We are going through our 1967 Jaguar Mark II 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.  

        This article 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.

         The Jaguar Mark II brakes were completely locked up from years of sitting.  The Jag's brake system was pretty advanced for the time period including 4-wheel disk brakes with a vacuum power booster.

        The  system consists of one two-piston caliper on each wheel that straddles the disk and houses a pair of friction pad assemblies, each comprised of a pad and securing "keeper" plate.  The friction pads have a metal plate riveted to the back side of them, with a slot in the plate to guide and lock the pads to the pistons.  A "keeper plate" on the caliper fits over the pads to hold them in, and is attached to the caliper by one bolt/nut.  The caliper has two cylinder blocks, one on each side, holding the piston assemblies.  These operate the friction pads.  The pistons have two grooves to accommodate the rubber seals.  The innera pressure seal, and outera dust seal.  (Front calipers have a larger bore.)  There is a refractor pin in the center of the caliper bore and the pistons have a corresponding hole in them.  When the pistons are pushed into the caliper bores, the pin aligns them.  The pins are also designed to push the pads toward the rotors as the pads wear down.

        CALIPER REBUILD:  Before the calipers were rebuilt, we shot some detailed pictures, made notes and bagged and tagged all of the bolts.  We also referred to our shop manuals for rebuild instructions and parts book to see if we had any missing parts.  Before disassembly, the calipers were cleaned using brake cleaner and a wire wheel, then using air, the grit was blown away from all crevices.  The emergency brake assembly is attached to the rear calipers.  It is mechanical, not hydraulic, and has two pads that move via a hand brake.  Our mechanism worked and the pads were good, so we just cleaned it up and removed it from the caliper.

        PAD REMOVAL:  To remove our caliper pads, we removed the keeper plate.  The pads have a hole at the top of the metal backing plate and by inserting a wire through the hole it is easy to pull the pads out.

        INSTALLING FRICTION PADS:  Insert the new pads into the caliper so that the slot in the metal plate attached to each pad engages the stud button in the center of each piston (pad end).  With the pads in, put the keeper plate over the top of the pads and bolt to the caliper.

        PISTON REMOVAL:  To remove the pistons, we removed the four bolts from the cylinder blocks, the rubber dust seal from the groove around the cylinder block face and removed the cylinder blocks.  This left the piston exposed.  Ours were frozen, so it took time soaking them with brake cleaner before they could be pulled.  Now with the calipers disassembled, we could clean everything and lay the parts out on clean white rags.  Our cylinders were not scored and did not have to be re-sleeved.

        TO ASSEMBLE PISTON SEALS we used Jaguar-recommended Castrol GT-LMA (low moisture activity) brake fluid.  Using grease to assemble can swell the rubber seals, a common problem in vintage British cars using British rubber.

                                                With the seals lubricated, we put them on the pistons, pressure seal inner and dust seal outer.  Then we pushed each piston into its cylinder, aligning it with its refractor pin.  Care must be used not to twist the seals.  With the pistons in, we pulled the outer rim of the rubber dust seal into the groove around the cylinder block face of each piston, then reassembled the cylinder blocks to the calipers.  We reattached the emergency brake assembly on the rear calipers.  To finish, we masked off the pads and rubber seals then sprayed on a couple of coats of hi-temp cast.  The calipers are ready to put back on and in an upcoming issue we will complete the brake overhaul.


        Get the cars out, and keep 'em driving!