BRAKES: If your master cylinder reservoir is constantly low on fluid, yet no leaks are evident outside the car, you may be seeping fluid out of the back of the master into the brake booster. To check this, simply remove the two bolts that attach the master cylinder to the booster (you do notneed to disconnect the brake lines from the master cylinder), pull the master forward and wipe your finger around the back. If it comes away wet, you have found the problem. NOTE: Overzealous bench bleeding can cause this. When bench bleeding the master cylinder, make sure that you actuate the piston only a short distance. If you attempt to bottom the piston within the master cylinder bore, you will dislodge the internal seal.
STEERING: You will find a rather unusual innovation on Lincolns built after 1963. In order to isolate the driver from road vibrations and noise, the factory incorporated three steering gearbox insulators between the box and the frame of the car. (They do for the gearbox what motor mounts do for the motor.) If you feel that your steering is loose, and you have checked all the usual suspects, give these a look-see. You can determine if they are bad simply by having someone turn the steering wheel as you peer into the engine room. If the box pulls away from the frame excessively, you have found your problem (remember that these are made of rubber so some movement is expected). NOTE: When the insulators become extremely loose, the steering shaft can rub against the shift tube, physically moving the shift lever as the wheel is turning. Don't allow yourself to get in this dangerous situation. Rebuilt steering box insulators are only $35 each exchange.
ENGINE: Lincolns are notorious for exhaust manifold leaks, especially passenger's side. Most often this will manifest itself as a slight ticking sound, especially when the engine is cold (don't confuse this with a simple loose spark plug). Look for telltale signs of soot or burning. If you have a small leak, do not ignore it for too long. A prudent repair will avoid the extra labor and expense of having to remove the head to resurface an area that is eroded by the leaking exhaust gas. We have new, replacement, passenger's side, made even stronger than factory, for only $345 each, including gasket.
CONVERTIBLE: 61-63 Lincolns use brake fluid in the convertible top hydraulic system. 64-67 systems use automatic transmission fluid. It is entirely legal and moral (not to mention less messy) to use transmission fluid in the 61-63. However, in order to do so you must completely clean and flush the old brake fuild from the system. You never want to mix the two fluids or you will have a thick, jelly-like, mess that the pump cannot handle. Also, don't even think of using silicone brake fluid or hydraulic oil. One more important item: always leave 1 to 1.5 inches of space between the fluid level and the filler opening to allow for fluid expansion.
WINDOW: I receive many requests for parts to cure windows that have become slow and unreliable. Before buying that new window motor that you think will fix the problem, put aside a day to "field strip" the complete assembly. Most slow windows are the result of original factory grease having become dried out and sticky. In effect, doing exactly the opposite of what grease is intended to do. While you are in the door, check that all of the rollers and pivots are cleaned and properly aligned. These steps usually return the speed you are looking for.
HEAT/AC: Starting in 1966 Lincoln experimented with a few variations of Automatic Temperature Control. The system allows the driver to choose a comfortable temperature and the car will do what is necessary to make this happen. To accomplish this, the engineers use a string of temperature sensitive resistors to feed information to the Master Control Unit (the brain). The 69-71 Mark III has one of these ambient air sensors mounted on the recirculating door in the lower right hand kickpanel. Because this door moves, the wires attached to the sensor are often flexing and can break. If your system suddenly stops responding and only puts heat on the floor, check here first.