An outlet valve installed in the expansion tank plug maintains the pressure within the specified limits and prevents damage to the system components. A cap with a defective valve must be replaced. But how do you check the expansion tank cap itself?
Instructions
Step 1
First of all, check the expansion tank cap for mechanical damage, scratches, cracks, wear and rust;
Step 2
Since any cover has three parts: a rubber mount, a snap ring, and a metal cap, the spring must be checked. To do this, it must be compressed. If you managed to do this easily, then it is time to change it, since the spring takes on pressure, and it can simply be torn off elementary if it passes this pressure;
Step 3
Pull on the vacuum valve, open it and check that it closes completely when released;
Step 4
Check the expansion tank cap vacuum valve seat for dirt. Make sure that there is no deviation from the standard when closing and opening the vacuum valve;
Step 5
Check the relief pressure on the expansion tank cap. To do this, connect a special device to it and screw the pump onto the cover, observing the instructions, and operate it until the valve opens. Remember to increase the pressure until the needle stops moving. Remember that the opening pressure of the outlet valve is (90-120) kPa and the closing pressure of the outlet valve is about 83.4 kPa. If the pressure does not correspond to the required value and is below 80 kPa, then replace the cap of the expansion tank;
Step 6
The same device can also check the cooling system itself for leaks by installing it on the neck of the expansion tank. Pressurize to 0, 12 MPa and check that the pressure gauge shows this value for 10 seconds. Otherwise, there are leaks in the cooling system that can be easily detected by the leakage of coolant;
Step 7
Be very careful when buying a new cover, as not all of them may fit. Be guided by the marking of the old cover.
