For this installment of Elise Tech Tips I would like to cover a couple of technical issues that are fairly easy to address, yet dramatically increase the pleasure of ownership of the Elise. I also want to bring to light a relatively new failure that is being reported in an increasing number of Elises at this time.
The first item I would like to address only affects the ’05 model year Elise and it involves the adjustment of the brake pedal push rod to reduce the mushy brake pedal feel and pedal pad height problems with these cars as they were delivered from the factory. The ’06 and newer Elises have completely different pedals so this does not apply to the newer cars. The brake pedal pad height in the ’05 Elise as set by Lotus leaves a lot to be desired. The pedal stroke is very long which results in a low pedal pad height when the pedal is pressed to activate the brakes and this low height makes it very difficult to carry out proper heel/toe pedal actuation. The pedal also has a mushy feel at this height which, even though the brakes still work well, does not instill confidence in the braking system. A simple adjustment of the length of the brake master cylinder push rod will easily address both of these problems.
The most difficult part of this procedure is gaining access to the jamb nut on the master cylinder push rod where it screws into the brake pedal clevis in order to make the adjustment. This task involves assuming what I like to call the ‘Lotus Position’ which is you in the passenger seat on your back with your head under the dash board and your feet dangling out of the open top over the roll hoop cover. This position is not easy for a large or tall person to assume, and it can be very hard to extract yourself from the car once you have gotten yourself into this position. I suggest having an assistant available during this procedure to hand you tools and to help you get in and out of the car without damaging anything. To start, remove the footrest from the passenger foot well and cover the roll hoop cover with a beach towel or fender cover so you will not scratch it with your shoes. Sit on the passenger side frame rail cover and ease your head under the dash while you slide your posterior onto the seat bottom. Now raise your legs straight up and allow your heels to rest on the towel covered roll hoop. Now that you are uncomfortably upside down in the passenger seat with your head pressed against the firewall and you are looking up at the aluminum under tray of the dashboard, you have officially assumed the ‘Lotus Position’! Looking toward the driver’s side of the car you can see the brake pedal with the push rod attached via a clevis and the rod threaded into the clevis secured in place by a jamb nut. In the photo below, taken looking up from under the clutch pedal, the clevis, push rod and jamb nut are visible just above and to the left of the universal joint for the steering shaft. When looking at the push rod from the passenger side of the car, it will be directly above the steering shaft and to the clutch pedal side of the brake pedal.
Push the brake pedal down with your hand and you will see how the push rod system works. Note the brake pedal pad height at full pedal stroke and compare it to the throttle pedal height at rest. If it is lower than the throttle pedal an adjustment is needed to bring it to the same height. Have your assistant hand you an open end wrench and use it to loosen the jamb nut on the push rod. Lotus applied liquid thread lock to this nut and sometimes it is very hard to loosen. If the nut does not loosen with a reason-able amount of force, try tightening it first to break loose the thread locking compound and then try to loosen it. You only need to loosen it enough that the threaded push rod can be rotated easily at the pedal clevis. Now rotate the push rod using your hand or a small wrench on the flats on the rod to raise the pedal height. Only rotate the rod enough to raise the depressed brake pedal to the same height as the free height of the throttle pedal and remember that a small amount of rotation results in a large difference in pedal pad height. Having your assistant sitting in the driver’s seat pressing on the brake pedal with their foot while you check the pedal pad height can help with this process. Once you are satisfied with this adjustment, snug up the jamb nut and check the push rod for end play where it contacts the master cylinder plunger. The master cylinder plunger must not be preloaded by the push rod or your brakes will be activated slightly at all times causing the brakes to drag. By lifting the brake pedal with your hand and letting it drop, you can feel and listen for the necessary end play.
It is now necessary to adjust the brake light switch at the pedal. Many times these switches were poorly adjusted by the factory so the brake lights would not illuminate until you had fully pressed down the brake pedal. This is a potentially dangerous situation and with your new pedal height adjustment, the brake lights may not illuminate at all if this switch is not properly adjusted. Have your assistant watch the brake lights and tell you when they illuminate as you press the brake pedal by hand. You want them to illuminate almost immediately upon pressing the pedal. To obtain the proper adjustment the switch body can be rotated ¼ turn, the switch pulled out of its bracket and the actuating plunger pulled out of or pushed into the switch with a clicking action as necessary to achieve the correct length. It takes a considerable amount of force to ‘click’ the plunger in or out of the switch body so if it does not move easily, just pull or push harder on the plunger. When the plunger is the correct length, insert the switch back into its bracket and rotate it ¼ turn to lock it back in place. Once you have the switch adjusted, have your assistant help extract you from the car and you are set to take your first drive with a nice firm brake pedal, brake lights that come on immediately, and the ability to heel/toe shift the car with ease.
