AUTOKAY Hammerhead 80T TrailMaster MID Brake Master Cylinder — Mid-Size Go-Kart Single-Port with Integrated Reservoir

AUTOKAY's Hammerhead 80T / TrailMaster MID master cylinder is a direct-replacement single-port hydraulic brake master cylinder with reservoir designed for mid-size go-karts that use a rear-only brake line.

This replacement master cylinder fits Hammerhead model 80T go-karts, TrailMaster Mid models, many mid-size American Sportworks kits, and various Chinese-brand mid-size carts. It replaces engines’ rear-brake hydraulic assemblies where a single outlet to the rear caliper is required and includes the reservoir integrated with the cylinder body for a compact, ready-to-install unit.

Will this master cylinder bolt into my Hammerhead 80T or TrailMaster MID?

Yes — the cylinder is built to match common mid-size go-kart mounting patterns. The overall base length and bolt spacing align with many OEM mid-frame brake mounts, making it suitable for direct replacement on the listed models without major bracket modification.

• Mounting bolt center-to-center: 1 3/4" for frame compatibility.
• Overall base length: 4 1/4" to match mid-size kart brake bosses.
• Designed for mid-size American Sportworks and similar Chinese-brand frames.

How does the master cylinder connect to the brake system and what type of brake does it serve?

This unit features a single hydraulic outlet intended to feed a rear brake caliper only, so it’s used in go-karts configured with one rear disc or drum caliper. The integrated reservoir keeps the system fed with fluid and simplifies plumbing compared with separate-reservoir systems.

• Single port output: connects directly to the rear brake caliper hose or hard line.
• Integrated reservoir assembly: reduces leak points and eases installation.
• Hydraulic design suitable for standard brake fluids (follow vehicle manual for fluid type).

What are the package contents and key physical specifications I should check before ordering?

The product arrives as one complete master cylinder with the reservoir already attached; no additional brake components or hoses are included. Confirm the physical dimensions and port orientation on your kart before installation to ensure proper fitment and lever alignment.

• Included: 1 x master cylinder with reservoir as pictured.
• Mounting bolt spacing: 1 3/4" (measure your mount to confirm).
• Overall base length: 4 1/4" — check clearance near frame and pedal box.

What should I know about installation and compatibility caveats?

Installation is straightforward for mechanically inclined owners: remove the old cylinder, mount the new unit using the matching bolt spacing, connect the brake hose to the single port, and bleed the system. Because this is an international-market component, some labels and instructions may differ; verify fluid type, hardware sizes, and hose thread compatibility before installation.

• Bleed brakes after installation to remove air and restore firm pedal feel.
• Check thread size and adapter needs for your existing brake hose/banjo fitting.
• International product notes: packaging or instructions may vary from local OEM parts.

Who is this for: This AUTOKAY master cylinder is aimed at owners and mechanics of mid-size recreational go-karts — specifically Hammerhead 80T and TrailMaster MID models — who need a direct, cost-efficient replacement single-port hydraulic master cylinder with reservoir. It's ideal for riders who maintain or restore mid-size American Sportworks and comparable Chinese-brand karts and want a compact, ready-to-install hydraulic brake assembly that matches common mid-frame mounting and rear-only brake layouts.