Though the methods used to install cylinders in the suspension to support a hydraulics system will vary from vehicle to vehicle, there are half a dozen common suspension types that have standardized installation techniques. If you have a solid axle suspension, an A-arm, torsion bar, leaf spring, strut or chain bridge suspension, you'll find you can install cylinders by following a few relatively simple steps.
Mount cylinders atop the low-profile coil springs if you have a solid axle suspension. Attach a washer to the top of the sleeve of the cylinder so that the cylinder pushes up against the frame when it fills with oil. To facilitate the unimpeded passage of the cylinders, it will probably be necessary to cut away some of the sheet metal in your trunk.
Attach your cylinders to the coil springs of an A-arm (or I-beam) suspension by drilling 1.5-inch holes in the suspension donut at the point at which the cylinder intersects with the donut. The cylinders should be oriented at about a 15-degree angle, pointing upward and inward, and fastened into place with screws through the donut holes.
Expect that the piston rod for a torsion bar suspension cylinder mount will come pre-drilled. Simply orient the cylinder with its cap facing up, and attach it to the coil spring that juts up into the shock tower. Then, reinforce the shock mount bracket by welding a metal plate to it.
Use a frame mount and a leaf spring bracket to attach cylinders to a leaf spring suspension. The cylinder should run through the frame mount, with the cap's top edge touching the bottom side of the frame mount. The cylinder cap will also push against the coil spring, and you'll have to attach a leaf spring mount to the bottom of the coil spring to ensure the cylinder pushes against its piston properly.
Install hydraulics cylinders to a strut suspension by welding the original strut plate to the suspension spring. Let it cool, and then notch the strut housing about 2 inches so that the cylinder you install in the housing, which will rest straight, doesn't push beneath the bottom of the strut housing. Reinforce the cylinder, if necessary, and keep in mind that every car manufacturer's strut suspension is different, and you may need to use a different method--which a professional can teach you--depending on the make of your car.
Bolt the hydraulics cylinder shaft to your axle tubes if you have a coil-over suspension, and weld a cylinder to both side brackets of a chain bridge suspension. Chain bridge and coil-over suspensions are tricky to install cylinders on, but LayItLow.com offers a detailed explanation of the process, including diagrams (see Resources below).
