Expo/Expo LRV, Montero, Pickup & Ram-50

Before diagnosing Load-Sensing Proportioning Valve (LSPV), ensure all other brake components are operating properly. When all other brake system components are determined to be okay, ensure LSPV spring length is within specification. See Figure or Figure. Also refer to LOAD-SENSING PROPORTIONING VALVE (LSPV) under ADJUSTMENTS.
After spring length is determined to be within specification, connect pressure gauges to input and output ports of LSPV. See Fig 1 or Fig 2. Bleed the brake hydraulic system. Refer to BLEEDING BRAKE SYSTEM .

Fig 1: Connecting Pressure Gauges To LSPV (Expo/Expo LRV)
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Fig 2: Connecting Pressure Gauges To LSPV (Montero, Pickup & Ram-50)
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
On Expo/Expo LRV, loosen turnbuckle to relieve spring tension. See Figure. Slowly depress brake pedal and check readings on pressure gauges. See LSPV PRESSURE SPECIFICATIONS table. Tighten turnbuckle until spring length is 4.00" (101.6 mm). Slowly depress brake pedal and check readings on pressure gauges. If fluid pressure is not within specification, replace LSPV assembly.
On Montero, disconnect spring at support and pull spring and lever toward support until spring length is 8.9" (226 mm). See Figure. Without depressing brake pedal, check readings on pressure gauges. See LSPV PRESSURE SPECIFICATIONS table. Push lever away from support until spring length is 10.1" (257 mm). Without depressing brake pedal, check readings on pressure gauges. If fluid pressure is not within specification, replace LSPV assembly.
On Pickup and Ram-50, remove load-sensing spring. See Figure. Slowly depress brake pedal. Check readings on pressure gauges. See LSPV PRESSURE SPECIFICATIONS table. Install load-sensing spring. Load weight into rear of vehicle until measured spring length is 7.0" (178 mm) with lever pressed in slightly.
Slowly depress brake pedal. Check readings on pressure gauges. See LSPV PRESSURE SPECIFICATIONS table. If fluid pressure is not within specification, replace LSPV assembly.

LSPV PRESSURE SPECIFICATIONS

Application

Inlet Pressure psi (kg/cm² )

Outlet Pressure psi (kg/cm² )

Expo/Expo LRV

Turnbuckle Loosened

Test 1

1066 (75)

455-526 (32-3 37)

Test 2

1992 (140)

888-1002 (62-70)

Turnbuckle Tightened

1992 (140)

1571-1813 (110-127)

Montero

LSPV Spring Pulled

Test 1

1422 (100)

873-1002 (61-70)

Test 2

2560 (180)

1129-1314 (79-92)

LSPV Lever Pushed

2560 (180)

⁽¹⁾ 1863-2148 (131-151)

Pickup & Ram-50

LSPV Spring Removed

Test 1

853 (60)

242-327 (17-23)

Test 2

1992 (140)

370-540 (26-38)

LSPV Spring Installed

1992 (140)

⁽²⁾ 299-583 (21-41)

⁽¹⁾	Maximum side-to-side pressure differential is 57 psi (4 kg/cm² ).

⁽²⁾	On vehicles with both 2WD and heavy-duty suspension, outlet pressure is 526-697 psi (37-49 kg/cm² ).