Fuel Tank Sender Unit

[Motorhome-Les]

Hi All,

Does anyone have a close-up photo, of the top of a Mk3 or Mk4 fuel tank sender unit.
I'm trying to figure out if it's going to be easily possible to fit a dip-tube through the top flange of the sender unit, in order to create a fuel take-off to feed to a diesel heater in my camper.
I'm aware that some of the later models of sender units have a plastic capping, that can be simply cut to insert a dip-tube --- it would be great if the Mk3-4 had the same arrangement.
If not, then I'll just have to drill and fit a dip-tube, but it would be good to initally view the top of the sender unit without having to drop my own fuel tank. This is a job that I'm planning on doing when the warmer weather is here !!!

Many thanks in advance.

[Chug]

There is plenty of room to fit a dip tube(or three) in the top of the sender unit, its about 6 inches in diameter and only has two pipe connections and a socket/plug for the fuel gauge. If you still really need a picture I'll go out in the cold tomorrow and take one

[dumper]

A lot of the conversion companies use the drill the tank type on plastic tanks

[dochie]

I've been thinking of fitting a diesel heater to my Mk4 motorhome but is there any reason why you can't just put a T-piece between the pipe from the tank to the lift pump?

[Chug]

The reason for a separate dip tube is it sits higher than the usual fuel feed, so it won't run you out of fuel, you can 'T' into the fuel pipe just keep your eye on the fuel gauge if you use the heater a lot.

[dumper]

BT used to tee in on the mk 3&4 but as chug says the dip tube you can fit doesn’t go to the bottom my mk 6 and mk8 heater cut off at around a quarter of a tank I only started using a dip tube on my mk6 because they were tdcis with a pump in the tank if I was going to fit a heater to any thing with a mechanical pump for ease I’d tee in to the fuel linee.

[MinorMatt]

The mk3/early mk4 sender (round fuel cap) is quite a small diameter - prehaps 3"? The mk4 and mk5 ones (oval fuel cap) are quite a lot bigger ~6"

There would be space to put a stand pipe on both - vans with factory PTC heater (the later type sender only) had a stand pipe built in to the sender unit.

You can also drill and add a standpipe to the top of the tank, or Tee in to the fuel pipe between the sender and lift pump. If you engine doesn'tr have a lift pump you could probably also take the feed from the top of the fuel filter?