Coil Spring Booster Installation

by Don Bowman

Coil spring boosters are generally used to compensate for weak or collapsed springs. There are several types on the market. One style is a screw in. This is a large twisted piece of metal that has a ½-inch square head. The other type is a spreader, which works well. The spreader type is a set of square plates with depressions for the springs. They are expanded with the use of long bolts and nuts. There is a round rubber insert the size of the spring but it is less effective; it helps to make the spring stiffer but does little to restore the height. The next one is an air bag that is inserted inside the spring and works like an air shock. The more air pressure, the higher and stiffer it gets. This is for the rear only. The last is a rubber spreader that is about 3 inches long, rectangular and has curved ends used to snap into the coils of the spring. They work for the most part, although keeping them in is sometimes a problem.

Raise and support the vehicle on jack stands. If you are installing the screw type, they must be 180 degrees or opposite of each other or the spring will warp. They are inserted using a ½-inch socket and ratchet. Start the spacer in by hand just enough to hold its position. Insert the socket on the head and push and twist at the same time. Do not try to screw it in any further once it stops. It will pop out with force if screwed in to far. Place one on the opposite side of the spring.

Install the spreader type on opposite sides of the spring. Loosen the nuts on the studs to allow the spreader plates to collapse to get them in between the spring coils. Insert the spreader to the point that the coil spring is seated into the spreader saddle. Turn the head of the bolt on the bottom until the spring is spread as much as desired and then tighten the plate nuts up so that they stay in place.

Install the snap on rubber type with a pry bar or hammer. Hold them in place and use the pry bar in between the springs to pry and snap the ends onto the coils. If that does not work, use a big hammer.

Install the air bags with a floor jack. Place the floor jack under the rear axle on the side that is to be done first. Raise the axle just a little bit to unload the shocks. Remove the bottom nut on the shock and pull the shock bottom loose. Lower the jack. Pull down on the axle and simultaneously pull the spring out of its perch. Insert the air bag into the spring and attach one end of the hose to the air bag.

Make sure that the air line is free from pinching or crinkling, and while pulling down on the spring insert the coil spring. Face it properly in its saddle where the depression is for the end of the spring. Make sure that the air line is free and facing the rear. Raise the axle with the jack until the shock can be pushed onto the mount and install the nut. Lower the axle and do the other side the same way. Locate a place for the air valve to go and drill a hole if necessary and insert the valve into the hole. Tighten up the nuts to hold it in place. The most popular spots for the valve are either in the rear of the trunk where it is easy to get to, or on the bottom of the bumper facing down. Attach the ends of the airlines to the valve and fill with air until the level of the vehicle is achieved.

Items you will need

About the Author

Don Bowman has been writing for various websites and several online magazines since 2008. He has owned an auto service facility since 1982 and has over 45 years of technical experience as a master ASE tech. Bowman has a business degree from Pennsylvania State University and was an officer in the U.S. Army (aircraft maintenance officer, pilot, six Air Medal awards, two tours Vietnam).