Morris Minor Owners Club

Well, today was my most eventful day of Moggie ownership. Since I got the car in November, there's been a strong petrol smell after filling up, and a little pool around the sender unit suggested that the paper gasket was leaking (I have a Traveller with the larger 6.5 gallon tank).

I spent ages researching threads here and elsewhere, and decided to replace the gasket with an Ethanol-proof one; I ordered it from Moss Europe as I didn't want to take a chance on something from eBay or Amazon. I bought this one for £850, plus VAT and P&P: https://www.moss-europe.co.uk/gasket-se ... soc=591154

I fitted it this afternoon, with a smear of Hylomar blue on the gasket and screw threads, as that seemed to be a popular sealant and petrol proof. I made sure the screws weren't too tight as I'd read that might cause the gasket to fail.

Drove down to the petrol station, filled up with 25 litres, and immediately petrol started gushing out from underneath the car. I lifted the floorboards and immediately saw that the gasket was hanging out from around the sender unit and petrol was welling up, spilling over the sides of the tank and gushing out of the bottom of the car.

As the sender unit on the 6.5 gallon tank is recessed, there was nothing I could do except to wait for the petrol to drain low enough for me to refit the old paper gasket. I mopped up the residue, waited until the fumes had cleared, checked the gasket wasn't leaking and came home.

It was a bit terrifying, to be honest; the petrol station attendants weren't much help and I was really worried that a stray spark might light the whole lot up. I'm furious that I paid a premium to a reputable dealer for a fuel proof gasket, and ended up in precisely the situation I wanted to avoid.

I'm going down to a local motor factors tomorrow morning, in the hope that they have cork gasket which will actually do the job. Will be contacting Moss on Monday, if not trading standards.

Seb

Looks seriously faulty , on a more humerous note ( if there is one with a problem like this ) for £850 I would have expected quality !!!!!!

Shropshiremoggie wrote: ↑Sat Mar 02, 2019 8:42 pm Looks seriously faulty , on a more humerous note ( if there is one with a problem like this ) for £850 I would have expected quality !!!!!!

Ha ha! That's made me smile for the first time today! Whoops - £8.50 of course....

Just a thought, If the gasket is made from a type of rubber, maybe the added sealant caused it to slide, resulting in the gasket being squeezed out.

I used Hylomar Blue, which is really sticky- though it doesn't set solid. There's no way the gasket would have shifted as it's so adhesive, and I checked the gasket's position after I'd tightened the screws. It's like the petrol made the rubber actually soften and drip.

If you read the data sheets for both Viton and Hylomar they state that both are suitable for use with Benzene and petroleum.

When using Hylormar the Acetate in the Hylomar must be allowed to evaporate off before fixing the gasket in place.

Did you allow the acetate to evaporate off before fixing?

Acetate Solvent has a severe effect on Viton.

70mm OD, 50mm ID and bolt pattern is 6 x 60mm. Cheap cork gasket material with no sealant although Cornflake packet + Hylomar might be quite good.

Here's my drawing of that gasket. It is the same as the MG TD/TF gasket. I would not recommend Hylomar. Permatex aviation sealant #2 or Reinzoplast seem to be the better choice. Ignore the lower gasket for Moggy use.
Regards
Declan

Better version than mine, Declan. Accuracy to the nearest .01mm. Very Germanic!

Rob,
It is actually 2-3/8" (60.325mm) but the CAD is set to 2 figures after the decimal point so it was rounded off to PCD 60.33mm.
Not Germanic,-imperial.
Regards
Declan

Declan

The two sealants you recommend above do not appear to contain Acetate but Permetex does contain a form of solvent.

https://441py33rout1ptjxn2lupv31-wpengi ... /80011.pdf

Reinzoplast is solvent free.

I do not appear to be able to download a copy the data sheet for Reinzoplast but it is on the web if details are wanted..



Phil

Phil,
On the technical data sheet for the Permatex there is no mention of Acetate.
https://www.permatex.com/products/gaske ... 2-sealant/
Highly recommended on the T-Series forums.
I am not sure about Reinzoplast as the data sheet does not specify the exact chemical composition.
http://datenblatt.reinz.de/web1/en/prod ... pdf?bct=21
I have been using Reinzoplast for years with great success. It even looks the same as Hylomar-who knows???
Regards
Declan

Declan
Thank you for the above.

Ketone also has a degrading effect on Viton so sealants containing it should be avoided.

Phil

Phil,
Correct. It says on the data sheet:
Do not use Viton with acetone, esters, amines, organic acids, acetic acid, MEK, ethyl acetate, highly polar chemicals, etc.
https://www.calpaclab.com/viton-chemica ... ity-chart/
Regards
Declan

Thanks all for the advice, and particularly the dimensions of the gasket.

There was no datasheet included in the box of Hylomar Blue, and nothing included with the gasket either- just a clear polythene bag. I've read countless mentions of 'a smear of Hylomar' on gaskets and not once read that it contained solvents which might damage Viton or I would never have used it! Given the disastrous
consequences, I'd have hoped that one or other product might have contained a warning.

That said, the gasket was sat for a few minutes before I fitted it and there was no smell of solvent, so I would have thought that any solvent fumes would have evaporated before fitting.

Had to pop out in the night to check that it hadn't started leaking again; I couldn't get the thought of petrol pouring out of the car out of my head. All dry thankfully. Though I did notice that some wonderful person has scraped the paint right along the driver's side of the car, and put a dent in the rear wing. It never rains but it pours (and now it's raining...)

http://hylomar.com/warrick/wp-content/u ... ssue-8.pdf

Hylomar should not be applied directly to a Viton gasket/seal.

If you require to use Hylomar and a Viton gasket in this case the aperture for the fuel gauge transmitter Hylomar should be applied to the tank and the transmitter only (not the gasket) and then left for several minutes (I would suggest 15min) for the Acetate to evaporate off and then the three parts (tank, gasket and transmitter) can be assembled.

Only the lightest application of Hylomar should be applied.

When assembled the Viton seal should be checked for possible degrading.

Personally I would not use Hylomar with any product made with Viton.

Whatever product you use the product data sheet and the Control Of Substances Hazardous to Health (COSHH) data sheet should be consulted.
Most if not all of the information required is on the web.

£8:50 will buy you a 20cm x 20cm sheet of 1mm Viton rubber if you want to cut your own out (and enough for a dozen more), including postage from Ebay sellers. Doesn't require much precision so scissors and a hole punch would do.

Thanks Rob, thanks Phil,

Lesson learnt. I think I'll just get some of the 50p cork ones and keep a few spare; I checked the packaging of the gasket and the sealant and nowhere did either of them say that Hydromar Blue and Viton should not be put together- I went for that combo because other folk on forums seemed to have had success with it. I wouldn't have expected to have to look up datasheets online, I'd expect anything that serious to be put in the instructions on the packaging! Will triple check everything in future...

Seb

We are all guilty of assumption ( ie warnings should be given ) but its dangerous to assume anything these days .

RobThomas wrote: ↑Sun Mar 03, 2019 1:24 pm £8:50 will buy you a 20cm x 20cm sheet of 1mm Viton rubber if you want to cut your own out (and enough for a dozen more), including postage from Ebay sellers. Doesn't require much precision so scissors and a hole punch would do.

Rob,
You can only cut five from a 20x20cm sheet.
Regards
Declan