Overview

Nobody pays much attention to the piston rod seal in their brake master cylinder until it starts leaking. Even when it does leak it won't cause much more than carpet damage, unless you ignore it. When your brake master cylinder requires repair due to leakage or you want to take a proactive approach, the Marsh Brothers’ Brake Master Cylinder upgrade/repair kit is the solution that will fix it once and for all. 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 the dynamic seal applications.

The Marsh Brothers Aviation Bonanza/Baron brake master cylinder upgrade kit contains all of the hardware to repair/upgrade your Bonanza/Baron brake master cylinder. Additionally, the kit also includes tooling to aid in the re-assembly. The piston rod seal 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 is not compatible with phosphate ester hydraulic fluid, commercially known as Skydrol. Exposure to phosphate ester hydraulic fluid contamination will damage the seals.

This kit does not fit brake master cylinders manufactured by Gerdes or Paramount.

 Features

• 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.

Resources

Specifications

• Applicable to OEM P/N 96-380034-25 & 96-380034-23 series brake master cylinders manufactured by Commercial Aircraft Corp.
• NOTE: This kit may fit other OEM brake master cylinder part numbers. Please contact customer service for further details.
• 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 (FAA), and Brazilian Registered aircraft by ANAC Supplemental Type Certificate 2024S08-04.

Approved Models

Refer to

Contents

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