Subaru Forester AWD For Sale From UK At Reasonable Price
Do You Know About Double Tube Telescopic, When You Buy Subaru Forester Awd For Sale
A used buyer of Subaru forester AWD for sale should know that the shock absorbers of many modern cars are double tube telescopic type. In addition to the usual tube within the piston flows, they are also equipped with an annular gap around the inner tube (also known as the reserve or compensation chamber) where the oil moved by the stem is compressed. This step is managed by special control valves located on the bottom of the shock absorber.
Risk in Cylinder
Obviously, the piston also has the normal valves for regulating the hydraulic brake in compression and extension. This solution, compared to a classic single-pipe shock absorber, allows, first of all, to have a higher quantity of oil, to the advantage of greater thermal stability of the fluid. Furthermore, the compression chamber (the one where the piston slides) will be filled only with oil since the air only occupies the upper part of the annular compensation chamber. This will avoid, to some extent, the risk of air-oil emulsion in the pump cylinder. Sometimes a slight over-pressure is used, obtained with nitrogen placed inside the cavity, free or in sealed containers. In the first case, there will be some mixing of oil and gas during operation. The limits of the double tube are mainly two; the maximum inclination of mounting allowed a certain percent, otherwise the piston, during extension, would suck air from the high area of the air gap that would remain oil-free with a serious loss of efficiency.
The Piston Size
Smaller dimensions of the piston (to compensate for the presence of the annular chamber) and consequent lower movement of oil for the same external diameter. A used car buyer should try to reduce this limit by increasing the diameter of the stem, in order to move more oil. However, this leads to unwanted weight gain. Used car buyer who pays the Subaru forester awd price, should know that gases, unlike liquids, are compressible, so the chamber containing the gas, equipped with a diaphragm separating the inner tube, will decrease in volume in compression and increase in extension; This behavior will make a gas shock absorber easily recognizable once it has been removed from the vehicle.
The Solution
If you subject the piston to compression, the same, as soon as it is released with a stroke slowed by the hydraulic brake, it will return spontaneously to the position of maximum extension (pneumatic spring effect). Vice versa, in a conventional hydraulic-only shock absorber, if you move the piston by hand, it will remain stationary in the chosen position. Therefore, the gas also acts as a second elastic element, in addition to the main function performed by the spring. The gas chamber can be housed in the upper or lower end of the shock body; however, the first solution is preferable to avoid that, over time, there are possible gas leaks in the hydraulic body with consequent damaging gas-oil emulsion which would alter the correct operation of the shock absorber.
