When I was fighting this battle I went to extreme measures to insure the
combustion air loop was totally sealed.  I was also getting some odors
inside the van when running on propane that I wasn't sure about.  I thought
they might be exhaust.  I took the fridge out and everything looked good
and sealed.  Took combustion chamber apart, all seals looked good.  Now it
gets weird.  I sealed up all the holes in the system except the actual
exhaust pipe.  I armed myself with a spray bottle filled with soapy
water.  Then I got my sweetie to wrap her lips firmly around the exhaust
pipe to make a good seal, and blow.  I took the soapy water and sprayed
everywhere that I thought a leak might occur.  I found them at the various
openings of the combustion chamber that I thought were well
sealed.  Sweetie confirmed that air was going somewhere when she was
blowing.  I took the combustion chamber apart and added a little high temp
silicon sealer to all the seals that were leaking.  This sealed it up
good.  Afterwards sweetie reported air was no longer disappearing when she
blew into the system.

I can't say that something else might have happened during my R & R
procedure that might have improved  things with my fridge on propane
system, but I can say this:  Before this endeavor it was hard to light the
fridge and it blew out when driving.  Now it is easy to light the fridge,
and doesn't blow out on the hwy at 75 mph, in the car wash, etc.  Just went
3 days and over 500 miles on propane the whole time, never a stumble.  Now
if it would only keep the fridge really cold in hot weather!

Edward