Herald petrol tank sender unit and seal

[Colin Lindsay]

I'm not happy with the seal on the sender unit for my 13/60 tank. I'm using both a new seal and a new locking ring, but it seems that before I fully rotate it into what I consider is the proper place it springs out again. I've 'sort of' managed to get it to stay put but am worried there's a smell of fuel - I put a pint in to check the fibre seal on the drain tap - and if the fuel fills up to sender level I suspect it will leak. Any thoughts on achieving a good seal?

[Gary Flinn]

Colin

I can remember having issues when I fitted a new Sender Unit and Seal on my Vitesse tank during it's rebuild.

I think I had to tweak slightly inwards carefully with a hammer and a block of wood the 3 retaining lugs on the circular tank opening so the lock ring was a tighter fit.

I wasn't convinced it would seal at first but it worked and held the contents of a full tank in place

I'm sure the new seal I got was rubber though which may have helped, it wasn't the fibre/gasket material type

(I much prefer the earlier type with the 6 screws)

Can you post any photo's? 

Gary

 

[dougbgt6]

Colin,

Yes I also had issues with the locking ring, on my GT6 tank. Having taken the sender unit off to examine the interior of the tank I realised a new sealing ring was required. What a performance! Much levering with the big screwdriver and hammering with the tiny hammer to get the locking ring to lock in effectively with the new fatter sealing ring.

Doug

[Pete Lewis]

replacement rubber rings and the 3 prong bayonet ring ive always found are the usual  aftermarket rubbish 

check the seal as if its chink fake it will leak and swell up quickly 

hey ho    in the day  there was a special tool for turning the ring but no idea where they are nowadays 

pete

[Colin Lindsay]

It's a new rubber seal, seemingly no longer available from some suppliers (Paddocks have it tho) but just to confirm - is it: the sender goes in THEN the seal and the the locking ring, or is it seal first THEN sender? Can't find any exploded diagrams of it, they're all the early 6-screw type where the cork ring goes first then the sender is screwed on top. 

 

[dougbgt6]

logic says sealer, sender, locking ring, surely?

Doug

[Jeffds1360]

Yes, I seem to remember, rubber ring first and then the sender unit, then lock ring.

I've never been able to afford to fill the tank, but 1/4 full and no leaks, even uphill 

[Pete Lewis]

definitley  seal    float   lock ring

pete

[Colin Lindsay]

The problem seems to be that before the locking ring is fully locked - at least to a point with which I'm happy - it lifts out of the tank aperture again. I'm not sure how well it will seal, and the only way to find out is to fill it... then the leak ruins my boot floor soundproofing again...

 

[Pete Lewis]

its obviouslt pretty imprtand all 3 lugs engage in the rim 

if it jumps out there is a size issue or the rim is  or needs some extra distortion so the ring is well located in the rim 

if the pair make a sloppy fit  theres a problem 

Pete

 

[Gary Flinn]

On 13/02/2023 at 12:28, Colin Lindsay said:

The problem seems to be that before the locking ring is fully locked - at least to a point with which I'm happy - it lifts out of the tank aperture again. I'm not sure how well it will seal, and the only way to find out is to fill it... then the leak ruins my boot floor soundproofing again...

 

Colin

It looks like the retaining flange in your tank is distorted, maybe the senders been replaced a couple of times in the past and a PO's been a bit to heavy handed when replacing the lock-ring?

You may need to carefully fettle it back into a better shape with a hammer and a block of wood (Especially the 3 curved sections that the retaining ring locates on) so when you insert the seal/sender/retaining ring the retainer is a better/tighter fit and won't pop out.

There's none of this with the earlier 6 screw senders, I wonder why they decided to change it.

Gary   

 

[Colin Lindsay]

This isn't the tank that was removed, which sprung a leak, but is a spare that still had the drain neck fitted. I had reckoned that it would be sensible to recondition the 'dry' tank which had been sitting for some years, but the locking ring seems to be causing problems. I'll compare with the old one for size and possible distortion. I do have earlier tanks but they're smaller - not that that really matters - and screw-in sender units but would rather persevere with this one.

[Pete Lewis]

why change  its a much quicker and simpler job on theassy line to twist a bayonet ring than fit and tighten 6 screws 

 

you can make a 6 hole sender fit a bayonet ring tank by triming the sender disc to fit 

as had to do this on the Vit6 witha new tank .

and you will find a 6 hole sender and baynet sender are often not compatible depends on bi metal or moving iron gauges 

you cant mix and match  only No match .