Fixing a VDO freshwater tank gauge - shock horror

[Finbar]

Overwinter I noticed my VDO Gauge for the forward water tank was showing half full, although it was empty. Had a look and the ceramic coated side of the capacitative sender was corroded under the rubber support. No problem, I thought, replace the sender. Shock horror, £330.00 see http://www.furneauxriddall.com/acatalog/VDO-Waste-Water-Level-Sender-N02240402.html.

The rods can be taken out of the cap for shortening. Anyone know if they can be repaired (Epoxy?) or replaced? Or failing that a source for a generic sender?

Resistive senders are by comparison reasonable, but will not work. I think I would take my chances rather than spend that much beer money on a water gauge

 

[pvb]

Had a look and the ceramic coated side of the capacitative sender was corroded under the rubber support.

Is the "rubber support" the bit which covers the bottom of the rods?

 

[rogerthebodger]

If the ceramic coated side of the capacitative sender is open to water the sender will not work and needs re waterproofing Clean it up by sanding and coat it with ceramic filled epoxy.

I also have capacitative sender but not VDO and when I shortened mine to fit my tank I had to seal it in the same way for the same reason.

 

[pvb]

I also have capacitative sender but not VDO and when I shortened mine to fit my tank I had to seal it in the same way for the same reason.

The VDO sender is designed so that the rods are shortened above the unit, in air, so as to maintain the integrity of the coating on the rods. Perhaps the OP's sender was wrongly shortened?

Certainly worth trying a repair rather than a £300+ replacement.

 

[rogerthebodger]

The VDO sender is designed so that the rods are shortened above the unit, in air, so as to maintain the integrity of the coating on the rods. Perhaps the OP's sender was wrongly shortened?

Certainly worth trying a repair rather than a £300+ replacement.

Yes I know that and you may be right on the incorrect shortening. Mine is different with a center insulated stainless steel rod inside a plastic tube with an uninsulated stainless steel rob wound around. the plastic tube.

In fact only one of the rods meed to be insulated so that no leakage current can pass between the rods.

 

[Finbar]

Many thanks for the helpful advice. The ceramic coating corroded under the centre rubber support, rather than the bottom end one. I will certainly sand down and reseal with epoxy. I take it the sanding dust is the ceramic powder which is added to the epoxy? I will post to report on progress.