Leaking fuel tankSAFETY CHECK......UPDATE

[I.Mupferit]

The screws holding the top plate of the fuel gauge sender unit to be precise.

 

I filled the 7 up at a garage about 1/2 mile away on my way home today then put the car away and carried on with a DIY project I'm doing to gain Brownie points and when I went back into the garage about 2 hours later it reeked of petrol

 

I went round the back of the car, had a look underneath and saw a large wet patch on the carpet, right under the tank. I had a look up under the tank and it was running down the front so took the floor out to discover the plate on top, filled with petrol that was still leaking out. I dried it off and nipped the screws up but was alarmed to see the petrol continuing to come out from under every single screw head around the fibre washers ❗

 

Obviously the tank was a little too full but these screws really shouldn't leak as they do ☹️ I didn't have time today but tomorrow I will take all the screws out and fit new fibre washers plus seal them with fuel resistant sealer but bearing in mind this is less than 1 year old, I would urge everybody to check these screws especially if you have just filled the tank, and seal them if necessary. I have brimmed the tank before but usually whilst out on a blat so the tank is not normally full by the time I put the car away, thus the problem is not evident.

 

I have now informed Simon Lambert at CC about my leak since reading RobinW's thread and realising this is a recently discovered manufacturing problem with the wrong rivnuts fitted to some tanks. I am awaiting his response but in the meantime, felt it was worth making everybody aware of this so that they can check their own tanks or, at the very least, don't overfill the tank.

 

It is only apparent with the tank brimmed full and the car standing idle but the rate the petrol leaks out is frightening so please do check your cars as soon as possible. Don't simply tighten the screws as that will cause distortion under the plate and just cause the gasket to leak.

 

If you take just one screw out, it is very easy to tell if the rivnut is blind, as it should be, by poking a piece of wire or similar into the exposed hole. If the wire hits a stop around 15mm down then yours is ok. If it just goes right on through, then seal the screw threads and under the heads with a fuel resistant sealant.

 

Brent

 

2.3 DURATEC SV Reassuringly Expensive

R 417.39 😬

 

 

 

 

 

Edited by - Brent Chiswick on 9 Jun 2006 09:26:12

[Manxseven]

Brent,

 

Did you see this thread from Robin W.

here

Page 2, 17:13 post.

 

 

Caterham Fireblade here

 

Edited by - Manxseven on 18 Mar 2006 22:32:19

[Big Brother]

Brent,

Mine did the same a while ago.

I filled it up at the garage next to the Phoenix, went in to pay and came out to see a puddle of petrol under the car

I replaced the cork gasket under the sender and lightly nipped up the fixing screws after smearing them with silicone sealer.

 

Touch wood its still holding together

 

Steve

 

 

SE7EN-UP!

Incorporating the Caterham Links Database

[I.Mupferit]

Definitely not the gasket on mine Steve. Thanks for that Manxseven, I hadn't seen that thread so sounds like a call to CC will be necessary on Monday.

 

Btw Steve, if silicone sealant comes into contact with petrol it turns into a gooey mess which is known in the trade as 'Gorilla snot'. 😬

 

Brent

 

2.3 DURATEC SV Reassuringly Expensive

R 417.39 😬

[Big Brother]

Sorry Brent, I meant gasket sealer - I think it was Hermatite or similar.

 

Steve

 

 

SE7EN-UP!

Incorporating the Caterham Links Database

[Bozz]

Brent

 

BTW how's the oil pressure?

 

Bozz

 

Sorry, but my karma just ran over your dogma

My Chocolate Orange here

[I.Mupferit]

Not had a chance to get it good and hot to try it yet Bozz.

 

Brent

 

2.3 DURATEC SV Reassuringly Expensive

R 417.39 😬

[Normans_Ghost]

Mine has a rubber gasket on the sender unit. If you overtighten the screws it will compress and squeeze the gasket out which will then leak.

 

Norman Verona, 1989 BDR 220bhp, Reg: B16BDR, Mem No 2166, the full story here

You and your seven to The French Blatting Company Limited

[I.Mupferit]

The gasket is fine Norm, it seems to be the open rivnuts wrongly fitted instead of the normal blind jobbies that are the culprit. It seems CC have discovered there were a batch of tanks made with the wrong rivnuts as RobinW's thread.

 

Brent

 

2.3 DURATEC SV Reassuringly Expensive

R 417.39 😬

[RobinW]

I'd sussed the fact that fuel was leaking past the screws so I tightened them up and low and behold, it was then leaking past the screws and the gasket. Like Norman says, you can't overtighten them. I was just contemplating Hermetite, when CC called me to explain the problem.

[I.Mupferit]

I've now sealed the screw threads and under the screw heads with blue Hylomar, topped up the tank again and it appears to be fine so I may just go with that rather than faff about getting the tank changed although I will register the problem with Simon Lambert in case of future leaks in that area.

 

I'm aware of the danger of overtighening the screws so hadn't overdone it.

 

Brent

 

2.3 DURATEC SV Reassuringly Expensive

R 417.39 😬

 

Edited by - Brent Chiswick on 19 Mar 2006 12:20:04

[paul jacobs]

I've been following Robins fuel tank leaking probs. with interest, as you might have noticed from his thread Brent. Mine could be the same too, but I haven't had a chance to check yet. it sounds to me, that because of the extreme fire hazard, this is a classic case for a manufacturers recall. I wonder if it will happen though? I wonder how many other tanks have been made with open rivnuts?

 

Paul J. Hard work never killed anyone ........ but why take the chance! [Except building up my new CSR kit, suspension finished, wings on, engine/gearbox in, currently connecting and filling.]

[I.Mupferit]

Paul, I agree it should be the subject of a safety recall. Do check yours as I was surprised at just how fast the fuel was coming out so if the tank is full, it is a definite fire hazard.

 

I imagine the CSR uses the same tank as the SV but don't know if this manufacturing oversight only affects these or the S3 chassis as well. In any case, if I had an S3, I would be checking that as well ❗

 

As you haven't finished your car yet, it would be relatively easy for CC to swap it out at this stage if it has the same fault. As it was quite an easy job to effect a seal on mine, I have elected to leave it as is for the time being.

 

Brent

 

2.3 DURATEC SV Reassuringly Expensive

R 417.39 😬

 

Edited by - Brent Chiswick on 20 Mar 2006 10:25:27

[Graham Perry]

Just done mine. Sealed with Wurth RTV.

[I.Mupferit]

I have received a reply from Simon Lambert regarding this issue as follows:-

 

".........Whilst the fuel pump rivnuts should be blind (including those on the top mounting CSR pump), the rivnuts that hold the level sender in have always been of the traditional open type and have never created an issue"

 

Now, whilst I have the utmost respect for Simon and, indeed, he may well be right about these particular rivnuts having always been the open type I still believe there are some issues to address here.

 

1) Like RobinW's car mine leaked around screws, which were nominally sealed with fibre washers, immediately after topping up the tank. Had the fuel level been just slightly lower then probably neither he nor I would be aware of any potential problem.........maybe until a fire had actually started at some point in the future.

 

2) The CSR tank is, obviously, different to the SV but if the pump mounting is in the top of the tank and it is deemed necessary to use blind rivnuts to prevent leaks, then surely, the top plate of the sender should also require blind rivnuts for the same reason.

 

3) Just because these unsealed screws hadn't created any issues previously that CC were aware of, that doesn't necessarily mean there is not a problem and that it doesn't need addressing. There are thousands of instances where problems only come to light after the product has been in use for many years and under specific circumstances.

 

As I said above, I was alarmed and surprised at just how fast the fuel was leaking out from around these screws and simply tightening them is not a solution since you will only succeed in distorting the mating flange thus causing the fuel to leak from both the gasket and the screws, exactly as Robin discovered.

 

Our options are, as I see it :-

Do NOT fill the tank right up to the brim. Try and leave an air gap at the top of the tank, or preferably........seal the screw threads and under the screw heads with a non setting fuel resistant sealant such as blue Hylomar or similar as I (and Graham) have done.

 

I have suggested to Simon that CC might consider fitting blind rivets to all these tanks in future as I don't believe just fibre washers on their own are sufficient but, of course, this is entirely up to Caterham Cars. In the meantime, I would urge everybody to take heed of this problem and address it as they see fit.

 

 

 

 

Brent

 

2.3 DURATEC SV Reassuringly Expensive

R 417.39 😬

 

 

 

Edited by - Brent Chiswick on 22 Mar 2006 09:14:59

[paul jacobs]

There are also other issues if the car is involved in an accident. If the car is on its' side or upside down [heaven forbid ] one doesn't need much imagination to realise what could happen to any leaking fuel...............

[I.Mupferit]

Precisely!

 

I believe blind rivnuts should be fitted as a matter of course to all such flanged joints on the tank. It can't even be argued against on the grounds of cost since we are talking about 6 rivnuts and therefore a total of an infinitesimally small fraction of a penny.

 

Brent

 

2.3 DURATEC SV Reassuringly Expensive

R 417.39 😬

[Dickie Normuss]

My S3 tank started leaking about 2 months ago, new gasket at home but not got around to fitting it yet. Do Halfrauds have the blue Hylomar?

 

Seek forgiveness, not permission.

Rules are for the interpretation of wise men and the obedience of fools.

[I.Mupferit]

They used to and may still do but failing that any fuel proof, non setting sealant will do the job.

 

Brent

 

2.3 DURATEC SV Reassuringly Expensive

R 417.39 😬

[RobinW]

As it turns out my tank did have the correct rivnuts fitted (the CSR has a combined pump/sender unit on th etop of the tank). Nevertheless, CC recognised that the tank was leaking and fitted a new one. They couldn't explain what was causing the leak, but reported that everything was OK.

 

I picked the car up last Friday and on Sunday filed it up to the brim and took it for what might best be described as an 'enthusiastic' blat. Low and behold, it's still leaking . After about 30 miles of said blatting, the fuel has dropped to a level where the problem goes away again.

 

I'm going to try the sealant solution. Brent, where can I get the stuff that you have used?

[I.Mupferit]

Robin, I'm pretty sure I originally bought the blue Hylomar in Halfords some while ago but as I said above, any non hardening, petrol resistant gasket sealant will do the job.

 

I've used the Hylomar on cars for more years than I care to remember and always found it very good so tend to stick with what I know works but I'm sure there are more modern sealants available that are as good if not better.

[I.Mupferit]

Btw, is it still leaking around the fibre washers under the screw heads?

[RobinW]

To be honest I don't know where it's leaking from yet Brent. I haven't had the opportunity to lift the floor. But there was a very strong smell of petrol once I got the full tank sloshing around.

 

At least this time it wasn't dripping onto the garage floor. Presumably because I burned off a lot of the fuel before parking her up for the evening.

[I.Mupferit]

You've hit the nail on the head there when you say you had burnt off sufficient fuel for it not to leak out over the floor.

 

As I said at the start of this thread, I don't ever before recall topping up the tank and then immediately putting the car away so the problem hadn't been apparent but I wouldn't mind betting this area of potential leakage affects an awful lot of 7's which the owners are blissfully unaware of.

 

Brent

 

2.3 DURATEC SV Reassuringly Expensive

R 417.39 😬

[Goldsie32]

☹️ O my, I have a 1991 seven, as I was about to approach my garage I could smell petrol, lucky I do not smoke ☹️ Bang would of gone my 7 and me,there was a pool of petrol under the car. As the car was in the garage leaking for about 3 days. VAPOUR WOW!!. On inspection taking tank out, I found where the tank was seated between metal brackets & ali tank; there was no protection so the ali reacted with the metal turning to pin holes and flaking of tank.Also on top of the tank I found petrol stains where the tank had been leaking as Brent Chiswick had reported. Therefore this must be a long standing problem!!