6
TESTING PRESSURE CAPS
A pressure pump and a cap adaptor are required to test the cooling system cap. This
kit does not include cap adaptors. Cap adaptors are available, contact you sales
representative or outlet.
1. Carefully remove pressure cap from the radiator when system is COOL.
2. Check cap and verify it is the correct pressure range for the system.
3. Make sure that all parts of the cap, tester head and adaptor are clean and free
from defects. So not attempt to readjust the components, replace defective parts
as necessary.
4. Apply water to rubber gasket of pressure cap and install on the radiator cap
adaptor. Apply water to the rubber gasket of pump and install on the other end
of the radiator cap adaptor.
Hold tester with radiator cap adaptor hanging down. (Some pressure caps have a
free of loose relief valve and will not seal unless testing in this inverted position).
5. Operate the pump, watching the pressure gauge. Check the pressure at which
the cap starts to relieve pressure. Compare with cap pressure rating. The cap
must hold pressure below its rating. It must relieve pressure above its rating.
A cap is satisfactory if it holds the proper test range for one minute or more.
If the gauge indicator hand falls quickly, replace the cap. Replace the cap if it
does not perform properly.
