No retrofit I know of. VERY early ones had a check ball in line for the oil. The check ball seat wears out. This type would have an external oil tank. Other issues are bad spindles. If the spindle gets hot it will sweat the tool in over night and give you all sorts of headaches in the morning. Normal tool Knock out is .02-.04.
Newer type has a "Lucifer" valve on the front of the cylinder. Looks like ( and it is) a solenoid on the base of the unclamp cylinder. Those do go bad and leak. This will cause the unclamp pressure to drop, especially in manual tool unclamp. |