Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: Dave Katsuki on July 07, 2010, 01:39:47 am

Title: Heater core replacement
Post by: Dave Katsuki on July 07, 2010, 01:39:47 am
Report:

I discovered a couple of weeks ago that the dash heater core on our 1999 U270 was leaking - saw slow drips out of the dash  AC  drain hose  on the passenger side behind the upper corner of the generator door.  I ordered a new one from FT, and got it replaced it today.  It was fairly straightforward to replace it, but there is a lot of stuff to remove to get to it.    The good thing is that you can do it all inside the coach, standing or sitting, in air conditioned comfort (it was really hot outside today!)  Here's a blow-by-blow, if you need to do it: 

Outside, through the generator door (passenger side), the heater valve is easily accessible.  I clamped the heater hoses to keep the engine from draining,  and  removed the heater valve to allow the core to drain.

Inside,  detached the two swing-up dash covers from their hinges, then the passenger side vertical trim panel nearest the windshield, and the horizontal trim piece over the breaker panel cover, removed the defroster ducts, and then was able to pull up the padded dash cover which is held down by velcro.  Next, lifted out the center electrical service panel and removed the center console, which is held onto the floor and frame by 6 or 7 long screws.    Labeled and removed all the air duct hoses from the air box.

The air box is held in place by two screws through a vertical angle into the dash frame on the left side, and by two screws into the floor at the front.  Once it's loose, it can be eased forward a little which makes access easier, but it was not possible to move it very much, since the stiff AC hoses prevent any significant movement. 

After loosening the box, it's simply a matter of removing many many screws holding the sheet metal pieces on and finally getting access to the top of the heater core which you can see through the flap opening after taking the first sheet metal cover off.  You have to take the control levers off the flap motors, and lift out the two flap assemblies, so it's helpful to mark the flap positions before removing.  (I forgot to do that, but it's not hard to figure out the right motor / flap positions by moving the controls to different settings and watching the motors.)  Finally, to remove the core, I took all the screws off the right side plate, and then detached the hoses (be prepared for more coolant draining!) and worked the core up from the left side.  New core went in the same way.


Title: Re: Heater core replacement
Post by: George Stoltz on July 07, 2010, 02:25:19 am
Dave,

Well done.  You saved a ton of dough.  Now you can do mine ;D -- if it ever leaks.
Title: Re: Heater core replacement
Post by: Raymond Jordan on July 07, 2010, 03:55:33 pm
Hi Dave,
  Thanks for the well done report. The pictures sure made it nice.
Title: Re: Heater core replacement
Post by: smillner on November 21, 2012, 10:56:54 am
Thanks so much for write up and pictures on this one, it helped me alot.  I did mine this weekend - lots of screws!

Steven
Title: Re: Heater core replacement
Post by: Dave Katsuki on November 21, 2012, 03:33:28 pm
You're quite welcome.  Once you start taking cabinet pieces apart, you quickly realize that a large part of the coach weight is screws :)) .    Could probably hit a brick wall head on and not shake any wood parts loose.
Title: Re: Heater core replacement
Post by: Roger Berke on November 21, 2012, 08:08:39 pm
Dave

Do you have an Aqua-Hot?  Rudy Legett and I do not understand how the engine heats the dash AND the Aqua-Hot.  Are there dual heat exchangers (one for engine coolant the other with Aqua-Hot coolant?

- Roger -
Title: Re: Heater core replacement
Post by: Gary Bouland (RIP) on November 21, 2012, 09:10:47 pm
Roger, I'll jump in with my opinion.
The dash heat is provided by engine coolant circulated to the front of the coach and then thru the coil, air is circulated by the Fans for Defrost/heat etc.

In addition even without Aquhot on some coaches the same coolant passes thru the propane fired water heater to provide water heating, sometimes known as Motoraide. 

I suspect that the Aquahot has the same type coil  in it so that engine coolant can circulate thru it also.
Gary B
Title: Re: Heater core replacement
Post by: Roger Berke on November 23, 2012, 01:07:33 pm
I just received this note from David David VanAmburg about his coach.  His problem was that the Aqua-Hot dash fans were not working.  Dave has a 1999 U320.

Quote
I repaired the dash fan and thought I would share with you what the problem was in case you ever run into a similar problem.  First though, I need to say that I was incorrect about there being just one dash fan ..... turns out there are two.    One blows thru the automotive heater core, and one blows thru the Aqua-Hot core.  Both exhaust thru the dash vents. 

The original suspicion was that a relay had failed.  After receiving the wiring diagram I tracked down the circuit and determined the relays were fine.  It turned out to be a failed Bridge Resistor (small square ceramic and metal block with 4 male spade connectors).  There are 5 of these located near the vacuum control module under the center tilt up cover.  I had to source a new one from the web ..... but very cheap.  The part# for the bridge rectifier I used is KBPC2510 and a Google search will give numerous sources.  The Foretravel application only uses the DC connectors.


This explains much better how the Aqua-Hot and engine heating system heats the dash.

- Roger Berke -
2000 Foretravel U320