1974 Jaguar XJ12

Thanks foxy, but I already have another product, hopefully it’s as good. I’ve used regular POR15 and like it.

When I went into the workshop this morning I found there was fuel in the spare tyre well and on the floor under it. Once I’d cleaned it up I put some more in the right hand tank to see where it was coming from.
It was leaking from the left hand pump, so I quickly drained the tank.
Pulled the pump out and immediately saw the problem.





That’s the gasket I’d made from a old inner tube. It appears it doesn’t like petrol. I’ve since bought some proper gasket material, so I made a fresh one.









Turns out the tank had a pinhole in it. It’s in an area right on the bottom, underneath the fuel
out/return unions and difficult to see from the sender unit hole.
So I cleaned off the paint and put some solder on it.
Then stood the tank up and put a couple of litres of Evaporust in. It can sit for a few days.
Once the rusty surface is clean, I’ll treat it with sealer.
The sealer I have is a KBS motorcycle kit. It has two prep products and the sealer itself. Anyone used it and had success with it?



Was sick of mechanical stuff so I spent a little time straightening the lower grille. Nice bit of stainless, just needed a little hammer and dolly work.
Before:









After:





By no means perfect, but a lot better than it was. It sits under the front bumper, so it’s fine.



Thanks.

Rear brake seals and pistons arrived, so got them rebuilt.
Pretty straightforward, cleaned up and reassembled.






And after another degrease and pressure wash, remounted the calipers and lock wired the mounting bolts.
Greased all the suspension and u joints after pressure washing, while access is reasonable.
Also dropped the diff oil, will refill before I reinstall the subframe.

During assembly, certainly easier than it would be with the subframe in the car.







Discovered that the brake hose between the body and the subframe is blocked, so that was probably the biggest reason for the brakes dragging.
First time I’ve experienced that. I had heard of it, but always thought it was highly unlikely.
I had opened the bleed screws and tried to tap the pads away from the discs. No fluid came out, so there was no movement. The pistons were rusty so even if they weren’t seized, that needed doing anyway.

Put the base plate back on, after a surprising amount of beating back into shape.








Returned to shape nicely though.


Thanks

The rear subframe is now back in the car.



I know that looks just like the removal photo, but believe me there is less 50 year old oil and grease on it!

It was a breeze really, remove and replace.
Actually the whole brake job was straightforward, access is not great, through the subframe, but reasonable. Handbrake also, Mark!
I definitely wouldn’t like to do it with the subframe in the car. But with it at waist height, in front of you, not bad at all.
I would really have loved to take the whole thing to bits and make it all like new, but that’s just not how this thing is going to be. It’ll be a car that looks (and is) good on top. And under the bonnet. I’ll probably be the only one who sees it’s underside, and I have too many projects already.


I decided to replace the front brake hoses. So I might as well see if it needs seals etc in the front calipers. So I removed the rhs caliper.
After doing so, I found a couple of shim washers on the floor. There are 3 in the stack leaning on that screwdriver.






Couldn’t really see where they came from. So I took the other side caliper off and it seems they fill the gap between the caliper and the steering arm.








Disc on the right, caliper carrier ( yellow line ), steering arm ( red line ).
I’m pretty sure the caliper goes against the carrier and the shim washers go between the caliper and the steering arm. If you know this is wrong, please let me know.

Pulled apart the driver’s side caliper. A bit of mucking about to get the pistons out. Used air pressure to push them out, but with 4 of them all connected it’s a bit complicated. If there was one supply pipe to each piston it would be easy…

Once they were out, they came up like new after a brief rub with 600 grit. One piston cleaned up, 3 to go.











Could probably just put them back together, but have new seals on the way.

Thanks

I think your assumption is wrong. Mine came off washers between caliper and the wheelholder.

Great read! I love these cars. Beautiful shape and such a nice drive.

I was just presuming you were in the UK and started spotting things.. lack of any real rust on a 50yo jag for starters. Then the kopacoat tin. Then the mention of kbs coatings (I use their rust seal on customers vehicles)

Finally - the gum trees near the shed in the first pic. Ah ha!

So since you're in this part of the world you'll know the obvious engine choice for your Jag if the engine is shagged - as seen here on a mates car I had in for some work...








He's very happy with his jags powerplant...

When I ordered the seal kit they said that the Jaguar kit didn’t have the seals to go between the two halves. That’s probably why the book says not to separate them.
The kit I have ordered apparently has them, so I can separate them, should I want. Not sure it’s needed though.

Cleaned up the rhs caliper.
Not sure what they are made of, they don’t seem to rust and they don’t seem to be plated, but they’re heavy. Like cast iron heavy.
Before.





And after.







I won’t pull the lhs one apart until I have the seals and this one reassembled.

I spent the rest of the day getting rid of some of the piping that clutters the top of the engine.
It’s all stuff that was connected to the air pump, that didn’t have a drive belt, so therefore wasn’t pumping air.
This made access to the top of the engine in general, and the sparkplugs in particular, much better. I should have done it earlier. No photos though, it could incriminate me.
Had to make some cap things to block off the holes this left in the intake manifold, but conveniently forgot to take photos…
Was almost thinking of trying to start the engine, but when I put some fuel in it and tried the pumps, the one that was leaking, that I thought I’d fixed, is still bloody leaking.
Hopefully I’ll get that sorted tomorrow and I might try and start it.

Thanks

Nice job buddy, pita bout the recuring fuel leak, but i doubt itl be long now before the big cat purs again.

That’s going to take a bit more work than mine.
The expansion tank had some sludge in it, but seems ok. I think it’s copper. Would that be right?