MacPherson-strut upper mountings have some features like bearings on rubber blocks. Check the fixing plate nuts for Firmness.
The front dampers may also be attached to their attaching positions at each end by a pivot bolt through a bushed setting or, each end may have a threaded pin going through the mounting bracket. Yet still, you may an eye and bolt at one end and a threaded pin at the other end.
The upper mounting in the case of a MacPherson strut is a bearing on a rubber-bonded block, set to a plate bolted to the structure. On the lower end is a ball swivel joint.
Normally, dampers are set inside the springs of a coil-spring suspensions mechanism.
With coil-spring parallel-wishbone front suspension, the damper is usually inside the coils spring.
The spring is set firmly in the lower wishbone, and links through the upper wishbone to a mounting on a chassis unit outrigger.
Checking for damper leaks
The dampers are saturated with a special oil which provides the needed damping effect. The piston and rod that moves up and down inside the strut pushes the oil through narrow passages, which reduces the oil transfer.
This action reduces the up-and-down movement of the car suspension.
The point of weaknes of the damper is the gland seal that is round the part of its body where the piston rod that moves up and down is. It is common for this gland to go bad and or fail, allowing the escape of oil.
This oil leaks make a dark stain in the road grime that builds up on the damper and on its mounting locations. So If there are any indications of a leak, dampers should be replaced
Always replace dampers in pairs to ensure a uniform suspension damping on the two sides of the car.
Inspecting for damage
Check each damper housing for signs of damage brought about by flying stones or deep rust. Minor dents may not be too serious, however deep dents should be investigations further, preferably by removing the unit from the car for close inspection.
Check the piston rod. It may be concealed by a rubber dust cover, which can be removed
Inspect the rod for signs of scoring or rust. And if there is signs of any, replacement of the unit is recommended, this prevents the damage of the piston oil seal.
Use a clean dry cloth to wipe the damper clean and check the rubber bushings at the base of the system. check for signs of damage, decaying, cracks or irregularities.
Make the lower body of the system firm and try moving it backward and forward .Twist it about its mounting bolt. If the rubber bushing is in good condition, there should be no movement what so ever.
Do same to the upper-mounting bushing and if the upper mounting is a pin,the condition of the rubber discs should be inspected.
Inspect any upper mounting on the inner front or rear wings. You may need a torch or inspection lamp to see this well.
Turret top weakness (point in where the damper is fitted) is common. Reinforcing plates can be welded to give firmness, but this is usually a job for a professional and if there is any worn or cracked rubbers, replacement should take place
SEE ALSO:HOW TO TIGHTEN BRAKE FITTINGS