Proper Inflation of the Curt Flex Air 5th Wheel Pin Box
Updated 08/27/2025 | Published 06/02/2022 >
Question:
I have a Trailair Flexair 18,000 gvrw pin box and have been inflating to 70 psi My question is - do you inflate the airbags when they are under load hooked up to the fifth wheel with landing gear up or when not loaded. The coach seems to ride well at 70 psi- is that the proper inflation? Thanks
asked by: Ted K
Expert Reply:
The Flex Air 5th Wheel, # LC328492 is to be inflated to between 20 and 120 psi. The pressure that works best for your specific arrangement and the current load is what determines the best pressure. Trying several different pressure setting and evaluating the ride quality is the way to make determination. Always maintain at least 5 psi in the system when not in use. You can inflate before or after making connection.
Product Page this Question was Asked From
Curt Flex Air 5th Wheel Pin Box - Lippert 1621 - 18,000 lbs
- 5th Wheel Pin Box
- Upgraded Pin Box
- Absorbs Road Shock and Reduces Chucking
- 18000 lbs
- Air Ride Suspension
- Fixed Turret
- Lippert 1621
- CURT
more information >
Continue Researching
- Search Results: 5th wheel pin box
- Search Results: air ride suspension 5th wheel pin box
- Search Results: trailer hitch
- Shop: Curt Flex Air 5th Wheel Pin Box - Lippert 1621 - 21,000 lbs
- Shop: Curt Flex Air 5th Wheel Pin Box - Lippert 1621 - 18,000 lbs
- Video: Curt Flex Air 5th Wheel Pin Box Review
- Q&A: What Model Lippert Pin Box Do I Have?
- Video: Setting up the Curt Flex Air 5th Wheel Pin Box on your 2007 Starcraft Homestead Lite Fifth Wheel
- Q&A: Air Pressure Range for a TrailAir Flex Air 5th Wheel Pin Box
- Shop: Dutton-Lainson Covered Hand Winch - Single Speed - Freewheel - 20' Strap - 1,500 lbs
- Shop: Dutton-Lainson Covered Hand Winch - Single Speed - Freewheel - 20' Strap - 1,900 lbs
- Q&A: How To Determine The Correct PSI For A Trailair Air Ride Pin Box For A Smoother Ride
- Shop: Replacement 110-Volt AC Fan Motor for Ventline RV Bathroom Insert Fan w/100 CFM Capacity
- Q&A: What is Minimum Air Pressure for Curt Flex Air Pin Box
- Q&A: What is the Difference Between a Class II and a Class III Hitch?
- Shop: Power Mountain Tallboy Off-Road Bottle Jack - 8-1/2" to 37-3/4" Lift - 6 Tons
- Video: Firestone Ride-Rite Air Bags with Easy Mount Compressor Feature Breakdown
- Article: Trailer Wiring Diagrams
- Shop: Trailer Hitch
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
- Shop: Trailer Wiring
- Shop: Curt Powered Tail Light Converter with 4-Pole Flat Trailer Connector
- Q&A: Lug Nut Torque Chart for Trailer Wheels
- Search Results: trailer wiring
- Article: 4 Steps to Choosing Your 5th Wheel Pin Box
- Q&A: Installation Time for Blue Ox BX1128 Flat Tow Base Plate Kit for 2016 Jeep Grand Cherokee
- Video: B&W Companion OEM 5th Wheel Hitch Manufacturer Breakdown
- Shop: Suspension Enhancement
- Search Results: trailer tires and wheels
- Search Results: trailer suspension parts


Tom B.
8/27/2025
They can bottom out so make sure you don’t under inflate.