[A/S] Thetford Waste valve rebuild

[Mike Keith <mkeith@xxxxxxxxxx>]

I just finished rebuilding both valves on my 75 Argosy rear bath and 
thought I'd share the experience.

Tools needed:

Drill with 1/8" bit  (for drilling out any rivets that need to be removed
#2 Phillips screwdriver
Stubby #2 Phillips screwdriver
#3 or #4 Phillips screwdriver.
medium common screwdriver
pliers
Pop rivets and tool

Parts needed
2 Thetford valve repair kits

1.  The first step is gaining access to the valves, in my case I had to 
drop the belly pan for about three feet forward starting at the trunk.

2.  Next, starting with the gray water valve loosen the band clamp on the 
out let of the gray tank.  This allows the plastic pipe that goes into the 
tank to rotate which you'll need to do later.

3.  Disconnect the pull rod handle or extension from the pull rod.  Remove 
all the small screws in the body of the valve except the two where the pull 
rod goes in.

4.  At this point the valve will separate into two halves.  If your black 
water valve is screwed into the black tank and the pipes join with a small 
rubber slip connection, stop on this valve and proceed to the black valve.

**********  WARNING *****************
THE BLACK WATER SYSTEM CONTAINS THINGS REALLY, REALLY BAD TO YOUR HEALTH.
Rinse the black tank several time and use some soap to help loosen the bad 
stuff from the tank.  I used a cup of bleach and filled the tank with hot 
water and let it set for a couple of hours. Drain the tank.

5.  Disconnect the pull rod handle or extension from the pull rod. Remove 
the 4 large screws holding the valve to the bottom of the tank and loosen 
the band clamps on the rubber slip joint.  Working from the uphill side, 
slide the valve and waste line from the tank and remove from the trailer.

6. Remove all the small screws except the two by the pull rod.  separate 
the valve halves and clean with a strong bleach water solution.

7.  Remove and discard all rubber pieces.  Install new rubber parts and 
reassemble.

8.  Reinstall the black valve reversing the instructions above.

9.  Remove old rubber parts from the gray valve and install new rubber parts.

10.  Reassemble the gray valve and install both pull rod extensions.

11.  Tighten all the clamp loosened and the check them again.

12.  Fill both waste tanks with clear water and check for leaks, if every 
thing worked there are no leaks.

13.  Raise the  Belly pan back into place and rivet it up.


HTH

Mike