I installed a VIAIR on-board air system on my SMB less than 6 months ago and has barely been used. This system is not worth the money or time. Here are the key problems:
1) the threads on the ports on the 2.5 gallon tank are painted. If you do not tap the threads clear of paint, they will leak air. NO matter how much sealent or tape is used, the ports will leak. I've spent HOURS trying to fix the leaky ports - highly frustrating.
2) the relief valve and water dump valve are of poor quality. The relief valve has already failed and requires replacement
3) VIAIR does NOT stand behind their product. VIAIR directed me to a retailer to purchase replacement parts.
Bottom line, the system is designed poorly, uses low quality parts and is not supported by the manufacturer.
2000 EB50 Q4x4 7.3PSD