When the hydraulic pressure gauge on a piece of mechanical equipment begins to fail, you should replace it immediately. If the hydraulic pressure gauge is not working correctly, then the hydraulics could fail. The hydraulics can power brakes, a clutch, a loading bucket, or some other moving apparatus, so there could be serious injury waiting to happen if they fail. Replacing the hydraulic pressure gauge on the hydraulic system is not an overly difficult process. However, there are some steps you should take to do this successfully and without problems.
Step 1: Release Hydraulic Pressure
Before you can loosen up the hydraulic pressure gauge, you will need to release any of the pressure that is currently in the lines. This can be done with a pressure relief valve, or simply draining out the old hydraulic fluid. Place a bucket underneath the outflow valve and open it up to drain out the fluid.
Step 2: Remove Old Pressure Gauge
After all of the fluid has been removed from the system, you can then take off the hydraulic pressure gauge. You will find that there is a nut on the bottom of the gauge meter that you can use with an adjustable wrench. Set the wrench to the appropriate size of the nut. Place the wrench on the nut and make sure that the wrench is secure. Twist the gauge in a counter clockwise rotation to loosen the pressure gauge. Once the pressure gauge is loosened up enough, you can then remove it with your hand.
Step 3: Clean Threads
Take a look at the current condition of the threads in the stem where the pressure gauge was housed. You may need to use a tap and die in order to correct the threads if they have been crossed by the previous pressure gauge. If the threads look good then you can blow out any excess dirt or other debris with some compressed air. This can be from a can of air or with an air compressor.
Step 4: Put Tape on Threads
Before you can replace the old hydraulic pressure gauge with a new one, you will need to ensure that there are no leaks that can cause the gauge to give a false reading. The Teflon tape is a great way to do this, as it is easy to apply and seals up threads. Many plumbers use this type of tape to seal off water leaks. Start at the top of the threads and wind the tape around it until you reach the bottom. Make sure all of the threads are coated with the tape and that it is firmly pressed into the threads.
Step 5: Replace Hydraulic Pressure Gauge
Place the new gauge on the stem and begin to screw it into place. Be very careful not to cross thread the gauge as you attach it to the system. Keep it upright and screw it as much as you can with your hand. Once it becomes tight, you can use the adjustable wrench to snug it. Do not overtighten. Replace the hydraulic fluid, and the pressure gauge should begin reading correctly.