Today it is impossible to imagine loading and unloading, installation or repair work without the use of jacks - special mechanisms designed to lift heavy loads. The most effective hydraulic jacks are those in which the working force is created using a piston and hydraulic oil.
Instructions
Step 1
The undoubted advantages of hydraulic jacks are the rigidity of their structure, high carrying capacity, smooth running and, in general, high efficiency. However, like any other mechanism, the jack can fail for a variety of reasons. So, during long-term operation, air bubbles can accumulate in the working cavity of a hydraulic jack, which significantly reduces its efficiency.
Step 2
Typically, this can be caused by air trapped in the hydraulic system due to lack of oil. Here's how, for example, you can fix this malfunction on a rolling jack.
Step 3
First open the bypass valve and the oil tank plug, and then quickly, several times bleed the jack pump. Thus, air from the working cavity will be forced into the oil container. Then you can close the bypass valve and the oil tank opening. If everything was done correctly by you, then the air will be removed and the jack will work again in normal mode.
If the attempt was unsuccessful, all of the above steps should be repeated. However, this is not the only way to remove air from the working cavity.
Step 4
It is not difficult to determine the presence of air in the working cavity: the jack either does not work at all, or slowly lifts the load. First of all, unscrew the shut-off needle by one and a half to two turns, then by hand by the screw, lift the plunger to the extreme upper point and release it so that it is again in the lower position.
Step 5
Repeat this operation twice or thrice. In the future, so that such a problem does not arise, periodically check the oil level in the jack and, in case of a shortage, add it. Another reason for jack failure can be dirt trapped in the working cavity. To remove it from there, unscrew the head of the case, pour kerosene into its base and pump the jack with the unscrewed locking needle. At the end of the operation, the kerosene should be removed and clean oil should be poured into the working cavity.
