EMPI Brass Brake Line Plugs, M10 x 1.0 Bubble Flare, Pair | VW Dune Buggy, Sand Rail & Master Cylinder (18-1103-0)

Seal off an unused brake port the right way. The EMPI Brake Line Plugs (part 18-1103-0) are solid brass, male-threaded M10 x 1.0 plugs with a bubble flare (ISO flare) seat. They thread into any unused M10 x 1.0 brake port and seal on the same seat a brake line would. The usual job is a spare port on the master cylinder of a dune buggy, sand rail or Baja Bug after the brake plumbing has been simplified. They also cap a spare outlet on a brake tee or junction block. Sold as a pair.

Vehicle Fitment

These plugs fit by thread and seat type, not by vehicle. They fit any port that takes an M10 x 1.0 bubble flare brake line, which is the standard thread on air-cooled VW brake systems.

• Dune buggies, sand rails and Baja Bugs built on VW running gear
• VW Beetle, Super Beetle, Karmann Ghia, Type 2 Bus, Type 3 and Thing master cylinders, brake tees and junction blocks with M10 x 1.0 ports
• Off-road and custom builds using an M10 x 1.0 master cylinder, such as the EMPI buggy master cylinders

Check before you order: this plug will not seal an SAE inverted-flare port (3/8"-24 or 7/16"-24 threads, used on many American master cylinders) or a larger M12 x 1.0 port. If you're not sure what your port is, send us a photo and we'll confirm it.

Key Features

• M10 x 1.0 male thread matches the standard air-cooled VW brake port
• Bubble flare seat seals metal to metal on the port's seat, just like a flared brake line fitting
• Brass construction won't rust and won't gall the port threads
• Sold as a pair, which covers both spare outlets on a typical buggy master cylinder
• Made by EMPI, the long-standing name in VW off-road and performance parts

What's Included

Two (2) M10 x 1.0 bubble flare brake line plugs. No other hardware is included or needed.

Installation Notes

• Clean the port's threads and seat before fitting. Grit on the seat is the most common cause of a weep.
• Thread the plug in by hand first to make sure it isn't cross-threaded, then snug it with a flare-nut (line) wrench. Don't over-tighten; brass is softer than steel.
• Don't use thread sealant or PTFE tape. The flare seat does the sealing, and tape can end up in the brake fluid.
• Bleed the brakes after any change to the hydraulic system, then pressure-test with a firm pedal and check the plug for leaks before driving.
• Plugging a port changes how your brake circuit works. Make sure the circuits that are left still brake the wheels you need them to.

Technical Specifications

Frequently Asked Questions

What are brake line plugs used for?

They seal a brake port you're no longer using. On a dune buggy or sand rail, that's usually a spare outlet on the master cylinder. They also cap an unused outlet on a brake tee or junction block.

What thread size are these plugs?

M10 x 1.0 metric, with a bubble flare seat. That's the standard brake port thread on air-cooled Volkswagens.

Will they fit an American master cylinder?

Only if its ports are M10 x 1.0 bubble flare. Most American master cylinders use SAE inverted-flare ports (3/8"-24 or 7/16"-24), and these plugs won't seal those.

Do I need thread tape or sealant?

No. The bubble flare seat makes a metal-to-metal seal. Tape or sealant can contaminate the brake fluid.

How many plugs come in the package?

Two. They're sold as a pair.

What are they made of?

Brass, which won't rust and is gentle on the port threads.

Do I need to bleed the brakes after installing them?

Yes. Bleed the system after any change to the brake plumbing, then check for leaks with a firm pedal before driving.

WARNING: This product can expose you to chemicals including lead, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.