The pressure plate is one of three main friction components of your clutch system. It is a cast iron plate that provides a pivot fulcrum for the diaphragm spring, a friction surface for the disc and a mounting surface for the drive straps.
In much simpler terms, the Mercedes Benz pressure plate's main function is to apply pressure to the clutch disc for the transfer of torque to the transmission. This is a very important function since the pressure plate, when coupled with clutch disc and flywheel, makes and breaks the flow of power from the engine to the transmission.
To add further description, the Mercedes Benz pressure plate is like a spring-loaded clamp that is bolted to the flywheel. It consists of a sheet metal cover, heavy release springs, a metal pressure ring that provides a friction surface for the clutch disc, a thrust of ring fingers for the release bearing and release levers. The release levers lighten the holding force of the springs when the clutch is disengaged. Some high-performance pressure plates are "semi-centrifugal," meaning they use small weights on the tips of the diaphragm springs to increase the clamping force as engine revolutions increase.
There are three types of pressure plates that are used today. These are the long style, the Borg & Beck, and the diaphragm. The diaphragm is said to be the best plate for street use but then again, each of these three has specific advantages.
The long pressure plate is easily identified by the three thin fingers that engage the release bearing are used to identify the long pressure plate. Under the pressure plate cover is a series of nine coil springs. This style is mainly used for drag race applications where the static load can be adjusted separately from centrifugal load.
The second style which is the Borg & Beck style is somehow similar to the Long style. In fact, it is even considered as the street version of the Long style pressure plate. It can be identified by the somewhat wider three fingers that release plate pressure by compressing the coil springs found under the pressure plate "hat."
The diaphragm pressure plate, on the other hand, uses a single, large Bellville-style spring to load the pressure plate. This style of spring poses some advantages. First, it loads the pressure plate evenly since the pressure is equally applied to the entire plate assembly. Second, and more importantly, as the Bellville spring is compressed, it reaches a point where the pedal effort decreases when the spring over-centers therefore makes holding the clutch pedal in at a stoplight much easier than a coil spring type pressure plate.
A defective Mercedes Benz pressure plate may cause different problems. One is clutch clutter which may be attributed to damaged pressure plate release levers. Another problem is clutch slippage which can be caused by a damaged pressure plate and a dragging clutch which can be caused by damaged pressure plate-clutch drag.
Nowadays, pressure plates have constantly improved their main and primary responsibility, which is to obtain increased holding power.
It's therefore necessary to regularly check your to avoid problems and to replace it immediately when the need arises.
