03876X – Master Cylinder Fill Cap with O-Ring and Diaphragm

The 03876X Fill Cap Assembly is a replacement master cylinder cap that includes an integrated O-ring and diaphragm, designed to seal the reservoir and prevent fluid leakage or contamination. Commonly used in hydraulic brake systems on trailers, this cap maintains proper internal pressure and ensures brake fluid integrity.

Features:

• Complete replacement cap for master cylinder reservoirs
• Includes integrated O-ring and rubber diaphragm
• Prevents dirt, moisture, and air from contaminating brake fluid
• Helps maintain correct internal pressure in brake system
• Durable plastic and rubber components for long service life

Specifications:

• Part Number: 03876X
• Type: Master cylinder reservoir cap
• Includes: Cap, O-ring, internal diaphragm
• Material: High-strength plastic cap, rubber O-ring and diaphragm
• Application: Trailer hydraulic brake systems
• Fitment: Fits select master cylinders used on trailer surge brake actuators

Fitment:

• Compatible with many trailer surge brake actuators from major brands
• Typically used on hydraulic master cylinders for utility, boat, and cargo trailers
• Shown in diagram (17)