Sealant is not allowed on vacuum hoses or vacuum lines.
The California smog inspection process requires that vacuum lines and hoses be replaced when needed. Using sealant to repair a vacuum line, when the vacuum line pertains to the vehicle's emissions system, will cause the smog technician to mark the particular emissions system to which the vacuum line or hose belongs as tampered and/or defective.
Why am I not allowed to repair a vacuum line?
Often repairs of vacuum lines and hoses are not made to withstand the California Air Resources Board's stringent heat and durability requirements. Once a vacuum hose has development a problem needing repair, the CARB suspects the vacuum line has reached its service life capacity and requires the component replacement. It is not uncommon to see more failing vacuum hoses when one is detected, especially in high heat engine compartment locations.
What's the remedy to repair a vacuum hose and pass the smog test?
If you're considering repairing as in replacing... then you'll be fine. Vacuum lines and hoses are commonly replaceable with aftermarket inexpensive counterparts. For the price of sealant you may be able to purchase several feet of vacuum line. Ensure to purchase the correct diameter for your replacement. It is pertinent that vacuum lines and hoses seal air/vacuum tightly at all connection points.
posted by SmogTips Support 07-25-2017 06:10 PM