Brake Valve Linkage with Fitting Position Front Axle, Rear Axle

Correct the relationship between suspension height and rear brake proportioning after lifting your 4WD with Whiteline brake valve linkage components. These application-specific extension kits alter the linkage or mounting arrangement for the factory height sensing brake valve, allowing rear brake bias to be adjusted appropriately for the lifted suspension setup.

Also commonly referred to as a load sensing proportioning valve or LSPV, this type of system uses suspension height and load as inputs to rear brake proportioning. Changing vehicle ride height can therefore change the relationship between the suspension and the factory valve linkage.

What Does a Load Sensing Proportioning Valve Do?

A load sensing proportioning valve, commonly abbreviated to LSPV, helps control rear brake pressure according to the vehicle's suspension height and load.

Whiteline describes the factory system as a height sensing brake valve. A mechanical linkage connects the valve to the relevant suspension or axle arrangement, allowing its position to change as vehicle height and load change.

This helps the braking system vary rear brake proportioning according to the conditions the original system was designed around.

The LSPV shouldn't be confused with an aftermarket adjustable brake bias controller. Whiteline's components work with the compatible factory height sensing brake proportioning system rather than replacing it with a motorsport-style manually adjustable proportioning valve.

Why Does Lifting a 4WD Affect Brake Proportioning?

A suspension lift changes the vehicle's static ride height and therefore can change the relationship between the suspension and a mechanically operated height sensing brake valve.

If the factory linkage remains in its original configuration after ride height changes, the valve may no longer operate from the position intended for the new suspension setup. That can affect the rear brake proportioning commanded by the system.

Whiteline's brake proportioning valve extension components allow the rear brake bias of a lifted vehicle to be adjusted back to the correct vehicle braking bias.

It is safer to describe the issue this way than to assume every lifted vehicle will simply be interpreted by its valve as being lightly loaded. The exact operation depends on the original linkage, valve design and suspension arrangement.

What Does an LSPV Extension Kit Do?

An LSPV extension kit, or brake proportioning valve extension, changes the mechanical relationship between the factory valve linkage and the lifted suspension arrangement.

Whiteline uses two different configurations depending on the application.

Brake Proportioning Valve Extension Link Rod

One configuration uses an extension link rod with two nuts. The link rod changes the mechanical connection used by the height sensing brake valve so that the system can be adjusted for the altered ride height.

Whiteline's product information states that this arrangement allows rear brake bias on the lifted vehicle to be adjusted back to the correct braking bias.

Brake Proportioning Valve Extension Bolt

Another configuration uses an extension bolt and nut. Although the hardware differs from the link-rod design, its purpose is also to provide the adjustment required for the compatible factory rear brake proportioning system after lifting.

These components aren't universal adjustable proportioning valves. They are application-specific hardware designed to work with the existing height sensing brake valve and linkage.

Does the LSPV Need Adjusting After Fitting?

A brake proportioning valve extension shouldn't simply be installed and assumed to have produced the correct rear brake bias.

The purpose of the extension hardware is to allow the factory system to be adjusted back to the appropriate braking bias after the vehicle has been lifted. Correct setup is therefore an important part of installation.

Because the component affects brake proportioning, installation and adjustment should be performed or checked by a qualified technician familiar with the applicable braking system.

Requirements for modified vehicles can also vary according to jurisdiction and the extent of the suspension modification. Check the applicable requirements before modifying the brake proportioning linkage or other safety-critical braking components.

Do not remove, bypass or disable the factory load sensing valve as an alternative to correcting its linkage. The extension component is intended to retain the factory system while accounting for the changed suspension height.

Signs of Incorrect Brake Bias After a 4WD Lift

Changes in braking behaviour after a suspension lift can indicate that the complete braking and suspension setup needs inspection, but symptoms alone cannot diagnose an incorrectly adjusted brake proportioning valve.

A vehicle may feel unusually front-biased under braking, or braking behaviour may appear to change more than expected as load changes. However, these observations can have many other causes, including tyres, brake condition, brake adjustment, hydraulic faults and other suspension or braking components.

Don't attempt to diagnose rear brake proportioning purely from pedal feel or vehicle behaviour.

If braking characteristics change after lifting the vehicle, have the system inspected by a qualified technician. The condition and adjustment of the height sensing valve and linkage can then be checked alongside the rest of the braking system.

Brake and Suspension Checks After a 4WD Lift

A height sensing brake valve is only one system that may be affected when suspension height and travel change. A complete lift installation should consider the surrounding brake lines, cables, ABS wiring and suspension components rather than treating each accessory in isolation.

Brake Line Kits can provide additional movement around factory rear brake hose mounting arrangements on compatible lifted applications. ABS Components can reposition or extend ABS wire mounting where the original lead routing becomes too restricted after lifting.

Handbrake Parts may also be required where the parking-brake cable arrangement needs additional movement or repositioning.

These components solve different problems. An ABS wire extension doesn't correct brake proportioning, and an LSPV extension doesn't provide additional brake hose length. Each should only be fitted where required for the particular vehicle and suspension setup.

Shop Brake Valve Linkage with Whiteline

Use Whiteline's vehicle search to confirm the appropriate extension link or bolt configuration before ordering. Because these components affect brake proportioning, have installation and final adjustment completed or checked by a qualified technician.

Whiteline brake valve linkage components are covered by the applicable Whiteline product warranty, with Fitment Guarantee and 60 Day Returns providing additional confidence when selecting compatible parts.

Brake valve linkage is part of our brake parts range. Ride height changes affect more than the valve, so see our brake line kits as well.

If you're unsure whether your lifted suspension setup requires a brake proportioning valve extension, contact the Whiteline team for fitment and technical assistance.