King Air Beech Brake Master Cylinder Upgrade/Repair Kit

Marsh Brothers’ Brake Master Cylinder upgrade & repair kit is a proactive solution that will eliminate the risk of failure due to leaks at the piston rod seal. By eliminating typical O-ring failure modes, this upgrade kit will increase mean time between unscheduled maintenance events keeping your aircraft in the air longer, while reducing maintenance costs associated with your brake master cylinder. Like all Marsh Brothers products, our glands and seals are developed to last for the long haul.

Installation of the Marsh Brothers brake master piston rod seal offers the opportunity to practice preventative maintenance, by eliminating the risks associated with the typical failure modes of traditional O-rings used in dynamic seal applications.

The Marsh Brothers Aviation King Air brake master cylinder upgrade kit contains all of the hardware to repair/upgrade your King Air brake master cylinder. Additionally, the kit also includes tooling to aid in the re-assembly. The piston rod seal (AeroLas™-Flex) provided is a Marsh Brothers Aviation proprietary lip seal design and is manufactured from a proprietary elastomeric polymer. The Marsh Brothers Aviation Thorseal® replaces both the OEM O-ring and rod wiper. The kit also includes installation instructions, instructions for continuing airworthiness and an authorized release certificate.

Note: The Piston is not included in this kit.

Caution: Thorseal® is made from Marsh Brothers proprietary material known as AeroLas™-Flex. AeroLas™-Flex is not compatible with phosphate ester hydraulic fluid, commercially known as Skydrol. Exposure to phosphate ester hydraulic fluid contamination will damage the seals.

• Applicable to OEM P/N 90-380001-23, 90-380001-29, 90-380001-33 series brake master cylinders.
• Piston Rod Lip Seal eliminates risk of typical failure modes associated with traditional O-rings used in dynamic applications.
• The proprietary elastomeric polymer offers improved lower pressure sealing performance and overall cold weather performance.
• Installation Tooling included - Seal compression ring, thread sleeve, and push tube.
• Delivery documentation includes copies of all STC certificates and a Transport Canada Form One (authorized release certificate) to keep your logbook up-to-date.

• Approved for installation in Canadian Registered aircraft by Transport Canada Supplemental Type Certificate No.  SA21-5 and US Registered aircraft by FAA Supplemental Type Certificate SAO4634NY, and Brazilian Registered aircraft by ANAC Supplemental Type Certificate 2024S08-04.
  
• TC Supplemental Type Certificate
  
• FAA Supplemental Type Certificate - Part 1
• FAA Approved Models List
• ANAC Supplemental Type Certificate 2024S08-04
• ANAC Approved Models List

Refer to ANAC Approved Models List

Brake Master Cylinder Kit Picture

Note 1: The Piston is not included in this kit.

Note 2: Kit Includes:
Installation Aids, Seal Compression Ring, Thread Sleeve, and Push Tube.

 Installation Instructions