I have a bostitch cap60p-of that will keep building pressure after 135 psi and wont shut off.
I have to manually shut it off. What part do I need to order for it.
The pressure switch is the device that turns the air compressor on at the cut in pressure level and is supposed to shut your air compressor off at the cut out pressure level.
If the air compressor tank pressure exceeds the normal cut out setting of that pressure switch, then that suggests strongly that your pressure switch has failed and you need a new switch right away.
If, however, the air pressure in the tank never gets to the normal cut out pressure setting of your pressure switch, that’s another issue.
Rather than retype all the info here, please see the troubleshooting page and the links to the page about why air compressors run on but do not build air pressure.
If you still require help, please add a comment here.