Better Beaters - Building Cars and Daily Drivers

Things to do to get that old thing running. Part One.

Open wide and say... AHHH!

Now that I'm going to have space available in my garage, I need to have all my cars in running condition. The Mark VII is the only one that isn't currently running.

A while back I checked to see if the motor would turn freely. Luckily, I still have the replacement battery that I removed from the XJS, which still holds a good charge. I pulled the sparkplugs and squirted some Marvel Mystery Oil into the cylinders. I let that sit overnight then turned the key. The motor spun easily.

The carb linkage was stuck solid. I pulled the carburetors off and found that the butterfly shaft of the front carb was stuck in the carb body.  It was gummed up with what looks like shellac. There was also a broken bushing in the carb body for which I sourced a new replacement.

I changed the old oil and refilled it with Castrol 20-50w. These motors hold a lot of oil! When I replaced the oil filter cartridge I found that the supplied oil filter cartridge ring gasket didn't seal very well. It's very thin and wouldn't stay in position. My plan is to cut a wider gasket out of a sheet of gasket paper.

I traced the outline of the housing on a sheet of gasket paper.

I cut the center hole out with a very sharp utility knife.
I cut the outer circle with a steady hand and a pair of scissors.

I reassembled the filter assembly and the homemade gasket seemed to stay in the proper position.



What about the points, and vacuum advance? The vacuum advance canister arm is seized. Usually this will seize up when the engine has been sitting for a long time, so that it will remain in the retarded, at rest, position. This is a common problem with the XJS V12 and it can lead to overheating when being driven. I don't think that this will be an issue if I only run the motor for a short time.

There's no coolant in the radiator. I sure hope that the motor doesn't have a blown head gasket. This was a common problem for these motors, back in the day. I'll put that off for another day.

The fuel system will have to be addressed. I'm not going to mess with the tanks and pumps, yet. Usually I would just run a fuel line from the mechanical pump into a small gas can. The mechanical fuel pumps on older American cars work by creating a suction in one chamber of the pump, then forcing the fuel through a one way valve into the fuel line, creating pressure. Similar to the workings of the human heart.

An electric pump has to be located below the level of the fuel tank. Gravity causes the fuel to flow into the pump which pushes it down the line. My plan is to set up a small container above the level of the carbs and let gravity do the work.  Sort of like the system on a Model A Ford. The Model A stored the fuel in the cowl ahead of the windshield, not a comforting thought!

Maybe all they need is a good bath.

I'm going to dive in and disassemble, clean, and lube these carbs. I'd already freed the stuck throttle shaft. Hopefully they will be in good enough adjustment to get the motor running.

Since I had it apart, it was good time to clean this area up a bit.
I cleaned and chased those threads.

I made up some new manifold gaskets from a sheet of gasket material.
A hole punch was used to make the bolt holes, I cut the center hole with a utility knife.

I have to free up and adjust the hand brake system. That might be effective enough to use once I get the car running and moving, at least in and out of the driveway.

I've already removed the rt.front wheel brake cylinders. In an earlier post I showed how I used a grease gun to force the cylinder pistons out. Still have the left fronts to do.

Even that cheap little trolley jack will work using the jack points.
It doesn't inspire a lot of confidence. Be careful.

I jacked up the rear wheels to see how freely they turn. The good news was that they turned quite freely. The bad news was that the handbrake was engaged! Well, at least the handle was pulled up. I'm not going to be stopping the car with these any time soon.

This is a simpler system than up front. Just one wheel cylinder.

That little mechanism bolted to the cylinder activates the rear hand brake. It's and unusual
sliding cam design. Of course it was gummed up solid.

I thought that I should take a look inside the brake assembly and removed the rt. rear drum. (I found that the left had been previously removed!) Compared to the front brake, it is much simpler design. Just one wheel cylinder. It appears that the mechanical brake cable acts upon the wheel cylinder to engage the brake. On my old American cars, the cable works on a separate lever that engages the shoes without any help from the wheel cylinder. Not on this car. The entire cable lever and cylinder are seized up solid, there's no way that the handbrake will work without freeing up the works. That means disassembling the wheel cylinders. It looks like I should just dedicate an entire day to the task. At least the brake lining and drum look to be in pretty good shape.

There's not going to be an easy work around for the brakes.

The car also has a hydraulic clutch mechanism. I suppose that this was used to lighten the pedal pressure but it just adds some more complexity. There was also a vacuum booster for the brakes which had been removed by the original owner. His Son had told me that his Dad drove this car until he got too tired from dealing with the manual transmission and now unassisted brakes. The Jag was parked and the Bentley was pressed into daily service. (What a choice!) I wonder how much pressure the brake pedal requires?

No way getting around refurbishing all the hydraulics. Still, I could still try to get the motor to fire first, that would provide a lot of motivation to finish off the hydraulics. And, I could just do the rear brake cylinders first so I could use the handbrake system. Maybe.

Besides the hydraulic clutch, and vacuum brake servo there really isn't much complexity in the car.  If this was common car with easy availability of new cheap reproduction brake components I wouldn't be bothering to rebuild the system. I would just throw the old junk away. But I don't have that luxury in this case.  The parts are uncommon and expensive. I could have guessed.

I wanted a simple old car that didn't have any more equipment than what it takes to run the car. I didn't want to be saddled with getting an old automatic transmission to work. In many ways the Mark is similar to my old F250. It had power brakes and an automatic transmission but that was all. Hand cranked windows and a very simple heater and vent system.

There's still quite a bit of work to do and plenty of subject matter for the next installment.


I'll give this process a couple of weeks. If I'm not successful then it will go in the sideyard for another Winter!