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Petrol leak

Posted: Sat Aug 29, 2020 6:18 pm
by jaguar&mg
A fine but powerful spray of petrol is coming out of the top (I think) of R. The petrol is running out even faster than usual!

Any ideas? Rather dangerous, I would have thought.

Re: Petrol leak

Posted: Sun Aug 30, 2020 12:24 am
by Glyn Ruck
Looking for an engine compartment fire. Keep an extinguisher close by. I have actually seen those AC fuel filter housings both crack & corrode through. Remove the entire filter assembly & remove the top screen above the glass bowl, clean & examine carefully. If no fault is found replace fibre washers at the banjo joint & seals on the glass housing. The way you have that filter configured with a folded element in it dirt will collect on the inside of the element. New units are available if necessary.

Good luck!

Fuel Filter.JPG
Fuel Filter.JPG (62.74 KiB) Viewed 2093 times
Fuel Filter1.JPG
Fuel Filter1.JPG (53.63 KiB) Viewed 2093 times
Fuel Banjo Bolt Fibre Washer.JPG
Fuel Banjo Bolt Fibre Washer.JPG (20.21 KiB) Viewed 2093 times

Re: Petrol leak

Posted: Sun Aug 30, 2020 11:39 am
by cass3958
Don't take chances with leaks. My biggest fear is a leak of fuel and an engine fire.

New gaskets are cheap so change them all as old gaskets can become brittle or hard. Old gaskets can hold a good seal until you undo the joint and then try and seal it again with the old gasket so change them.
Make sure when you fit the gaskets that they are centred up correctly. If not you can pinch them and the will leak.

Don't over tighten any of the threads as most of them are in aluminum housings.

Some fuel leaks are hard to find as the fuel evaporates before you can find where it is coming from and it can also travel downpipes a long way from the actual source. Sometimes you can smell a leak but cannot see it. I have some light blue paper kitchen towel which changes to a dark blue when it comes in contact with a liquid. I run this over the fuel pipes and joints on a regular basis to check for leaks.

I have a fire extinguisher in a bracket under my legs in the driver's seat. Quick and easy to get to. No good having one in the boot of the car. By the time you get out of the car, run to the boot to find it locked, found the correct key on the ignition key fob and got the boot open the front of the car would be a blaze.

Re: Petrol leak

Posted: Sun Aug 30, 2020 2:10 pm
by jaguar&mg
Thank you very much. This is, however, beyond my limited ability so I shall have to have the car transported to someone who can sort it. Driving it there is several risks too far!

Oh those costs will mount up!

Re: Petrol leak

Posted: Sun Aug 30, 2020 8:02 pm
by John Quilter
Glyn's second photo shows a paper filter element. From 1966 when I acquired my 3.8S there has never been a filter in this glass bowl. Never had any fuel system issues without one in all these years although once in a great while a small bit of sediment collects in the bottom of the bowl. Did all these AC fuel bowls always have a filter?

Re: Petrol leak

Posted: Sun Aug 30, 2020 8:10 pm
by John Quilter
And just now checking the factory parts manual, it shows no filter. Must have been something added in later production?

Re: Petrol leak

Posted: Mon Aug 31, 2020 2:45 am
by Glyn Ruck
You are correct: Brass screen was all that was fitted to cars up to 1968. Then followed the moulded resin insert known by Jag aficionados as the "burnt cake" filter in the glass bowl. The folded paper element was a newer introduction. Burnt cakes are hell to find these days. Most of us just use the paper filter. Helps with Viton tipped float bowl needle & seat contamination & float bowl overflow.

From the JCNA Mk2 Concours Judges guide. Same applies to S Type.

Filter.JPG
Filter.JPG (84.31 KiB) Viewed 2063 times

Like Rob I keep a fire extinguisher in the cabin close to hand. Friend lost a Mk2 he restored due to being too cheap to replace a buggered wiring harness.

Re: Petrol leak

Posted: Mon Aug 31, 2020 4:10 am
by Glyn Ruck
Filter2.JPG
Filter2.JPG (79.49 KiB) Viewed 2055 times

Re: Petrol leak

Posted: Mon Aug 31, 2020 10:03 am
by JCS
The original image in this thread appears to show a good example of the failure of the black seal between the glass bowl and the filter body. It looks like that seal has been seeping for some time.

I once renewed one of these in France on an XK140 /150 and I know from that experience that there are similar filters on various cars of very slightly different diameters.

In addition the actual filter body sealing area was very fine. Just be aware of having the correct seal on hand, the outer diameter of which must be a firm fit in the filter top. If that filter ring tends to drop down and out of the filter head the ring is too small.

Re: Petrol leak

Posted: Mon Aug 31, 2020 10:22 pm
by Glyn Ruck
Yes ~ that top seal looks shot & really gooey unless someone has put some sealant on it.