These master cylinders have been designed for a very long life and ensure very long trouble free service. We have tested them at 200,000 cycles with success (twice the life of the aircraft).
The piston is protected from dust by a lipseal.
Please note, Aircraft Spruce's personnel are not certified aircraft mechanics and can only provide general support and ideas, which should not be relied upon or implemented in lieu of consulting an A&P or other qualified technician. Aircraft Spruce assumes no responsibility or liability for any issue or problem which may arise from any repair, modification or other work done from this knowledge base. Any product eligibility information provided here is based on general application guides and we recommend always referring to your specific aircraft parts manual, the parts manufacturer or consulting with a qualified mechanic.
Yes, you would need an external reservoir for these master cylinders.