Hydraulic Jacks have become very popular in both construction sites and professional use, as well as for personal use. There are two different types of jacks, the bottle jack and the floor jack. They both work on the same system, it's just that unlike the bottle jack the floor jack is laid on its side and has different internal seals and check valves. All jacks work in 6 parts; the reservoir which holds fluid, the pump which moves the fluid, the valve ensuring flow into the main cylinder; at this point, the fluid raises a ram piston and then the release valve brings the fluid back to it's original place, the reservoir. The jacks are very sturdy and last, if you take proper care of them you can extend their life even longer. They are ideal for moving heavy equipment or construction materials as well as for personal use for changing tires of your vehicle.
Firstly you need to get acquainted with your jack. Make sure that when you use it that it's securely put on a hard and leveled surface. If the surface is soft the jack may actually sink under the weight, you also don't place it on an uneven surface as it may tip over while it is lifting the load. There are cases where the jack has literally been kicked out of it's position and the load was dropped, this is especially dangerous if you are changing a car tire. Also, remember that if you have a bottle jack make sure that it is never put on its side or with the ram upside-down as it may cause it to malfunction during us.
There are many different types of jack depending on the purpose and the weight loads you needs it for. Be sure to purchase the correct jack for the purpose as it is important that you don't overload it as it is going to make the internal seals break. If you worry that you may have overloaded your jack you can check by looking for leaking oil around the ram. This is a sure indication.
Though these are hydraulic jacks, it is not necessary to add any type of fluid or hydraulic oil to them during their lifetime and use. Only on certain occasions when you've found that there is a leak is it necessary to add any extra oil. Sometimes, in uncommon cases air is introduced and in this case in order to relieve lifting issues oil can be added. If you feel that there is a need to add oil you can do this by first finding the three screw heads. Two are for checking the valves, and the third is for adding fluid. Whatever you do do not open the valve screws. You can easily lose the small components. You can find the fluid fill screw on the cylinder body. You will find "oil" written on it. This is the only place you can add oil to, do not attempt to add oil anywhere else. When adding the oil make sure that the reservoir is full by waiting for the fluid to exit the hole. Also, it's important that the ram is in the lower position.
There are cases where there may have been air introduced into the main cylinder of the hydraulic jack. In order to fix this raise the ram all the way up and then using the release valve lower it. You will need to listen for a slight "psst" sound as the air escapes the main cylinder, you can do this by opening the fill oil screw slightly. All of the air may not escape on the first time, which may require you to repeat this a couple of times. Again, do not open the other two screws which are to check valves, if you do you will simply add more air to the cylinder.
Understanding Your Hydraulic Jack