Chassis heat problems

[Gregory OConnor]

Don, Your theory sounds good. running the pump wet ,primed and
against a closed supply is like trying to get fuel out of an
unvented tank.

Wonder if it is just bearings in the pumps motor or crap in the
impeller (which will screw the bearings anyway). I would pull the
pump and bench test it maybe some one knows the amp dray it is
designed to pull. if it pulls more on the bench with a goud source,
chances are it is time for a new. If the Sporlan is a vacumn
Diaphram valve they fail to close more often then fail to open. If
it is a valve problem it may well be crap on the supply side of the
sporlan or a screen doing what you describe to the pump.

GregoryO'Connor
94ptRomolandCa

--- In WanderlodgeForum@yahoogroups.com, "Don Bradner"
wrote:
>
> Until a few days ago, my chassis heat was working fine, now it is
dead.
>
> The chassis heat on this coach is a lot simpler than has been
described for many others. No summer/winter valves, no always-on
Sporlans, no Webasto or Primus.
>
> The water system consists of a single Sporlan valve and a pump,
both actuated by a slide switch in the cockpit (below the backup
monitor controls). The valve should open and the pump turn on
whenever the switch is in the Warm position and the ignition key is
on.
>
> When this is done (engine off in order to hear things), there is a
discernible click at the Sporlan, and the pump starts. After a few
seconds, a circuit breaker can be heard to pop, and it goes off.
Maybe ten seconds later the breaker resets and things run for a few
seconds more.
>
> Question: Could this be a stuck Sporlan (pump blowing breaker
because of back pressure)? I've looked through the various documents
available and don't see a good way to test a Sporlan valve.
>
> Don Bradner
> 90 PT40 "Blue Thunder"
> Posting today by satellite from Pea Soup Andersen's, Santa Nella,
CA
>