.
How long ago was this?  Was it seepage that it fixed? 
Dan - Full timing since 2009
2003 U320 40' Tag 2 slide

Re: AquaHot coolant leak - inside main case

Reply #18 –
I used the silver king sealant as well when I notice a VERY minor seep through the bottom by the exhaust.
It has worked magnificently
No issues.
Peter    Alberta Canada
'98 U320 40'  Build 5359 M11 450 HP, Aqua hot, Blu Ox

Re: AquaHot coolant leak - inside main case

Reply #19 –
Quote from: Woody & Sitka –
Don't experiment with automotive radiator stop leak like Bar's...you may clog everything in the system.  Use a product designed for hyrdronic cast iron boiler leaks.  I used Silver King anti-foaming Safe sealant successfully.  Amazon.com: Silver King SBSL 1 Quart SAFE LIQUID BOILER STOP LEAK With...

If "safe" means NSF/potable, it might be okay for the 2003 and newer AquaHots.  When I Googled it, one link stated not to use in boilers with submerged coils, though.  Which also makes me wonder about Bar's...
As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.
Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

2000 U320 36' non-slide / WildEBeest Rescue
2003 U320

Re: AquaHot coolant leak - inside main case

Reply #20 –
Just don't drink the water out of the tap without running it through an RO filter.  Case closed.
2001 4010 U320 build #5865 "Bluto-d-Bus" since 09/18
2006 Honda Element ESP Toad
Full timing since 2016 in Western MT
Copilot: Sitka
1975 GMC 260 Avion: sold
 

Re: AquaHot coolant leak - inside main case

Reply #21 –
I added that to my Coach radiator 3 years ago. Still no leaks