After the recent purchase of our 1967 Jaguar Mark II, we are going through the car to get it roadworthy. The Jag hasn't been driven for several years, so tune-up, oil change, battery and brakes are on the list. Fortunately the paint (dark blue) and red leather interior are excellent. The only cosmetics will be some chrome work.
In last month's Driving Old Cars, we fixed the automatic choke for the twin SU carburetors. This month will feature changing the oil and beginning the brake system rebuild. Oil changes on old cars used to be easy. You went to the parts store, bought the oil and filter and changed the oil. Not any more. We have to consider non-detergent, detergent, straight weight, multi-viscosity and zinc content. I have always had to learn things the hard way, and here is what I've learned about oil and why.
I contacted Valvoline and found out the zinc had been reduced on most motor oils. Non-detergent zinc remained about the same. The zinc content in their 20W50 VR1 racing oil had not been reduced because, being racing oil, it is rated as off-road. I have always and still use 30-weight Valvoline non-detergent in my straight 8 cars (pre-1955) that have not been rebuilt with their blocks baked* and oil galleys cleaned. The one time I didn't follow this rule was on my 1946 Packard straight 8 (282 CID). We rebuilt the engine, cleaned out the oil galleys by pressure washing with mineral spirits, but didn't bake it. This time I used 30-weight detergent oil. After about 50 miles, the engine began to squeal, the oil pressure dropped and by the time I got it cut off, #5 rod bearing was toast! When we dropped the oil pan, there was a pile of sludge and the oil pump screen was clogged. It was the original engine, too! Never again! On my 1936 Packard straight 8 (320 CID), the engine was removed, baked and fitted with modern insert bearings. I switched to Valvoline 20W50 racing oil and have never had a problem. The VR1 is what I use in all of the 50's and up V-8's, foreign and domestic.
Oil filters are another concern. I have bought most every kind out there, and have cut them in two, concluding that the one the car was born with is the best: GM = AC-Delco, Jaguar = Jaguar, and when the manufacturer is no longer in business, like on the Packards, Napa makes (in my opinion) an excellent filter.
When I changed the oil on the Jag Mark II, I first read the factory manual. It was written in the 60's and suggested a Castrol 20W50 or straight 30-weight for higher mileage engines. Both were detergent oils and were made before zinc levels were lowered. I decided to use the Valvoline VR1 and to get a factory oil filter--the original Crossland #403 is hard to find, but I found and bought two of them on the Internet. After draining the oil, I carefully removed the oil filter. There is the usual bolt at the bottom of the canister, but there is a bolt in the housing that you dont want to touch. It is the pressure relief valve. Once the canister was removed, I laid the parts out and compared them with the manual illustration. I was missing a steel washer and fiber washer. After cleaning everything up and painting the canister the correct light green hammered paint (info from resto-guide) I assembled everything back to original. Inside the canister the spring goes on, then a flat washer, fiber washer and a metal plate that goes in dome-up (if this plate goes in upside down, it might affect oil pressure), then the filter. The top of the filter will sit just shy of the top of the canister. Now for the tricky part: The canister housing has a groove that the rubber O-ring goes into (similar to GM and other cars of this period). Using a lift is the only way I can see to get this done. The old O-ring has to come out, and to put the new one in can easily be done with a smear of grease; just enough to stick the O-ring in place. When the canister is installed, hold the canister so that it doesnt rotate as you tighten the bolt. Dont let the canister spin or it will cut the O-ring. Again, I have let the canister spin to tighten it down, started the car and the O-ring blew (fortunately in the shop) but I managed to shut off the engine before any damage was done.
BRAKES: The '67 Mark IIs had 4-wheel disk brakes and a brake servo for power assist. Getting the right brake fluid for British cars is imperative. These cars use a DOT 3, but it must be LMA(low moisture activity). If this is not used, other brake fluids will swell the rubber parts in the system. Castrol makes a GT-LMA and it is available on line. When we removed the wheels, we noticed that the front hubs had grease fittings on them for easy lubrication without removing the dust caps and bearings. Each caliper was photographed and removed. The rotors were rusty but not scored, so we cleaned them up using a die grinder with scotch brite pad. The caliperspistons were locked up and will have to be thoroughly cleaned and rebuilt. We bought new caliper and master cylinder kits, brake hoses and pads. In an upcoming issue we will rebuild all components and bleed the system. Brake servos can be rebuilt, but new ones are being made that are reported to work better--we'll let you know.
Spring is here. Time to get the cars out! See you at the shows, and keep 'em driving!