Welcome to Manins' truck camper project

Toilet Changes

TT30 comes fitted with a horrid Thetford C-200 Cassette toilet. It is connected to the water supply system and flushing is done by means of a 12 V magnetic valve.

If used with chemicals, every time the slide is opened these systems give off an odour that is really unpleasant. But not as unpleasant as when no chemicals are used.

We have had great success using generic Napisan or 'laundry soaker', based on sodium percarbonate, from Woolworths. This breaks down to hydrogen peroxide and salt, and the peroxide oxygenates the liquids and solids, breaking them down aerobically.

Even so, each time the slide is opened there is still an odour. The answer is a SOG system! The SOG 12V ventilation system works on the basis that as soon as the slide is opened on the toilet the fan is activated. Fresh air is sucked in through the opening and acts as a seal to prevent gases from rising up from the cassette. The fan switches off as soon as the slide is closed.

A SOG kit Type B (see here for kit contents) is required for the C-200. These are ridiculously expensive, but I obtained a Type F kit (for the C-250) for a very low price so set about installation of a modified version. First off I bought from Aussietraveller the connector that replaces the overpressure valve. This cost about half as much as the whole kit cost me! Then I decided I would not vent the exhaust air through the filter in the toilet access door, but instead through the floor. A SOG II filter is designed for that purpose but that would mean replacing the fan with an axial type and the filter cartridge is just too big for the space available.

Careful measuring established that a length of 32 mm dia pressure pipe could run down the right hand side of the cassette compartment through the floor and into the filter holder that normally mounts on the door. The filter holder would be upside down under the floor. The fan would fit in a bored out coupler at the top of the pipe and would be connected to the cassette via the flexible hose in the usual manner.


Waste slug from boring a 32 mm dia. hole through the floor of the camper for the SOG vent. It is 46 mm thick.


The hole for the vent pipe is on the edge of the cassette compartment.

Boring through the cassette compartment and camper floor was rather traumatic.

These photos show the completed installation. The fan sits in the coupler at the top of the vertical pipe, and the flexible hose joins to the green connector on the cassette.


The fan body is an easy press fit into the coupler on top of the pipe.


The green connector on the cassette can be just seen.

The tricky bit of the installation was working out where the microswitch goes. This controls the fan, which is on when the slider is open and otherwise off.


The switch was moved on its angle bracket to place it in the correct position. The photo gives a bit of an idea of the final location of the microswitch.

Under the camper, the filter holder with pipe glued in position; the activated carbon filter in place; the view from the rear of the filter holder; and finally, the cassette back in the compartment.

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In Use


The carbon filter is a bit of a joke. Smells are outside (an improvement) but they are certainly evident. Plenty of use of the generic Napisan should help.

An aquarium filter medium is being trialled. The filter is 46 x 25 x 1 cm. Cut up and doubled in thickness gives four filters for the SOG at a much lower price than the original.