Skip to main content ↑ ↓
Topic: Heater hose to Water Heater/Heat Exchanger 8.3 (Read 730 times) previous topic - next topic

Heater hose to Water Heater/Heat Exchanger 8.3

I have a hidden coolant leak behind the water heater.  There are telltale red drops on the bottom of the water heater bay, they run while driving from side to side.  I have looked for all the obvious points in the water heater bay where the leak could come from near the water heater, and I find none.  I even removed the water heater from the rv and ran it partially outside to check for any leaks, and there were none visible.

What is the path for these hoses?

The only thread I could find where someone attempted to replace these Foretravel water heater heat exchanger hoses, is the following one.  It appears to just end, with no comments on the result.
heater hose/coolant line replacement

I appreciate any input.  Where do these hoses run to?  Does one go to the engine, or do both run up to the front of the rv heater core along side of the fuel lines?

Found my answer here:
Heater Hose to Check
97 U295 40, Build #5040, 6C8.3 325 HP
Oregon Continuous Traveler
Samsung Residential #RF20HFENBSR,
Xantrex SW2012, (3)AGM8D Hse, (2)AGM Grp24 Eng, Victron BMV-712, 1800w Solar 4 LG & 2 Sunpower
Extreme Full Body Pt w/hdlmps, new furn/floor, 4 down Lexus 2004 GX470 AWD curb weight 4,740 lbs
Prev: 1990 Barth, 10L 300 2 yrs; 91&92 Monaco Signature, 10 yrs, 10L C 300 &  6C8.3 300; 1997 ForeT 6C8.3 325 since May 2017.  Employed by Guaranty RV 14+ yrs.  Former VW New Car Dlr/Service Dlr, Sales Mgr, Rv Sales, and Service Adviser from 1968-2017
"Don't criticize what you can't understand" Bob Dylan

Re: Engine coolant leak, Water Heater Heat Exchanger hose replacement

Reply #1 –
Jack,

I have had some small leaks where the engine coolant hoses connect to the back of our OEM water heater.  I finally fixed them by putting two hose clamps on each hose.  Since you said you pulled your water heater (partially) out I am sure you inspected the hose connections.

I have luckily not had any other leaks in those hoses.  I don't know how the hoses are routed.  The "Close For Max Heat" valve supposedly shuts off flow to the water heater but does not stop flow to the dash heater.  This leads me to theorize that the water heater is on a loop which branches off the main hose running to the dash heater.  See my kindergarten quality diagram below.  Of course, I could be completely wrong.

I do not like to contemplate how hard it would be to replace the OEM coolant hoses.  Hope I'm never forced into that situation.


1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Engine coolant leak, Water Heater Heat Exchanger hose replacement

Reply #2 –
Qur water heater takes about 10-15 minutes to heat up,no engine heat,my opionion is less hoses,less things to leak.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Engine coolant leak, Water Heater Heat Exchanger hose replacement

Reply #3 –
Since no one responded to my question that replaced these hoses, I will solve my leak temporarily by putting a bypass of the heater core and heat exchanger on the engine, until I replace the failed hose.

I can do that easily by running a hose from inlet to outlet as a bypass, on the engine, or capping both off as a temporary solution.

Although I found no FT owners that replaced those hoses, I did find many links of Winnebago owners that have, as they used the same water heater with heat exchanger.  This also lead to the following Barth owner that replaced his on a similar 6C8.3

To aid any Ft owner that has a similar issue in the future, and that this will be a summer 2021 maintenance project, I'll update this thread at that time.

Monarch 8.3 Cummins cooling system - Topic
97 U295 40, Build #5040, 6C8.3 325 HP
Oregon Continuous Traveler
Samsung Residential #RF20HFENBSR,
Xantrex SW2012, (3)AGM8D Hse, (2)AGM Grp24 Eng, Victron BMV-712, 1800w Solar 4 LG & 2 Sunpower
Extreme Full Body Pt w/hdlmps, new furn/floor, 4 down Lexus 2004 GX470 AWD curb weight 4,740 lbs
Prev: 1990 Barth, 10L 300 2 yrs; 91&92 Monaco Signature, 10 yrs, 10L C 300 &  6C8.3 300; 1997 ForeT 6C8.3 325 since May 2017.  Employed by Guaranty RV 14+ yrs.  Former VW New Car Dlr/Service Dlr, Sales Mgr, Rv Sales, and Service Adviser from 1968-2017
"Don't criticize what you can't understand" Bob Dylan

Re: Engine coolant leak, Water Heater Heat Exchanger hose replacement

Reply #5 –
I sure like having hot water anytime I stop. Saves on propane as well, as I dry camp a lot.
1996 U295-36, Cummins 300hp, 8.3. Build number 4864. Vin number 1F97D536XTNO54271. Purchased October 31, 2019.

Re: Engine coolant leak, Water Heater Heat Exchanger hose replacement

Reply #6 –
Quote from: Twig –
There are current posts on this subject by al mata. Antifreeze solution leaking from under water heater

My leak is different than the post you point to.  In earlier posts on my thread I said I have no leaks on the back of the hot water heater or the hose sections in that compartment.  The leaks are on a portion of hose that runs above the fresh water storage tank.  It is either on the hidden part of the hose that goes from the heat exchanger to the engine or it is on the hose going to the heater core in front dash.  Even with water heater removed, engine running, leaks are not visible.  My temporary solution is to block at the engine the inlet and outlet, or loop.
97 U295 40, Build #5040, 6C8.3 325 HP
Oregon Continuous Traveler
Samsung Residential #RF20HFENBSR,
Xantrex SW2012, (3)AGM8D Hse, (2)AGM Grp24 Eng, Victron BMV-712, 1800w Solar 4 LG & 2 Sunpower
Extreme Full Body Pt w/hdlmps, new furn/floor, 4 down Lexus 2004 GX470 AWD curb weight 4,740 lbs
Prev: 1990 Barth, 10L 300 2 yrs; 91&92 Monaco Signature, 10 yrs, 10L C 300 &  6C8.3 300; 1997 ForeT 6C8.3 325 since May 2017.  Employed by Guaranty RV 14+ yrs.  Former VW New Car Dlr/Service Dlr, Sales Mgr, Rv Sales, and Service Adviser from 1968-2017
"Don't criticize what you can't understand" Bob Dylan

Re: Engine coolant leak, Water Heater Heat Exchanger hose replacement

Reply #7 –
Jack has your Motor aid been removed from your system or do you still have those hoses in the compartment?
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: Engine coolant leak, Water Heater Heat Exchanger hose replacement

Reply #8 –
Our 97 U 295 has 2 shut off valves at the back of the engine by the transmission. Maybe someone installed them.
When I did the new motor, I just shut them off, till I was ready to blow out the rest of the cooling system. I just replaced both the hose's to that point from the engine.

Someone mentioned double clamps. I actually double clamped every new hose on the engine at rebuild.

As a FT tech, one of my 1st jobs was to replace them front to back on an older FT, one that had a chassis (don't remember model) Man did I get dirty, not for the faint of heart.
Chris
Chris and Tammy White  CDA Idaho
Previous owners 1997 U295 36' 3126 Cat 300 HP Build # 4998
Former Foretravel tech & RVIA certified tech
Former owner Custom Satellite home/RV satellites 
Former owner Vans LTD  van conversions
Unemployed, panhandler, drag racer NHRA #6348

Re: Engine coolant leak, Water Heater Heat Exchanger hose replacement

Reply #9 –
Maybe one like mine Chris?

https://www.foreforums.com/index.php?action=dlattach;topic=26970.0;attach=37204;image
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: Engine coolant leak, Water Heater Heat Exchanger hose replacement

Reply #10 –
Quote from: craneman –
Jack has your Motor aid been removed from your system or do you still have those hoses in the compartment?
Craneman, New water heater w/heat exchanger, new hose to cutoff to heat exchange system, new cutoff valve.
97 U295 40, Build #5040, 6C8.3 325 HP
Oregon Continuous Traveler
Samsung Residential #RF20HFENBSR,
Xantrex SW2012, (3)AGM8D Hse, (2)AGM Grp24 Eng, Victron BMV-712, 1800w Solar 4 LG & 2 Sunpower
Extreme Full Body Pt w/hdlmps, new furn/floor, 4 down Lexus 2004 GX470 AWD curb weight 4,740 lbs
Prev: 1990 Barth, 10L 300 2 yrs; 91&92 Monaco Signature, 10 yrs, 10L C 300 &  6C8.3 300; 1997 ForeT 6C8.3 325 since May 2017.  Employed by Guaranty RV 14+ yrs.  Former VW New Car Dlr/Service Dlr, Sales Mgr, Rv Sales, and Service Adviser from 1968-2017
"Don't criticize what you can't understand" Bob Dylan

Re: Engine coolant leak, Water Heater Heat Exchanger hose replacement

Reply #11 –
Quote from: craneman –
Maybe one like mine Chris?

https://www.foreforums.com/index.php?action=dlattach;topic=26970.0;attach=37204;image
That would be it.....Makes me tired and dirty just looking at it!
Chris
Chris and Tammy White  CDA Idaho
Previous owners 1997 U295 36' 3126 Cat 300 HP Build # 4998
Former Foretravel tech & RVIA certified tech
Former owner Custom Satellite home/RV satellites 
Former owner Vans LTD  van conversions
Unemployed, panhandler, drag racer NHRA #6348

Re: Engine coolant leak, Water Heater Heat Exchanger hose replacement

Reply #12 –
Jack, so you have two hoses which one of them has a hole in it. Can you isolate them, then drain any coolant out of them, then plug one end of each hose and put low pressure air in one hose at a time and listen for an air leak? At least you would know which hose it is and /hopefully trace the air leak to where it is. Just a thought.
Richard & Betty Bark & Keiko our Golden Doodle
2003 U320T 3820 PBDS
Build # 6215
MC # 16926
2016 Chevrolet Colorado 4X4 diesel

Re: Engine coolant leak, Water Heater Heat Exchanger hose replacement

Reply #13 –
If I recall when I had my water tanks out, I traced the hoses to TEEs in the area above the rear axle inside the cable tray. They weren't  really TEEs but more like WYEs.

Like rbark, I'm thinking maybe it only leaks when there's pressure;  just running the engine cold might not be enough and it has to be up to temperature to get the pressure up.
John Fitzgerald
1991 U300 (SAI) Side Aisle Island Bed 40'
Detroit 6V92 with Allison Retarder
Meridian (Boise), Idaho

Re: Engine coolant leak, Water Heater Heat Exchanger hose replacement

Reply #14 –
rbark, JohnFitz, gracerace, craneman and and all, thank you.  That will be the plan.  Rv is in storage now, so I will try that when I can, spring 2021.

For anyone new finding this thread, search "heater hose".  Posts there answered all my questions.

This is a marine 8.3, however it shows the two heater hoses and where they go, problem solved.  It is necessary to double click on the picture for it to expand and see #6 and #7 heater hoses.
6CTA 8.3 430/450 Diamond Engine Hoses - Seaboard Marine

and thank you jor for these pictures
Heater Hose to Check   






97 U295 40, Build #5040, 6C8.3 325 HP
Oregon Continuous Traveler
Samsung Residential #RF20HFENBSR,
Xantrex SW2012, (3)AGM8D Hse, (2)AGM Grp24 Eng, Victron BMV-712, 1800w Solar 4 LG & 2 Sunpower
Extreme Full Body Pt w/hdlmps, new furn/floor, 4 down Lexus 2004 GX470 AWD curb weight 4,740 lbs
Prev: 1990 Barth, 10L 300 2 yrs; 91&92 Monaco Signature, 10 yrs, 10L C 300 &  6C8.3 300; 1997 ForeT 6C8.3 325 since May 2017.  Employed by Guaranty RV 14+ yrs.  Former VW New Car Dlr/Service Dlr, Sales Mgr, Rv Sales, and Service Adviser from 1968-2017
"Don't criticize what you can't understand" Bob Dylan