Are proportioning valves repairable?
The proportioning valves are not repairable and should never be disassembled. They rarely fail, and all other causes of a brake problem should be thoroughly investigated before changing this valve. The valve is located either on the right fender apron or directly below the master cylinder.
How do you unlock a proportioning valve?
Place a flare nut wrench on the rear cap nut to the rear brake line. Instruct your assistant to hold the brake firmly, while you open the cap nut with the wrench. If the brake pedal does not move downward, have your assistant stomp on the brake pedal with medium to hard pressure, and hold it down firmly.
How to check the LSPV load sensing proportioning valve?
Install the LSPV gauge (SST) and bleed the air. 3. Raise the front brake pressure to 50 kg/ cm2 (711 psi) and check the rear brake pressure. 1. Brake pedal should not be depressed twice and/or returned while setting to the specified fluid pressure. 2.
How does the Toyota load sensing proportioning valve work?
Over time however, many people find that off road, the stock Toyota system doesn’t put enough pressure to the rear, and end up tying the end of the arm up under the bed to get maximum braking power to the rear. I ran my brakes this way for years on my 1990 Toy and was very happy with the added rear braking power.
What does the proportioning valve do on a car?
The brake proportioning valve is a metering device that equalizes the pressure between the front and rear brakes. The valve stops the flow, or pressure of brake fluid to the rear drum brakes during every heavy braking or emergency stops; otherwise, the rear brakes lock up and skid,…
What is the LSPV valve on a Toyota 4Runner?
Removal of the stock Toyota Brake LSPV (a.k.a. Proportioning Valve) In trying to work out the brakes on my 4Runner build-up, it came time to address the stock load sensing proportioning valve (LSPV).