Description
KN30400-G – RELAY/EMERGENCY VALVE
PART NUMBER(S):
Fleet Products: KN30400-G
OE: 106345, N4301CB, 2504433C91, KN30100, KN30200, KN30400, 065450, 065451
Automann: 170.KN30400
DESCRIPTION:
Model: RE-6 Relay Emergency Valve
Vehicles: Compatible with trailers, converter dollies, and exempt brake systems (pre-FMVSS 121)
• Valve Type: Dual-function relay and emergency valve
• Function: Controls trailer emergency and parking brakes, combining relay actuation with emergency shutoff
• Actuation Type: Pneumatic relay-operated
• Mounting Style: Nipple mount, 3/4"-14 NPT (pipe nipple)
• Material: Die-cast aluminum (corrosion-resistant)
• Weight: 3.7 lbs (1.68 kg)
• Dimensions: 159.3 mm (L) × 124 mm (W) × 113.8 mm (H)
• System Compliance: Not FMVSS 121 compliant (designed for exempt systems)
• Operating Temperature: -40°F to 200°F (-40°C to 93°C)
• Crack Pressure: 3.0–4.5 PSI
• Emergency Application: Initial 20–45 PSI
• Full Release Pressure: 65 PSI max
Port Configuration:
• Reservoir Port 1: 3/4"-14 NPT × 3/4"-14 NPT (pipe nipple)
• Reservoir Port 2: 3/8"-18 NPT (plugged)
• Emergency Supply Port: 1/4"-18 NPT
• Service Port: 1/4"-18 NPT
• Delivery Ports (x4): 3/8"-18 NPT
• Auxiliary Reservoir: Plugged
• Exhaust Port: Integrated dust shield
Applications:
Used on trailers, converter dollies, and non-compliant FMVSS 121 applications to manage emergency and parking brake control. Provides air delivery and isolation functions, enabling air brake application when the system reaches specified pressure and controlling emergency shut-off when disconnected or vented. Designed for legacy and exempt trailer systems requiring robust and field-serviceable relay/emergency valve performance.
CROSS-REFERENCE(S):
KN30400, KN30400N, KN30400X, RE-6, 106345, 034008, 34008, 281865RX, 170.KN30400, 170KN30400, EMK-34008, R955KN30400, EKN30400, VTC-77440, AVKN30400, 401287, TVKN30400, KN30400P, 745-KN30400, BWKN30400, 2504433C91, 3949405, KN30400PTP, RFKN30400, BENKN30400, BANKN30400, BXKN30400, WAKN30400, ZACKN30400, HKN30400X, MIDKN30400, TLAKN30400, KN30400BXW, R955KN30400N, TWDBENKN30400, S-17743, RE-6NC, N4301CB, 36-MB-KN30400, ZZKN30400, 745-KN30400X, WBW-KN30400X, VK1022W, 277186, 279291, 279549, 279657, 281711, 281865, 281869, 281870, 285553, 12350X, 110200N, 110200X, 12350N, A99036X, AF99036, N4301CA, N4301CC, N4301CD, PAN4301CB, EMDKN30400X, E-BN281865X, 110200, 110460, 110470, 110475, 418-1-150, A99036, EM-36100, EM-36140, LEV-3610, OTR281865, AV30400, S-9322, WAKN30400, KN30400P, AVKN30400, AV30400, 66507, 222053, 7J7235, 10607819, 2AT135, 4194297144, U55 KN30400, U55 KN30400X, 3-843-010004, 1777, 5053, 712000051, 72201-5002, SEA110205, 2000320005, F224701
A cross-reference listing means this part may be a compatible replacement for these part numbers based on OEM or distributor data.
IMPORTANT INSTALLATION NOTES:
✔ Mount using 3/4"-14 NPT nipple; ensure tight but non-over-torqued fit
✔ Plug auxiliary reservoir if not in use—only one active reservoir required
✔ Torque emergency piston cap nut to 200–250 in-lbs if servicing
✔ Cap screws to 100 in-lbs; exhaust screw 80–120 in-lbs if following RE-series guidelines
WHY CHOOSE FLEET PRODUCTS | KBR - HEAVY DUTY TRUCK & TRAILER PARTS?
• Canadian-owned since 1985
• Trusted by fleets, mechanics, and B2B partners across North America
• Fast, Reliable Shipping Across North America
• Competitive pricing with Core Return Refunds
• Price Match Guarantee | Find a better price? We'll beat the difference by 10%!
Warranty Information
