Frequently Asked Questions
- General Questions
- Our Valve/Delco Valve
- Service Questions
- Valve Identification and Purchasing Questions
- Valve Application Questions
Q: What does a Height Control Valve do?
A: Height Control Valves maintain an air suspension at constant height regardless of load. When the load on an air suspension system is reduced, the air springs (or shocks) will lift the vehicle in response to the lightened load. When the load is increased, the air springs will be compressed and the vehicle will lower. A Height Control Valve in the air spring circuit will allow air to enter or leave the air springs as needed in order to maintain constant height. We have a more in-depth description here.
Q: Is this the same company that made the original Delco height control valves?
A: Yes. We have made the valves and links since 1981.
Q: How do I know if I have a genuine King of the Road (Delco) valve?
A: Since 2003 "King of the Road” (our trade name) and "Dayton OH” have been cast into the valve body next to the mounting bracket. Older valves made before 1990 had the Delco name in this same location. Unfortunately the period in between these dates had no marking other than the part number located on the Control Arm.
Q: How can I tell if my valve is an original King valve?
A: All King Valves have a raised ‘KING OF THE ROAD’, cast directly into the valve body. Legacy valves will have ‘DELCO PRODUCTS’ cast directly into the body. Absence of the cast name indicates an inferior counterfeit valve. These counterfeit valves have not passed rigorous Delco/King of the Road testing and calibration requirements.
Q: Why should I purchase your valves when I can get a foreign made replacement for less money?
A: Our research shows that these copy-cat valves are not made exactly like our valves. We have had customers tell us that they are getting as little as nine months of service life using these parts and it is driving up their service costs.
Q: What vehicles were Delco valves used on?
A: The original Delco valve was developed for air suspension on 1959 Cadillacs. The use of air spring suspensions extended to most GM marques, being more common on luxury models. The valve also saw heavy use on GMC transit buses, Ford and Mack trucks, and many makes of semi-trailers. In the late 1970s the valves were used on air shock suspensions for GM cars.
Q: My valve has stopped working, now what?
A: Please check out our Troubleshooting page here.
Q: Do you have installation Instructions?
A: We have installation instructions here.
Q: Do you have Troubleshooting Info?
A: We have troubleshooting info here.
Q: Do you have maintenance info?
A: We have basic maintenance info here.
Q: I have an air leak in my system, should I replace the valve with a new one?
A: It is unusual to find one of our valves that leak. 100% of our valves are tested to a leak rate of 2sccm which is less than an acceptable leak from one air spring. We always suggest checking the fittings for proper tightness and air lines for crimps or cuts before removing the valves.
Q: Do I need to install a check valve to prevent the air system from bleeding down when the air compressor is not running?
A: Unlike our competitor's products most of our valves come with a check valve on the air inlet. When the air pressure drops on the air compressor side of the Leveling Valve this check valve will keep the air in the springs or shocks from flowing back towards the compressor, preventing deflation of the system.
Q: I would like to repair my Delco height control valve. Can I purchase a rebuild kit from you?
A: We no longer sell the internal components necessary to completely rebuild a valve. We do sell kits that include the various air fittings, seals and check valves that are required for valve installation.
Q: Do you have Teardown or Repair information?
A: We do not offer teardown or repair information on our site. All KOTR valves are sold with a 30 month/100,000 mile warranty and should be returned for warranty consideration within this time period. If you have an older valve and would like further information on possible repair or replacement, please contact us here.
Q: I need to purchase a new valve, where can I find the part number?
A: Our part number is located on the gold colored Control Arm mounted on the side of the valve.
Q: How can I buy a replacement valve for my car or truck?
A: We currently sell through our distributor network. Please see our distributor contact page here.
Q: I have a 1983 MCI 9 Bus - what is the part number for my leveling valve?
A: Unfortunately we do not have any way to look up which of our parts were used on a particular vehicle. You will need to look up the part number in the vehicle parts manual or check directly with the manufacturer. We can usually cross reference the OEM part number back to ours.
Q: Do you make special or modified valves?
A: We can engineer valve modifications and custom mounting configurations. For more information, please see our Custom Valve page here.
Q: Can you make a replacement valve for my vintage Cadillac?
A: We have many legacy Delco drawings in our database and have produced replacement valves for several older vehicle makes, including GMC, Cadillac, Chevrolet, Ford, AMC, and others. If you can provide detailed pictures of the valve and application, we can let you know if we have or can make your valve.
Q: Do you have replacement valves for my GMC Motorhome?
A: Yes, we do still manufacture the GMC Motorhome valve. This valve is available through several of our distributors, listed here.