syncro fuel filler pipe leak

[hotpod]

i was just checking for play in my gear linkage on the camper and could smell petrol. it seemed to be coming from the off side of the engine bay so i assumed i had a fuel injection leak ( tank had just been filled by the way as i had to drive to glastonbury for a wedding)
engine lid off....no sign of any leak from the engine. the fuel was coming in from the wheel arch.
damn filler pipe has sprung a leak where it has trapped 20 years of road dirt between it and the chassis.
i have searched the forums and can find plenty of references to this but cant find info on a fix.
anyone done it?
how does the steel pipe connect to the tank, and can it be done with the tank in situ?
if not, is there a temporary fix while i summon the energy to take the a*** end out of the camper on a dirt floor with no ramp or pit.
ANY advice very welcome.

my solution for the journey by the way was to siphon 2/3rds of the tank out and put 20l at a time in for the duration of the trip and make sure i parked with the filler cap at the highest point. not a good long term solution though.

[syncropaddy]

Common problem this and always it happens when you've brimmed the tank! The steel filler pipe is pushed into a rubber grommet on the tank and seals this way. The pipe is then attached to the body closer to the filler cap. Take the pipe out, clean it and the rubber grommet, apply some fuel resistant sealer and reassemble. Take the wheel off as it will be easier!

[syncrosimon]

There is a 10mm nut holding the filler pipe onto a stud through to behind the airbox which is easily missed under crud.
You can see the bracket for it on the pipe.

[hotpod]

wicked! thanks chaps. If i take out and clean the rubber grommet, do i reassemble it dry or is there some ideal product for use with petrol and rubber?

[syncropaddy]

If its clean and dry and undamaged it should seal ok but try a smear of gasket sealant or something ....

[HarryMann]

Some do it dry, but lube like red rubber grease, or vaseline makes it a lot easier!

It sounds like it has corroded as you say... usually in bottomside (out of view) quite near that tag bracket, up against the inner flitch and chassis top

Common- its mud stuck between pipe and flitch panel.. years > wet > perforation corrosion

Those seals into the tank are still available I think

You should also check the bottom filler plate of the rear chassis in that region too... and check inside the air box floor, that water coming in down the snorkel inlet can escape directly without flowing down into the chassis below (should all be in the Wiki (somewhere)

https://club8090.co.uk/wiki/Ar ... norkel_box

[hotpod]

i just did it with vaseline. easy.
cant find anyone selling a replacement filler pipe. ive got a mate who can do all the bends in stainless but he would need a pipe to borrow for a while which would put the camper out of action. i have tig'd a patch on mine and cleaned it up as a temporary measure till i do an a*** end overhaul in the new year when work goes a bit quiet.
i measure the ends of the filler pipe at 40mm for the tank end, and 42mm at the filler end. it is all slimmer in the middle but i think that is just down to how it is made. i think that the tank end is the more critical measurement. the bends are all horzontal except the last one at the filler end. should be fairly straight forward apart from the swaged bit on the filler end for the hose clamp to sit behind.

has anyone got a knackered one i can have/buy to copy?

i had a look in the snorkel box too and its in a very similar condition to the one on the wiki with rust just starting around the weld of the filler tube tube.. i can only assume that the hole into the chassis is where they are meant to drain? they must have designed it to go somewhere.

[Aidan]

I have lent one to Baxter to have copied, email him and ask if when they will be available

[hotpod]

that sounds much easier. thanks.

[HarryMann]

i had a look in the snorkel box too and its in a very similar condition to the one on the wiki with rust just starting around the weld of the filler tube tube.. i can only assume that the hole into the chassis is where they are meant to drain? they must have designed it to go somewhere.

That'll be mine... (yellow?)

they must have designed it to go somewhere.

Nope, that's why, IMO, if you look here now in the Wiki, Areas that rust, you will see this:



Pretty convinced that's due to water ingress mainly from dripping down from the snorkel box...

A fix (for both rear side boxes) is suggested in the link here

20 years of dripping in from the vent down the snorkel housing, onto the box floor, down that (provided) hole but then sitting in the chassis... which needed a downward swaged decent size drain in the centre area of what is a big (larger than shown) destroyed area of the capping plate.

===========

Another area you might say

they must have designed it to go somewhere.

are the outside sections of the rear cross-member.

See here



I believe that if they'd made the large drain hole as I have (in replacement part), swaging it downwards/outwards instead of upwards and inwards, then this heavy 2mm section wouldn't rust away so badly, due retained water (and silt); mine was very thin and showed perforation after heavy twist-knot brushing, hence a 4" repair section. The inner face of the jacking point frame was also pitted and thinned, due constant damp/moisture that obviously could not drain away.

=======

A third place would be the Syncro fuel tank forward standoff bracket lower flange (containing the forward fuel-tank strap anchor bolts). Its lower edge and sides are gas-welded to the back of the cross-member (at the top edge), where it meets the engine hump and floor flange (3 layers)..

A very naughty area - gas weld areas if not very carefully treated in production can be bad corrosion sites (e.g. outer trailing arm mounts/rear jacking frames, despite 5mm thickness (see abov link for a shocking exmple!)

====

A fourth that doesn't drain is the plate under the B-pillar, up inside the front jacking point frame... a goodly sized hole in that, or a swaged drain at its inside edge (it slopes) might prevent a lot of trouble with the lower sill fwd. floor rusting away.

====

PS. Unless a hole is situated perfectly (through study of the water pooling & flow) AND it is heavily chamfered or swaged outwards/downwards, it may not be as effective as imagined

NB. The vehcile can be parked at different angles and may not get driven/shaken up or exposed to drying conditions for months on end...
Cheers

[manxman]

has anyone got a knackered one i can have/buy to copy?
.

I've got a half decent one of a single cab you can borrow, not sure if there all the same.

syncrospares?

[Aidan]

vans and pickups are different - filler in different place
as are tanks which are also petrol diesel specific
I have a couple of good used ones, one of each type for van, tang upwards and tang downwards, as stated one is at Baxters

[hotpod]

well my tig'd patch seems to have done the trick. not the merest hint of a leak on a full tank.

i might not have tried it if i didnt have a scrap stainless pipe bend to make a very snug fitting patch.




not a perfect weld. a more thorough clean up would have helped enormously but i didnt want to lose any thickness to grinding. maybe pickling paste.



i wasnt sure what to do with the sheared off bolt which holds the pipe on. it drilled out from the engine bay easily so i used a trick which has worked many times before. what would i do without araldite rapid?? plenty strong enough if you give it enough surface area and doesnt look too horrid.


and thanks to all the people who suggested vaseline. that was the key to an easy installation. it was much easier to refit than it was to remove.


and i didnt underseal till i had checked it for leaks.


i am not sugesting that this is a good permanent fix. i want a new stainless one but it did mean that my weekend plans for the beer festival at botallack werent scuppered. i love camping. even with a hangover!

i am wondering about a slight redesign though which would perhaps bracket it away from the engine bay wall and the chassis to stop crud getting trapped in there.
any thoughts?

[Aidan]

nice job, the rest of the pipe will probably go first
re redesign, it is already clearanced to allow the damper to pass so not much scope for moving it out wards really, could reduce diameter, but in reality they seem to last pretty well as long as you don't leave that area full of crud and road salt for long periods; it's usually vans that have been hammered and neglected or parked up for long periods at angles that suffer from that corrosion - mostly they seem to fail where the tang is welded/brazed on, especially the earlier version where the tang goes down onto the chassis rail rather than the later one which goes up as yours does - so VW have redisigned it once already

[hotpod]

OK. so it is just a good place to be checking every time you give it a wash.
TAKE NOTE EVERYONE WHO HASN'T ALREADY HAD THIS PROBLEM. (but be careful cleaning the crud off the pipe, it might be all thats keeping the petrol in!)