brakes release at a maximum of 65 psi trailer supply (emergency) line pressure as the trailer air brake system is recharged to full operating pressure. 5. With tractor and trailer air brake systems fully charged, stop engine Reduce pressure by making a series of foot valve applications, and note that trailer brakes apply automatically at approximately 20 psi, tractor reservoir pressure or at the automatic emergency setting of the tractor protection equipment, if installed. If the valve does not function as described, or if leakage is excessive, it is recommended that it be replaced with a new or remanufactured unit or repaired with genuine Bendix parts available at Bendix HVSG outlets. REMOVING AND INSTALLING REMOVING 1. Block trailer wheels. 2. Drain trailer system air reservoirs. 3. Identify and disconnect air lines from valve. (Note: the emergency  piston  and  valve  assembly, generally referred to as the "insert" can be removed without line removal.  To remove the insert, remove the exhaust cover and pull insert out.) 4. Remove mounting bolts, or unscrew from pipe nipple mount INSTALLING If valve will be flange mounted directly to steel, it is - recommended that a flange gasket be utilized to prevent electrolytic action between the unlike metals.  If the valve is adapter or nipple mounted directly to a reservoir, it is recommended that "Never Seez" lubricant be applied to the threads before installation.  This will prevent galling of the threads and make removal easier. 1. Clean and inspect all connecting line and hoses for cracks, deterioration or damage.  Replace as necessary. 2. Mount valve securely 3. Connect all lines and hoses to valve DISASSEMBLY (Ref.  Figure 4) 1. Mark cover (1) and body (9) to assure proper positioning when assembling. 2. Remove cap screws (27), lockwashers (26) and exhaust cover (25). 3. Remove check valve (20) and check valve spring (21) and O-Rings (22 & 24).  Remove spring (23). 4. Remove exhaust diaphragm screw (30), diaphragm (28), and washer (29) from exhaust cover. 5. Remove cap screws and lockwashers from cover (1) 6. Remove cover (1), relay piston (3) and piston return spring (5) (if so equipped).  Remove piston O-Ring (2).  Remove O-Ring (8) from body bore. 7. Remove exhaust valve seat (4) from piston. 8. Remove sealing ring (6) from body 9. Remove filter assembly (7) from emergency (supply) port.  (Note: If new insert is to be installed, omit steps 10-1 5.) 10.  Apply downward  pressure on emergency piston (11) and remove emergency piston and inlet/exhaust valve assembly. 11.  With Tru-Arc pliers, remove large valve retainer (19) from bottom of emergency piston assembly. 12.  Push through small end of emergency piston (11) with finger and remove inlet/exhaust valve assembly 13.  Remove emergency piston O-Ring (10) and O-Ring (15) from inlet/exhaust valve assembly. 14.  Remove retaining ring (18) from  inlet/exhaust valve assembly. 15.  Remove valve guide (17), spring (14), retainer (13) and valve guide O-Ring (16). CLEANING AND INSPECTION OF PARTS Wash all metal parts in mineral spirits. Wipe rubber parts dry. Inspect all parts for wear, damage or deterioration. Clean or replace all filters. Replace all rubber parts and any other part not considered serviceable by these inspections. ASSEMBLY  (Ref.  Figure 4) Note All torque specified are assembly torque and can be expected to fall off after assembly.  Do not re-torque after initial assembly torque fall.  For assembly, hand wrenches are recommended. Prior to assembly, lubricate all O-Rings and mating surfaces with Dow-Corning 55-M pneumatic grease (Bendix Pc.  No. 291126).  (Note: If new insert is installed, omit steps 1-6.) 1. Install O-Ring (16) in valve guide (17) 2. Install valve retainer (13), spring (14) and valve guide (17) to inlet/exhaust valve. 3. Compress spring by holding valve guide and install retaining ring (19).  Make certain the ring is properly installed in groove. 4. Install O-Ring (15) on valve guide. 5. Install inlet/exhaust valve assembly into emergency piston.  With Tru-Arc pliers, install valve retainer (19) making certain it Is in groove. 8-7