"Misting" shocks are often misdiagnosed asfailures. When a shock is subjected to rough roads, it's fluid can become extremely hot. Under these conditions, small amounts of this hot fluid evaporate off of the piston rod while it's under the dust cover. When the evaporated fluid reaches the cooler outside air, it condenses and forms a film or “mist”on the outside of the shock body. When mixed with road debris and dust, a large film of "hydraulic grime" will often form on the shock. This is a natural phenomenon caused by modern soft suspensions, and rough roads, and is not a failure.
A leaking shock is caused by a worn piston seal which allows fluid to escape from the top of the shock's body. The fluid is pushed out with each extension, causing almost all of the fluid to escape in a short period of time. At the time inspection, leakers have usually lost all oftheir dampening. Unlike misting shocks, which generally show larges patches of film, a leaker may show signs of fluid that flowed in streams down the shock’s body. Evidence of these streams can most easily be seen when the shock is fully extended.
When the road gets rough, that is when you need your shocks the most! That why truck OEMs and Fleets rely on Gabriel to design shocks to resist fade due to heat created in severe conditions. Unlike competitive shocks, Gabriel shocks with HT fluid are uniquely design to work at 50% higher operating range. Gabriel HT fluid with viscosity additives helps maintain performance and does not begin to break down until 320 degrees vs. 220 degrees for AW fluid. In addition, Gabriel Heavy Truck shocks use a self-compensating metal spring-loaded piston ring for constant performance vs. a nylon piston sleeve found in automotive shocks that do not expand with temperature, allowing excessive blow -by as the fluid thins with heat. So while other shocks become ineffective, Gabriel is still working strong at high operating temperature. It is at these temperatures the thin film of hot fluid on the piston rod can evaporate off. As a result, misting will occasionally occur . This is a good thing!