null

Safety-Air-Electrical

Shop semi truck gladhands, air tanks, semi-trailer cords, 7-way receptacles and more. We stock premium aftermarket replacement air system and electrical components to maintain your truck’s critical air line connections.
  • Product
  • Qty in Cart
  • Quantity
  • Price
  • Subtotal
  • FREE SHIPPING OVER $249
    R12V Type Relay Valve W/ 4 PSI Crack Pressure & Mounting Brackets Replaces 170.065303

    R12V Type Relay Valve W/ 4 PSI Crack Pressure & Mounting Brackets Replaces 170.065303

    AFTERMARKET

    $54.99
    R12V Type Relay Valve 2.61 X 1 Inch C To C Bolt Holes W/ Service, Supply & Delivery Ports* High Quality Relay Valve* R12V Type Relay Valve* 4 PSI Crack Pressure* Mounting Bracket Included* Ports:  -...
    09-05170496
    SKU:
    09-05170496
    Product Type:
    Air, Electrical, & Safety
    Make:
    Universal Items
    $54.99
    Qty in Cart: 0
    Price:
    $54.99
    Subtotal:
  • FREE SHIPPING OVER $249
    R12V Type Relay Valve W/ 4 PSI Crack Pressure & Mounting Bracket Replaces 170.065104

    R12V Type Relay Valve W/ 4 PSI Crack Pressure & Mounting Bracket Replaces 170.065104

    AFTERMARKET

    $52.99
    R12V Type Relay Valve 2.61 Inch C To C Bolt Hole Width W/ Service, Supply & Delivery Ports* High Quality Relay Valve* R12V Type Relay Valve* 4 PSI Crack Pressure* Mounting Bracket Included* Ports:  -...
    09-05170497
    SKU:
    09-05170497
    Product Type:
    Air, Electrical, & Safety
    Make:
    Universal Items
    $52.99
    Qty in Cart: 0
    Price:
    $52.99
    Subtotal:
  • FREE SHIPPING OVER $249
    SR7 Spring Brake Valve W/ 2 - 1.38 Inch M1 Mounting Studs Replaces 170.K021560, K021560

    SR7 Spring Brake Valve W/ 2 - 1.38 Inch M1 Mounting Studs Replaces 170.K021560, K021560

    AFTERMARKET

    $172.99
    SR7 Spring Brake Valve W/ 3/8 PLC Control & Balance Port, 1/2 NPT Supply Port* High Quality Spring Brake Valve* SR7 Type Spring Brake Modulating Valve* Includes:  - 3/8 Inch PLC Control Port  - 3/8...
    09-05170507
    SKU:
    09-05170507
    Product Type:
    Air, Electrical, & Safety
    Make:
    Universal Items
    $172.99
    Qty in Cart: 0
    Price:
    $172.99
    Subtotal:
  • FREE SHIPPING OVER $249
    Haldex Type Air Regulator Valve 3.5 Inch Height Replaces 170.KN31070

    Haldex Type Air Regulator Valve 3.5 Inch Height Replaces 170.KN31070

    AFTERMARKET

    $80.99
    Haldex Type Air Regulator Valve W/ 3/8 NPT Inlet & Outlet Port, 3/8 Inch 24 Threaded Post* High Quality Air Regulator Valve* Haldex Type* Adjustable From 10 PSI To 125 PSI* Includes:  - (1) 3/8 Inch...
    09-05170498
    SKU:
    09-05170498
    Product Type:
    Air, Electrical, & Safety
    Make:
    Universal Items
    $80.99
    Qty in Cart: 0
    Price:
    $80.99
    Subtotal:
  • FREE SHIPPING OVER $249
    E3 Type Single Circuit Foot Valve W/ 4 - 1/2 Inch NPT Delivery Ports

    E3 Type Single Circuit Foot Valve W/ 4 - 1/2 Inch NPT Delivery Ports

    AFTERMARKET

    $56.99
    E3 Type Single Circuit Foot Valve W/ 1/2 Inch NPT Supply Port & 1/4 Inch NPT Auxiliary Supply Port* High Quality Foot Valve* E3 Type Single Circuit Foot Valve* Ports:  - (4) 1/2 Inch NPT Delivery...
    09-05170503
    SKU:
    09-05170503
    Product Type:
    Air, Electrical, & Safety
    Make:
    Universal Items
    $56.99
    Qty in Cart: 0
    Price:
    $56.99
    Subtotal:
  • FREE SHIPPING OVER $249
    RT4 Type Multifunction Relay Valve W/ 4 PSI Crack Pressure Replaces 170.KN26000

    RT4 Type Multifunction Relay Valve W/ 4 PSI Crack Pressure Replaces 170.KN26000

    AFTERMARKET

    $76.99
    RT4 Type Multifunction Relay Valve W/ Service Tank, Control, Supply, Reservoir & Deliver Ports* High Quality Relay Valve* RT4 Type Multifunction Valve* 55 PSI PPV Closing Pressure* 4 PSI Crack...
    09-05170492
    SKU:
    09-05170492
    Product Type:
    Air, Electrical, & Safety
    Make:
    Universal Items
    $76.99
    Qty in Cart: 0
    Price:
    $76.99
    Subtotal:
  • FREE SHIPPING OVER $249
    MV3 Type Dash Valve Control Module W/ Integral Push-Lock-Connect Fittings Replaces 170.800840WF, 2506-188-C

    MV3 Type Dash Valve Control Module W/ Integral Push-Lock-Connect Fittings Replaces 170.800840WF, 2506-188-C

    AFTERMARKET

    $190.99
    MV3 Type Dash Valve 4.225 X 3 Inch C To C W/ 4 M6 X 1 - 6H Mounting Holes* High Quality Dash Valve* MV3 Type Dash Control Module With Integral Push-Lock-Connect Fittings* Operating Temp From -40 To...
    09-05170493
    SKU:
    09-05170493
    Product Type:
    Air, Electrical, & Safety
    Make:
    Universal Items
    $190.99
    Qty in Cart: 0
    Price:
    $190.99
    Subtotal:
  • FREE SHIPPING OVER $249
    MV3 Type Dash Valve Control Module W/ Knobs, 2 Spool Manifold & 6 - 1/4 Inch NPT Ports Replaces 101890, 14539

    MV3 Type Dash Valve Control Module W/ Knobs, 2 Spool Manifold & 6 - 1/4 Inch NPT Ports Replaces 101890, 14539

    AFTERMARKET

    $125.99
    MV3 Type Dash Valve 4.187 X 3.031 Inch C To C W/ 4 - 1/4 Inch 20 Threaded Mounting Holes* High Quality Dash Valve* MV3 Type Dash Control Module With Knobs* Manifold 2 Spool* (6) 1/4 Inch NPT Ports*...
    09-05170494
    SKU:
    09-05170494
    Product Type:
    Air, Electrical, & Safety
    Make:
    Universal Items
    $125.99
    Qty in Cart: 0
    Price:
    $125.99
    Subtotal:
  • FREE SHIPPING OVER $249
    QR1C Type Quick Release Valve W/ 5-8 PSI Crack Pressure Replaces 170800348, 800348

    QR1C Type Quick Release Valve W/ 5-8 PSI Crack Pressure Replaces 170800348, 800348

    AFTERMARKET

    $17.99
    QR1C Type Quick Release Valve W/ NPT Supply, Delivery & Balance Ports* High Quality Quick Release Valve* QR1C Type Quick Release Valve* Integral Double Check Valve* 5 - 8 PSI Crack Pressure* Ports: ...
    09-05170488
    SKU:
    09-05170488
    Product Type:
    Air, Electrical, & Safety
    Make:
    Universal Items
    $17.99
    Qty in Cart: 0
    Price:
    $17.99
    Subtotal:
  • FREE SHIPPING OVER $249
    PPDC Type Dash Valve W/ Integral Push-Lock-Connect Fittings Replaces 065661, 065661BXW

    PPDC Type Dash Valve W/ Integral Push-Lock-Connect Fittings Replaces 065661, 065661BXW

    AFTERMARKET

    $132.99
    PPDC Type Dash Valve 3 -1/4 Inch 20 Threaded Mounting Holes, 3 X 2.54 Inch C To C* High Quality Dash Valve* PPDC Type Dash Valve With Integral Push-Lock-Connect Fittings* Ports:  - (2) 3/8 Inch PLC...
    09-05170489
    SKU:
    09-05170489
    Product Type:
    Air, Electrical, & Safety
    Make:
    Universal Items
    $132.99
    Qty in Cart: 0
    Price:
    $132.99
    Subtotal:
  • FREE SHIPPING OVER $249
    SR7 Type Spring Brake Valve Replaces 170.K021557

    SR7 Type Spring Brake Valve Replaces 170.K021557

    AFTERMARKET

    $155.99
    SR7 Type Spring Brake Valve W/ Control, Balance, Supply & Delivery Ports* High Quality Spring Brake Valve* SR7 Type Spring Brake Modulating Valve* Ports:  - (2) 1/4 Inch NPT Control Ports  - (1) 1/4...
    09-05170499
    SKU:
    09-05170499
    Product Type:
    Air, Electrical, & Safety
    Make:
    Universal Items
    $155.99
    Qty in Cart: 0
    Price:
    $155.99
    Subtotal:
  • FREE SHIPPING OVER $249
    Spring Brake Control Valve W/ 3/8 Inch NPT Control Support & 3/8 Inch NPT Supply Port Replaces 170.110170

    Spring Brake Control Valve W/ 3/8 Inch NPT Control Support & 3/8 Inch NPT Supply Port Replaces 170.110170

    AFTERMARKET

    $86.99
    Spring Brake Control Valve W/ 2 - 1/2 Inch NPT Reservoir Ports & 4 3/8 Inch NPT Delivery Ports* High Quality Spring Brake Valve* Protected Reservoir Spring Brake Control Valve* Control And Supply...
    09-05170490
    SKU:
    09-05170490
    Product Type:
    Air, Electrical, & Safety
    Make:
    Universal Items
    $86.99
    Qty in Cart: 0
    Price:
    $86.99
    Subtotal:
  • FREE SHIPPING OVER $249
    TP3 Type Tractor Protection Valve Rear Mounted Replaces 170.279000

    TP3 Type Tractor Protection Valve Rear Mounted Replaces 170.279000

    AFTERMARKET

    $26.99
    TP3 Type Tractor Protection Valve W/ .35 Inch Mounting Hole* High Quality Tractor Protection Valve* TP3 Type Tractor Protection Valve* Trailer Ports Are Both 1/2 in. NPT* Protects Tractor Air Supply...
    09-05170484
    SKU:
    09-05170484
    Product Type:
    Air, Electrical, & Safety
    Make:
    Universal Items
    $26.99
    Qty in Cart: 0
    Price:
    $26.99
    Subtotal:
  • FREE SHIPPING OVER $249
    Dash Valve MV3 Type Dash Control Module W/ Integral Push-Lock-Connect Fittings Replaces 170.800260, 170.800260WF

    Dash Valve MV3 Type Dash Control Module W/ Integral Push-Lock-Connect Fittings Replaces 170.800260, 170.800260WF

    AFTERMARKET

    $133.99
    Dash Valve 4.22 X 3 Inch C To C W/ 4 M5 X .8 - 6H Mounting Holes* High Quality Dash Valve* MV3 Type Dash Control Module With Integral Push-Lock-Connect Fittings* Operating Temp From -40 To 200...
    09-05170485
    SKU:
    09-05170485
    Product Type:
    Air, Electrical, & Safety
    Make:
    Universal Items
    $133.99
    Qty in Cart: 0
    Price:
    $133.99
    Subtotal:
  • FREE SHIPPING OVER $249
    BPR1 Type Brake Proportioning Relay Valve W/ 4 PSI Crack Pressure Replaces 170.065145

    BPR1 Type Brake Proportioning Relay Valve W/ 4 PSI Crack Pressure Replaces 170.065145

    AFTERMARKET

    $63.99
    BPR1 Type Brake Proportioning Relay Valve W/ Control, Service, Supply & Delivery Ports* High Quality Relay Valve* BPR1 Type Brake Proportioning Relay Valve* 4 PSI Crack Pressure* Mounting Bracket...
    09-05170495
    SKU:
    09-05170495
    Product Type:
    Air, Electrical, & Safety
    Make:
    Universal Items
    $63.99
    Qty in Cart: 0
    Price:
    $63.99
    Subtotal:
  • FREE SHIPPING OVER $249
    TP3DC Type Tractor Protection Valve W/ Double Check Valve Replaces 170.065706

    TP3DC Type Tractor Protection Valve W/ Double Check Valve Replaces 170.065706

    AFTERMARKET

    $80.99
    TP3DC Type Tractor Protection Valve W/ Primary, Secondary, Switch & Supply Ports* High Quality Tractor Protection Valve* TP3DC Type Tractor Protection Valve* Contains Double Check Valve* Ports:  -...
    09-05170486
    SKU:
    09-05170486
    Product Type:
    Air, Electrical, & Safety
    Make:
    Universal Items
    $80.99
    Qty in Cart: 0
    Price:
    $80.99
    Subtotal:
  • FREE SHIPPING OVER $249
    D2 Type Governor W/ Gasket, 3 Plugs & ADIS Type Check Valve Kit Replaces 170.5004049

    D2 Type Governor W/ Gasket, 3 Plugs & ADIS Type Check Valve Kit Replaces 170.5004049

    AFTERMARKET

    $42.99
    D2 Type Governor W/ 105 PSI Cut-In & 125 PSI Cut-Out* High Quality Governor* D2 Type* Operating Temps From -40 To 200 Degrees Farenheit* 105 PSI Cut-In* 125 PSI Cut-Out* Non-Adjustable* Used In ADIS...
    09-05170480
    SKU:
    09-05170480
    Product Type:
    Air, Electrical, & Safety
    Make:
    Universal Items
    $42.99
    Qty in Cart: 0
    Price:
    $42.99
    Subtotal:
  • FREE SHIPPING OVER $249
    MV3 Type Dash Valve Control Module W/ 5 - 3/8 Inch PLC Ports Replaces 21315044, 21750583

    MV3 Type Dash Valve Control Module W/ 5 - 3/8 Inch PLC Ports Replaces 21315044, 21750583

    AFTERMARKET

    $209.99
    MV3 Type Dash Valve Control Module W/ 3.5 X 4.2 Inch C To C* High Quality Dash Valve* MV3 Type Dash Control Module* (5) 3/8 Inch PLC Ports* Dimensions:  - 3.5 Inch Center To Center Width  - 4.2 Inch...
    09-05170491
    SKU:
    09-05170491
    Product Type:
    Air, Electrical, & Safety
    Make:
    Universal Items
    $209.99
    Qty in Cart: 0
    Price:
    $209.99
    Subtotal:
  • FREE SHIPPING OVER $249
    Dash Valve MV3 Type Dash Control Module W/ Integral Push-Lock-Connect Fittings Replaces 170.802122, 170.802122WF

    Dash Valve MV3 Type Dash Control Module W/ Integral Push-Lock-Connect Fittings Replaces 170.802122, 170.802122WF

    AFTERMARKET

    $123.99
    Dash Valve W/ 4 - 3/8 Inch PLC Ports & 1/2 Inch PLC Exhaust Port* High Quality Dash Valve* MV3 Type Dash Control Module With Integral Push-Lock-Connect Fittings* Auxiliary Port Not Existent* Trailer...
    09-05170482
    SKU:
    09-05170482
    Product Type:
    Air, Electrical, & Safety
    Make:
    Universal Items
    $123.99
    Qty in Cart: 0
    Price:
    $123.99
    Subtotal:
  • FREE SHIPPING OVER $249
    RG2 Type Relay Valve W/ .35 Inch Diameter Mounting Bracket Holes 1.5 Inch C To C Replaces 170.KN28500

    RG2 Type Relay Valve W/ .35 Inch Diameter Mounting Bracket Holes 1.5 Inch C To C Replaces 170.KN28500

    AFTERMARKET

    $38.99
    RG2 Type Relay Valve 5.6 PSI Crack Pressure W/ Control, Reservoir & Deliver NPT Ports* High Quality Relay Valve* RG2 Type Relay Valve* 5.6 PSI Crack Pressure* (2) 0.35 Inch Diameter Mounting Bracket...
    09-05170487
    SKU:
    09-05170487
    Product Type:
    Air, Electrical, & Safety
    Make:
    Universal Items
    $38.99
    Qty in Cart: 0
    Price:
    $38.99
    Subtotal:
  • Total: items /

Adding your products to cart

Semi Truck Gladhands & Air Connections

A semi truck gladhand is the critical connection point between your tractor air lines and the trailer’s air-brake system. These heavy-duty couplers lock together with a rubber seal to hold air pressure securely. Our inventory helps you restore and replace your existing gladhand configuration when it’s cracked, leaking, corroded, or damaged. Semi Truck Gladhand Replacements: Replace worn or damaged tractor-trailer air couplers to restore a tight, reliable air connection. Service Gladhands: Blue service gladhands carry control air used to apply the trailer brakes during normal braking. Emergency Gladhands: Red emergency gladhands supply constant air pressure to the trailer and keep the emergency spring brakes released while driving. Gladhand Seals and Replacement Parts: Replace cracked, flattened, hardened, or leaking seals when the gladhand body and locking tabs remain in good condition. Air Lines with Gladhands: Find 2-in-1, 3-in-1, ABS, and power air lines to replace chafed, cracked, stretched, or worn tractor-trailer connections.

Signs of a Leaking Gladhand

Replace or inspect the gladhand when you notice hissing, air-pressure loss, frequent compressor cycling, slow air recovery, visible seal damage, or air leaking at the tractor-trailer connection.

Gladhand Seals vs. Complete Couplers

Replace the rubber seal when the coupler body is solid but the gasket is worn, cracked, flattened, or leaking. Replace the complete gladhand when the body, locking tabs, threads, or sealing surface is damaged or badly corroded.

Individual Gladhands vs. Complete Air-Line Assemblies

Individual gladhands make sense when your hoses remain in good condition and only the coupler needs replacement. Complete air-line assemblies replace the hoses and connections together. Choose them when lines are cracked, weathered, stretched, damaged, or due for replacement.

Air Brake Valves & Controls

We stock tractor-trailer air-brake protection valves, quick-release valves, emergency relay valves, and MV3 dash valves. Replace worn PP5 and PPDC control valves, trailer brake valves, and related spring brake components to restore proper air-brake control.

Air System Maintenance & Repair Parts

Maintain and repair your air system with air dryers, air solenoid valves, air hoses, fittings, and air tank hardware. Emergency air-brake and in-cab air-line repair kits also help address damaged lines and fittings during roadside repairs.

Trailer ABS & Electrical Connections

Keep tractor-trailer air and electrical connections organized with ABS cables, 7-way electrical cords, wrapped hose assemblies, air-line boxes, and pogo sticks. Replace worn or damaged connection hardware to protect air lines, power cords, and ABS wiring from dragging, chafing, and road damage.

Frequently Asked Questions About Semi-Truck Safety, Air & Electrical

What air pressure switches and valves are compatible with my specific truck model?

Compatibility depends on your truck's make, model, and year. Most Freightliner Cascadia models (2008-2023) use standard 1/4" NPT air pressure switches rated at 90-120 PSI. Peterbilt 579/389 models typically require 1/8" NPT connections. Kenworth T680/W900 models often use proprietary valve configurations. Always check your truck's service manual for exact specifications, or contact our technical support team with your OEM for precise matching.

How difficult is it to install safety lighting and electrical components myself?

Installation difficulty varies by component. LED marker lights and basic warning lights typically require 30-60 minutes with basic tools and can be DIY-installed by following color-coded wiring (white=ground, black=power). Air horns and pressure gauges require air line connections and may need professional installation to avoid leaks. Complex items like backup cameras or multi-circuit lighting systems often require 2-4 hours and intermediate electrical knowledge. We provide detailed installation guides with each product, and most customers report successful DIY installation for basic components.

What's the actual lifespan of LED safety lights versus traditional bulbs in real-world conditions?

Based on customer feedback and warranty data, quality LED safety lights last 30,000-50,000 hours of operation, which translates to 5-8 years of typical commercial use. Traditional incandescent bulbs average 1,000-2,000 hours (6-12 months). LEDs handle vibration better and maintain brightness longer. However, cheaper LED units may fail within 1-2 years due to poor heat dissipation or inadequate weatherproofing. We recommend DOT-certified LEDs with aluminum housings and IP67 or higher waterproof ratings for maximum longevity.

Which air brake components fail most frequently and what are the warning signs?

The most common failures occur in air dryers (every 2-3 years), pressure protection valves (3-4 years), and gladhand seals (annually). Warning signs include: air dryer constantly purging or not purging at all, slow air pressure build-up taking over 3 minutes to reach 90 PSI, air leaks audible when brakes are released, and moisture in air tanks. Quick-release valves often stick in winter conditions. Regular maintenance with quality replacement parts can extend component life by 30-50%.

What gauge and type of wiring should I use for adding auxiliary lights and accessories?

Wire gauge depends on the accessory's amperage draw and cable run length. For LED marker lights (0.5-2 amps), use 18-16 AWG wire for runs under 15 feet. Work lights and fog lights (3-10 amps) require 14-12 AWG wire. High-powered LED light bars (15-30 amps) need 10 AWG wire with inline fuses. Always use automotive-grade stranded copper wire with SAE J1128 rating for flexibility and heat resistance. Install proper fuses or circuit breakers rated at 125% of the accessory's amp draw. Avoid household solid-core wire as it becomes brittle and cracks from vibration.


Introducing the Official 4 State Trucks Mobile App – Gear Up On the Go!