for 13 15 18 Eaton Fuller Transmissions Air Line Kit - Faster Shifts

In this review the focus is on a simple replacement kit designed to restore proper transmission air pressure on Eaton Fuller style gearboxes. The kit is aimed at owners and technicians who need a straightforward fix for slow or clumsy air shifting: it replaces old fittings and installs four new 12in 5/32 air lines with modern push-in fittings and color coding so the valve receives more air volume. The single biggest reason to consider this kit is that it targets the common cause of slow shifts and synchronizer wear by increasing airflow and removing deteriorated or over-tightened fittings.

Key Features

• Updated air volume: Replacing the original line with a high-capacity 4-color air line improves air delivery to the transmission shift valve, which can produce faster, more positive shifts.
• Push-in fittings: New push-in fittings let the hose be inserted without risk of over-tightening and collapsing the line, preserving unrestricted airflow.
• Four 12in lines included: The kit supplies four ready-length 12in 5/32 air lines so installers do not need to measure and cut multiple runs for the shift knob to valve connection.
• Durable material: Made of flexible, repeat-bend resistant material that resists creasing and aims to reduce failures from worn or brittle tubing.
• Simple replacement: The kit replaces all fittings and lines between the shift knob and transmission valve, making the update straightforward for a technician or competent owner.
• Protects transmission: By addressing low transmission air pressure, the kit helps reduce synchronizer wear and the risk of costly transmission damage over time.

Who It's For

This kit is best for truck owners and fleet technicians who operate Eaton Fuller 13, 15 or 18 speed transmissions and are experiencing slow or harsh shifts, noise in gears, or suspect low air pressure to the shift valve. It is also useful for anyone doing routine maintenance who prefers to replace aged soft lines and outdated fittings before problems develop.

It is less suitable for owners who need a full custom air system with different lengths or nonstandard fittings; those customers should source custom hoses or consult a transmission specialist. Also, if the transmission problem is mechanical rather than air supply related, this kit will not address internal gearbox faults.

Pros & Cons

Pros

• Clear improvement in shift speed and responsiveness when low air volume was the issue.
• Push-in fittings reduce the risk of line collapse from over-tightening compared with old-style fittings.
• Four color-coded lines simplify routing and reduce installation time.
• Flexible, durable material stands up to repeated bending without creasing.

Cons

• Some customers reported mixed quality, so fit or finish may vary and inspectors should confirm parts on receipt.
• The kit replaces lines and fittings only and will not fix internal transmission issues unrelated to air supply.

Specifications

Compatible transmissions	13, 15, 18 Eaton Fuller style
Included air lines	4 x 12in 5/32 lines
Fittings	New push-in style air fittings
Material	Flexible, repeated-bend resistant tubing
Colors	4-color air line set for easy routing
Primary benefit	Increases air volume to transmission shift valve

Our Verdict

The kit is a practical, cost-effective way to restore proper air delivery for Eaton Fuller 13/15/18 speed transmissions and is good value for anyone facing slow or noisy shifts caused by low air pressure. It is quick to install, reduces the risk of line collapse with push-in fittings, and can prevent further synchronizer wear when the root cause is degraded lines or fittings.

Frequently Asked Questions

Will this kit fix any shifting problem?
It will help where shifting issues are caused by low air volume or collapsed/old fittings; it will not repair internal mechanical transmission failures.

Are the fittings reusable?
The kit includes new push-in fittings designed for single reliable installation; reuse of old collapsed fittings is not recommended.

Is this compatible with other 5/32 systems?
Yes, it is intended for Eaton Fuller style systems using 5/32 tubing and should work where that size and connector type are used.