Tech Tip: Rear Axle Load Valve Causes Low Pedal

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Tech Tip: Rear Axle Load Valve Causes Low Pedal

The mechanical linkage and the valve cause problems on some trucks by leaking and increasing braking distances. The main culprits are rust and corrosion.

Brake and Front End Staff
By Brake and Front End Staff
Published:

Models: 1995-2004 Tacoma

One problem area is the load-compensating valve that attaches to the rear axle. The mechanical linkage and the valve cause problems on some trucks by leaking and increasing braking distances. The main culprits are rust and corrosion. The valve is designed to change brake hydraulic pressure in the rear brakes as the load changes the relationship between the body and the axle. Some techs have reported the spare tire can come in contact with the linkage if the carrier mounting points fail due to corrosion.

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When replacing the unit, it’s critical to adjust the linkage. On 2WD trucks, make sure there is 78 mm of distance between the center of the bolt on the axle shackle, and the center of the bolt on the arm that connects the linkage to the valve. On 4WD trucks, that distance should increase to 120 mm.

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Chassis

Buick Encore Alignment Service

Alignments are key to the health of the tires and some of the advanced safety systems like automatic emergency braking and lane keeping.

Andrew Markel
By Andrew Markel
Andrew Markel is the director of content for Brake & Front End magazine. He has been with Babcox Media for 20 years. He is a technician and former service writer and holds several automotive certifications from ASE and ­aftermarket manufacturers. He can be reached at [email protected].
Published:

The 2012-2022 Buick Encore is based on the Gamma II platform that is shared with the Chevy Trax. This has been the best-selling Buick for several years. Like a lot of modern vehicles, the alignment specs are tight with almost no adjustments built in except for toe. However, alignments are key to the health of the tires and some of the advanced safety systems like automatic emergency braking and lane keeping.
Front Suspension
The front suspension on the Encore has a single lower control arm and MacPherson struts. Some models have a suspension dampener on the front bolt of the lower control arm. The part helps to control vibration that could be transmitted to the subframe. If the caster is out of specification, look at the bushings on the lower control arm for damage. Camber can be adjusted by installing cam bolts in the lower hole of the strut mount. This should give ±1.75 degrees of adjustability. Inspection of the lower control arm is a critical part of aligning the Encore. The arm can be bent due to curb strikes and the bushings can quickly deteriorate. Also, inspect the sway bar links for any signs the ends have play.
Rear Suspension
The Encore comes in front-wheel-drive and all-wheel-drive versions. Both versions use a trailing arm beam axle. The camber and toe for the front-wheel-drive version can be adjusted with shims. Unfortunately, there are no adjustments for the all-wheel-drive version. If camber or toe are out of specification in the rear, look for a damaged wheel. If the thrust angle is out of specifications, inspect the trailing arm bushings.

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