finding water leaks in dry weather

[chuck botts]

One method is to pressurize the coach with a very low pressure fan, wash
the outside of the coach down with high sudsing detergent and watch where
the leaks blow bubbles. Use a washing brush to investigate every seam. Air
will blow bubbles even where water will seep in. This is the same technique
in finding an air leak in an inner tube. It doesn't take much air pressure
to blow a soap bubble.

High volume low pressure fans are used to pressurize balloon buildings,
toys and advertizing. The pressure is low enough that you can walk in and
out of the "blown up building" without really feeling the pressure change.
Check the safety dump valve to make sure that pressure cannot be built up
inside and blow something out.

 

[robert teed]

>
> One method is to pressurize the coach with a very low pressure fan, wash
> the outside of the coach down with high sudsing detergent and watch where
> the leaks blow bubbles. Use a washing brush to investigate every seam. Air
> will blow bubbles even where water will seep in. This is the same
> technique
> in finding an air leak in an inner tube. It doesn't take much air pressure
> to blow a soap bubble.
>
> High volume low pressure fans are used to pressurize balloon buildings,
> toys and advertizing. The pressure is low enough that you can walk in and
> out of the "blown up building" without really feeling the pressure change.
> Check the safety dump valve to make sure that pressure cannot be built up
> inside and blow something out.
>
I got the same results by running the roof air. That
produced enough inside air pressure to cause soap
bubbles on the roof and around the windows.
Im sure if I replaced the worn felt in the window track
I would get even more air pressure.
Rob Teed
74' Painted Desert
Lansing,Mi

 

[none]

Chuck......I spoke to a Greyhound maintenance man years ago and he said
they've been finding leaks in their busses this way since the 1930's. Only
they do it the easy way. They just turn on the heater blower
motor........Jim Davis, 77 Coca Cola, Oregon

- -----Original Message-----
From: Chuck Botts [SMTP:g_cbotts]
Sent: Monday, October 19, 1998 8:39 PM
To: gmcmotorhome
Subject: GMC: finding water leaks in dry weather

One method is to pressurize the coach with a very low pressure fan, wash
the outside of the coach down with high sudsing detergent and watch where
the leaks blow bubbles. Use a washing brush to investigate every seam. Air
will blow bubbles even where water will seep in. This is the same technique
in finding an air leak in an inner tube. It doesn't take much air pressure
to blow a soap bubble.
High volume low pressure fans are used to pressurize balloon buildings,
toys and advertizing. The pressure is low enough that you can walk in and
out of the "blown up building" without really feeling the pressure change.
Check the safety dump valve to make sure that pressure cannot be built up
inside and blow something out.
Chuck......I spoke to a Greyhound maintenance man years ago and he said
they've been finding leaks in their busses this way since the 1930's. Only
they do it the easy way. They just turn on the heater blower
motor........Jim Davis, 77 Coca Cola, Oregon

 

[dick kennedy]

Arch,

>From your description you could have the same problem that I had on my '75
PalBeach when I got it. Mine didn't move hardly any air then after checking
everything and much head scratching I finally figured out that the blower
was actually turning backwards.

The parts guy at Autozone didn't believe me until he put it on their tester
then he agreed it was indeed backwards and he had never heard of that
before. I bought a new motor and put it in then had proper air movement
although not nearly as much as I would like.

The motor had some sealant around it like someone had been in there trying
to fix it before but the motor looked original. The connectors on it can't
be plugged in backwards and everything is riveted so nobody could have had
it apart. My conclusion was that it must have come from the factory that
way; Somebody put the magnets in backward. Come to think of it I don't
remember if these are PM or field wound. If the dash AC was ever used all
they had was the ram air effect while going down the road.

Anyway this was so unexpected that I looked at it two or three times and
thought it was wrong before I really convinced myself. It's easy enough to
figure out but who would suspect a backwards blower in a 20 year old vehicle.

BTW I haven't done the gasket thing so could use any good info there. There
doesn't appear much that's easily accessible in there. What materials do you
use. I'm afraid I could make things worse if things start sticking together.

Dick

"75 PalmBeach

>Jim
>
>You mention the heater fan. My question is this. I could not get heater to
>go into the high speed mode------only had 3 speeds. Put in new high speed
>and solved that problem. But even at high speed there is not much air
>coming out of the vents. When I go outside there is a lot of air coming
>out of the square hole of the heater box. Yes, I have torn down the black
>box and replaced the foam gaskets. I am getting more air flow out of
>the square hole than I am on the interior--------any Ideas? TIA
>
>Take Care
>Arch 76GB IL
>
>
>In a message dated 10/20/98 9:54:25 PM Central Daylight Time,

>
>> Chuck......I spoke to a Greyhound maintenance man years ago and he said
>> they've been finding leaks in their busses this way since the 1930's. Only
>> they do it the easy way. They just turn on the heater blower
>> motor........Jim Davis, 77 Coca Cola, Oregon
>>
>
>