I'm trying to remove the RH fuel tank on my '73 XJ12, but I can't seem to figure out how to remove the filler cap. I've searched through this branch of the forum, but can't find any mention of issues with the cap. Am I skipping a step not mentioned? Is there a trap door with a release? I cant find it. Maybe mine is just stuck. Please help

Thanks,
Patrick

 

When you open the cap to reveal the casting the cap is fixed to, you'll see four screws locating the assembly, (I think it's four, but it's a long time since I had these tanks out, it might be three). Anyways, the front ones are a PIA because the screwdriver wont go on straight 'coz the filler cap gets in the way ! So somehow you remove these screws, then try to lift the filler cap assembly off the petrol tank that lies below. This can be really difficult, believe me, as there is an 'O' ring to seal it, and the filler casting is Mazak that corrodes over the years and almost welds the filler assembly to the tank.

What you find, like I did, is that as it is all recessed, any attempt to use jemmy bars, and force etc, risks damaging your lovely paintwork !. I squirted a load of penetrating oil around the gasket, then tried rotating the assembly, again, very difficult. If you can make up some little wooden fulcrums you should be able to jemmy up at each end and break the corrosion seal. Do be careful, as this is not a quick and easy job.

Also, make sure you don't lose the end of the little rubber breather pipe down it's hole as it is a PITA to get it back out !!

 

I did remove the four screws. I also slightly damage my paint trying to pry it loose. That's when I stopped to post this. I will try some WD-40 and be more diligent/obsessed.

 

Hang on in there, and it will , (eventually) come out, but it IS difficult, no two ways about it.

I don't know if Doug Dwyer has anything to add............

 

Is there an incantation, or maybe some black magic pentagram bull$hit I can add to the mix?

 

I always tap out the roll pin for the lid with a pin punch before touching anything. From there you have easy access to all of the screws. Liberal use of a penetrating oil (PB or Liquid Wrench) will work far better than WD-40. Spray it all around the recess and lightly tap with a wrench or small hammer. From there try twisting the body rather than prying. A twisting motion should break it free upon which more penetrating oil is a good idea. If you need to pry (prise for you Brits), throw a bunch of rags in front and behind the filler and use two pry bars VERY gently to get it to rock. Getting it to the "twisting stage" makes this step far easier. Don't forget to make everything nice and clean before reinstalling!

 

Sorry for basically a double post of info.

Another idea I've played around with is using a slide hammer with 2 or 3 jaw puller in the filler hole. I haven't found one that was so corroded that I would have to use such heavy weaponry like that yet. Also, the bodies (and caps) did change through the years. This method would work best on a S1 filler as the S3s were more restricted.

If you're having trouble twisting the body there is another theoretical method I, again, haven't needed to use. Since you have an S1 your filler body is more or less open, use a tailpipe expander to grasp inside the hole. As it tightens, expansion will stop and start transferring force to twist the body. Twist until you've broken the seal.

 

Thanks to both of you. I got it to break loose today. Sunday morning it was around 70 degrees. Today at 93 degrees, the cap was so warm that it was almost uncomfortable. I guess the warmth helped make the seal easier to move. A couple of firm twists and it came off. Its pretty nasty. I hung it from a tree with some bungy chords, put some chain pieces and gas in it and shook it like an ugly baby. No good. Still junky. I think I will find someone around here to steam the tank.

 

I've gone through the XJ6 tank saga enough. I had one that was fairly decent treated by a radiator shop and I ended up with pinholes shortly after. Do some searching here and you'll find the multitude of complaints about the stock tanks. I have an aluminum fuel cell that I will be installing later this week. It will never rust and was cheaper than buying a new aftermarket tank.

 

If you cannot find ones from a running car - used all the time...do not even
bother.

Having them cleaned and coated is 2/3 the price of new and not near as
good...get new fuel sender gasket and O-ring at the top.

Be sure the top vent hose is in good shape...

Then when done, keep them full if the car is not used as a daily driver...
fill both of them....

 

Brand spanking-new tanks are now available here in the UK from David Manners Group. £178.80 (=$273). They ship worldwide.

Jaguar Parts detail from David Manners Ltd Partno-C40191*-PETROL TANK LH XJ S1/2

SNG Barrett have them for the Series 3, but I think you have to modify them a bit, like blocking off the fuel return pipe as a Series 3 car doesn't have one.

 

They sell through lots of outlets, made in Canada.

SIII tanks will fit all model, just block off the return line if not needed.
If a Series 1, you will need SIII fuel sender as it goes in from the rear and you
will have to lengthen the wires to the fuel sender.

 

I just got her running and took her around the 'hood. I used the apple cider vinegar method. I looked in the tank with a flashlight and it looked like new sheet metal. Now I need to pull the radiator and get it cored.

 

Glad to see you are sorting things out. What is this "cider vinegar" trick ?

 

Basically, you just fill it with acv and let ot sit. I left it for about a day and a half and just rinsed ot out. Clean as a whistle.

 

Slick!! Vinegar is a mild acid. Oughta do wonders for rust!!


Gotta remember that!

Although rust isn't a major issue around here.

Pin holes. Oh yeah!

A couple of decades ago, I was building a 32 Ford flat head 4. The oil sump had over an inch of dirt in it. not sludge, dirt!! I dug it out and got the thing really clean. Too clean, myriad pin holes and cracks!!! I made a mistake and decided to braze them closed. I ended up with a sump bottom entirely coated on brass!! Tinnned and soldered might have been a better course. but, it worked, No leaks and not rust prone there. I painted it in Gytal anyway along with the inside of the block.

Many decades ago, I got the fuel tank in my 27 T clean with gravel and tacks.

Carl

 

I tried sections of chain and a little bit of gas, but that just wasnt doing the trick. Today I back-flushed the block and radiator. Did some good. Now my power brake booster seems to have put itself on the list. Test drive yielded cooler running temp, but no power braking.