Description

Overview

Sealco LOV-4 service relay valve provides fast, low opening control of service brakes on heavy trailer tandem axles. This piston style relay valve mounts on a nipple and responds to control port pressure to deliver reservoir air to four brake chambers. Additionally, it suits non ABS air brake systems where you want consistent application and release across both axles. As a result, it helps reduce brake lag and supports stable, predictable stopping performance.

Features

• Low opening 1.5psi crack pressure for smooth brake response on lightly loaded trailers
• Four 3/8″ NPT delivery ports to feed up to four service brake chambers on a tandem axle
• 3/4″ NPT reservoir port and 3/8″ NPT control port to suit common trailer air systems
• Suitable for non ABS applications using piston style four port trailer relay valves

Specifications and Materials

The Sealco LOV-4 service relay valve uses a 3/8″ NPT control port, a 3/4″ NPT reservoir port and four 3/8″ NPT delivery ports, so it integrates cleanly into standard heavy trailer brake layouts. Crack pressure is set at approx. 1.5psi, which allows the brakes to respond early without sudden grab while still maintaining control authority at higher line pressures. In practice, this configuration helps installers match replacement performance to existing tandem axle air systems on many road-going trailers.
Part number: AB8364.
For more technical information on four port service relay valves, see the manufacturer technical guide for reference

Compatibility and Fitment

This cross-reference listing means this valve is a suitable replacement for the part numbers and applications shown. Some changes in air line plumbing may be required. 110380, 110360, 110365, RV015, ESL110380, A103600, 55110380, 401131, 51442, 39540343, LOV4.

Compliance and Safety

Sealco engineers this LOV-4 service relay valve to meet heavy vehicle air brake performance expectations commonly applied to non ABS relay valves in on-road service. Consequently, it suits use in compliant trailer brake systems when you match the control, reservoir and delivery port sizes to the original design. Always mount the valve in the recommended orientation, tighten threaded joints to appropriate torque, and then leak test all air connections after installation. In addition, you should follow the trailer manufacturer’s inspection schedule and replace any valve that shows air leakage, sticking or visible damage.

Trailer Applications

You typically use this LOV-4 service relay valve on tandem axle semi trailers, dog trailers and other heavy equipment trailers that run four service brake chambers on the axle group. When you position the Sealco LOV-4 service relay valve close to the axle group, it shortens air line runs from the reservoir to each chamber, which improves timing and balance between axles. Additionally, it works well with common 3/8″ nylon air lines and suits maintenance replacements where an existing low opening four port relay valve has reached the end of its service life.

Cross-reference and Suitability

This part cross-references to or suits the following equivalent part numbers and compatible alternatives:

Use these references as a guide only and always confirm port sizes, crack pressure and layout against the original valve before substitution.

Why Choose ICS Trailers

Firstly, ICS Trailers specialises in heavy vehicle trailer parts, so our team understands how a service relay valve affects brake balance and response. Secondly, we keep key air brake components in stock, which helps workshops and fleets finish repairs quickly and minimise downtime. Furthermore, our staff can assist you to confirm compatibility with your axle group and air schematic before you commit to a replacement. Finally, we back every purchase with straightforward support, so you can rely on consistent supply for your trailer brake maintenance programme.
Browse Air Brake Parts at ICS Trailers in our online store