- Oct 22, 2025
- 1
- 0
- Funster No
- 115,793
- MH
- T4 A/S Trophy
Hi all,
Looking for a bit of wisdom from anyone familiar with Thetford C3 toilets fitted in early-90s VW T4 Trophy (or similar coachbuilt) conversions.
Long story short: the flush wasn’t working - the mechanism moved fine, but no water reached the bowl. The manual that came with my van suggests the toilet is linked to the main water tank, so I initially went hunting for a blocked or sludged pipe.
Turns out mine’s the manual-flush version (no electric pump) with the built-in flush tank under the bellows - not the later C200 with a separate filler.
I’ve checked high and low and can’t locate an external filler neck or cap anywhere on the van - looks like it was deleted or never installed. I’ve also found the rubber drain hose and bung (in the cassette compartment), which drains the flush tank perfectly.
The bellows pump now works again after I dismantled the flush mechanism and manually filled the integrated tank with water via the flush housing, but I’m wondering:
Am I always going to have to refill it this way, or am I missing something painfully obvious?
- Was this model originally meant to be filled externally, or did some Trophy builds use a hidden internal fill setup? (Which I evidently haven't been able to find)
- Has anyone re-fitted a proper Thetford filler-neck / cap kit to restore external filling - and if so, where did you route it?
I’ve attached a few pics showing the tank cavity etc (please excuse the grime — first we fix, then we clean!)
Appreciate any insight from those who’ve worked with these integrated tanks or refitted older C3s - I’d much rather keep the original kit alive than rip it out for something modern.
Thanks,
Sam
1994 VW T4 Trophy | 2.4D
Looking for a bit of wisdom from anyone familiar with Thetford C3 toilets fitted in early-90s VW T4 Trophy (or similar coachbuilt) conversions.
Long story short: the flush wasn’t working - the mechanism moved fine, but no water reached the bowl. The manual that came with my van suggests the toilet is linked to the main water tank, so I initially went hunting for a blocked or sludged pipe.
Turns out mine’s the manual-flush version (no electric pump) with the built-in flush tank under the bellows - not the later C200 with a separate filler.
I’ve checked high and low and can’t locate an external filler neck or cap anywhere on the van - looks like it was deleted or never installed. I’ve also found the rubber drain hose and bung (in the cassette compartment), which drains the flush tank perfectly.
The bellows pump now works again after I dismantled the flush mechanism and manually filled the integrated tank with water via the flush housing, but I’m wondering:
Am I always going to have to refill it this way, or am I missing something painfully obvious?
- Was this model originally meant to be filled externally, or did some Trophy builds use a hidden internal fill setup? (Which I evidently haven't been able to find)
- Has anyone re-fitted a proper Thetford filler-neck / cap kit to restore external filling - and if so, where did you route it?
I’ve attached a few pics showing the tank cavity etc (please excuse the grime — first we fix, then we clean!)
Appreciate any insight from those who’ve worked with these integrated tanks or refitted older C3s - I’d much rather keep the original kit alive than rip it out for something modern.
Thanks,
Sam
1994 VW T4 Trophy | 2.4D