Seneca Air Parking Brake question

[dmall]

Know the 2013?-2015 have a air parking brake with the warning label on the dash about chocking the wheels. Do you have to chock the wheels every time you park the rig? For those that own one of these year models, what's your practice and experience with chocking wheels? Thanks in advance

[Mountain Cajun]

I haven’t chock the wheels. First thing I do is put the jacks down then shut the engine down. When departing, I always crank the engine to build air pressure. Then raise the jacks. Building air pressure lock brakes back.

[Robbbyr]

On the pre-air brake Senecas the air parking brake is actually a driveline brake, acting to lock the driveshaft instead of the actual rear drum brakes like the air brake models do. But like the spring parking brakes on an air brake-equipped coach, our driveline brake is also applied by a heavy spring when the air is released from the brake chamber and the brake is released when air pressure is restored (by the dash valve) to the release chamber. So a total loss of air, like in later Senecas, will cause the rear tires to be locked.

As far as the use of wheel chocks, many references will recommend chocking the wheels on any large vehicle when parked, especially on any grade. Even cars with automatic transmissions will tell you to also apply the parking brake even though their transmissions have a parking pawl to prevent movement. Despite our Senecas having a "P" position on the shifter our Allison transmissions do not have a parking pawl, so the driveline brake is the only thing preventing our Senecas from rolling. And any brake can get out of adjustment or fail to the point the unit could roll. Jayco and/or Freightliner was just protecting their liability with the warning label.

Do I chock my wheels everytime? No. Do I chock them on sites where I think leveling could cause the rear tires to unload some or even come completely off the ground? Very big yes! One thing Bigfoot (my levelers manufacturer) told me to try to do is avoid lateral pressure on the jacks. So I try to prevent any forward or backwards rolling when going up or coming down off the jacks.

[dmall]

Thank you ! Helps me understand !

[RVermont]

I too only chock the tires when on a slope and going to use the level Jack's. As the slope and unevenness of the ground gets greater the chocks get more important. I also try park front end low. This combined with dumping my air bags allows the rear end to stay firmly on the ground. If needed I will put front tires onto level blocks.