Seneca article 12/17

[RodgerS]

Seneca 37HJ

[RodgerS]

Very useful comment regarding the air-ride seats: "Bumps and vibrations not handled by the suspension are controlled by the air-ride cockpit seats. Although the macho-truck look provoked initial thoughts that the ride was going to be less than stellar, even with the advanced suspension, a few minutes down the highway and then on to uneven curved backcountry roads confirmed that it was ultimately a winning combination, supplying a smooth ride during road transitions and exhibiting very limited body roll."

[RodgerS]

Does anyone know yet if the air-ride seats could be installed on older versions and at what cost?

[norty1]

That's a sweet rig! I have a buddy who has a older M2 with the air ride seats so they have been around a while.

[mikew968]

Air ride seats are new to 2016 along with air brakes and a macerator on the waster water system.

[RodgerS]

That's what I thought Mike. Pretty hard, as I understand it to put in air brakes after market, and somewhat problematic on the air ride seats as I understand it. So, there is a pretty good argument for new 2016 technology wise...drat...just less to leave to my heirs if I don't go with a used premium A.

[Robbbyr]

Has anyone heard why Jayco changed to an air brake-equipped chassis? I own a 2014 TS with "juice" brakes and have never been concerned about the performance of my hydraulic brakes, nor heard anyone else owning a Seneca complain about their brakes. And does anyone know if Jayco uses 4-wheel air discs on the '16 models, or did they take the less expensive route of using air drum brakes?

As far as the new seats, I'm afraid if the ride was much smoother I might doze off at the wheel! Coming from the very "busy" ride of my former Ford-based Class C units, the ride of my Seneca is so much better and I am very happy.

Maybe they are trying to attract former DP owners who are accustomed to these features?

[LSA376]

I've never been impressed with the hydraulic brakes in our Seneca, seems like I need the engine brake to slow and stop the unit especially if towing the trailer. I added the front Bilstein shocks as they made a huge difference in ride quality and handling. Non air seats seem fine to me, as the new ones don't get the matching fabric as the rest of the interior, only seat color is grey. Don't understand that one...

[Robbbyr]

When I last went to the CAT scale I was towing my '14 Explorer and my GCWR was just a tad over 29K, the coach alone was around 24K. Full water, fuel, propane, provisions, DW, and two grandsons. Is your combination weight greater with your trailer? Have you had an opportunity to drive a new Seneca to see whether or not the air brakes improve how it brakes? It may matter more as one gets closer to the maximums.

And regarding the air seats, if indeed they are not available in a matching covering I am with you with in preferring seat fabric that complements the rest of the interior.

I still would like to install air horns as compared to the wimpy electric one on my unit, anyone know if they made that upgrade on the new units?

[LSA376]

Robby, I weighed the Seneca just as you did, full weight watered and loaded 23K and change. The trailer I tow comes in around 7,700lbs depending on the trip. I live at 3,400' elevation with a 3.5 mile grade that varies between 6 and 12% just leaving my association. Thank God for the engine brake! I've thought of performing a brake fluid change and bleed to attempt better braking as they just don't seem right. The new air brakes are drum, not sure of the performance of them however, I'm going to test drive a '16 just to feel the difference. I'll report back after the drive.

[RodgerS]

"Maybe they are trying to attract former DP owners who are accustomed to these features?"

As I see it...

I think that is likely, as more experienced owners look at these units differently. If you are frustrated with the high repair costs and the access awkwardness of the rear engine dp, and the lack of up front impact safety on an A, and desire a more traditional/transitional driving experience, a premium C becomes "potentially" attractive to those owners who are on the upper end of miles and time on the road and are not bling status oriented.

There is a trend towards downsizing now, even into a B unit.

Prior dp owners would like to have at least some of the options, amenities, and benefits available in a Seneca that they had in a dp. A less beat you down ride is important and that means the suspension is important.

Myself, I have a mental problem with a B, as it is so confining I don't think I could do the longer trips I intend to do. I'm not convinced the gas C and shorter gas A's are gonna work at my age...I get worn down much easier these days and same with a truck pulling a 5th or tt...just don't want a truck for my daily driver...compared to my Mercedes.

So, a shorter premium used A or a new/newer Seneca provides me two potential ranges of options that I appreciate having with under $200k or under $100k budgets depending on what I decide to "invest cash in" at the end of the day.

[LSA376]

Agree 100%. Just as you stated, the push for the Super C for me was the engine access and safety in addition to the driver/passenger doors and driving experience. I also like the fact that if something happens with the drivetrain I can hear it unlike the DP.

[rgolding]

Nice article about a good product.

[Robbbyr]

Originally Posted by LSA376

The new air brakes are drum, not sure of the performance of them however, I'm going to test drive a '16 just to feel the difference. I'll report back after the drive.

In my many years of driving fire trucks for a living I saw the introduction of air disc brakes into those applications. Now my (former) department only buys disc brake-equipped trucks (when available) since we felt they performed better and were much easier to inspect and service. And my department is an urban department in a hilly area where brakes take a real beating. Disc brakes are proven to last longer and hold up better in severe-service applications. I am not saying air drum brakes are bad, they serve reliably on millions of vehicles on the road right now. Federal regulations forced the truck manufacturers to improve the stopping distances of large trucks over time, and generally the air drum systems got larger components to meet that requirement. But in general disc brakes worked better albeit at a somewhat higher initial cost.

I hope Jayco made the change for the right reasons and not just to save a few bucks. My hydraulic 4-wheel disc brake chassis has the exact same air compressor as installed on the new air brake-equipped units. But my air system only serves the air parking brake, cooling fan, and rear suspension. Having gone that far maybe it is less expensive to go the rest of the way and install air brakes rather than the hybrid design older Senecas have.

But without more definitive data I don't know if I personally would want 4-wheel air drum brakes over my 4-wheel hydraulic disc brakes I have now.

[RodgerS]

Food for thought Rob.

[gtsum2]

I believe the toy hauler will go for sale next year and the 37hj is the lead candidate. Good article

[RodgerS]

Found an article on brakes Air Brakes or Hydraulic Brakes: That is the Question - Articles - Maintenance - Articles - Work Truck

Below are quotes pulled out:

What brake system is more appropriate for a medium-duty truck's size and duty cycle?...In most cases, hydraulic brakes are used on trucks up to 26,000-lbs. GVWR.

(my note: Seneca GVWR 28,000 lbs)

"Todd Kaufman, F-Series chassis cab marketing manager for Ford Motor Company, draws the line between hydraulic and air brakes based on a truck's duty cycle, stops per day, and payload requirements. "In the lighter applications from 19,501 lbs. to 26,000 lbs., hydraulic brakes do well to serve the market. You might even stretch it as high as 29,000 lbs.; but, usually, when going above 26,000 lbs., loads are substantially heavier, which may overload the hydraulic brakes, causing them to wear sooner and diminish stopping performance," he said."

Applications: Moore recommends air brakes for heavy vocational applications and noted they should always be used in heavy towing applications."

A significant reason why air brakes are preferred in heavier trucks (above 26,000-lbs. GVWR), compared to hydraulic systems, is their robust stopping power when they work - and when they fail. For example, if there's a leak in the brake line of an hydraulic system, fluid pressure can lower to the point where there isn't sufficient force on the brake pads to create the friction needed to slow the wheel. Eventually, if the leak is not repaired, the truck can lose braking power in that portion of the system, reducing the ability to stop in the same distance. With air brakes, the opposite happens. If there is a leak in the air brake lines, the air pressure decreases, which actually activates the brakes at the wheels and brings the vehicle to a safe stop.

However, air brakes come at a premium price. According to Kaufman of Ford, the air brake system costs approximately $2,500 more than hydraulic brakes, because of the extra components to operate the system. "When you compress air, you have moisture, and you have to get rid of that moisture so you're adding air dryers as part of the initial purchase. But, if you're going to keep the vehicle for more than five years - maintenance costs tend to go more vertical after year five and get really expensive. After that, I think air brakes pay for themselves," he said.

Another factor with air brakes is how they impact a fleet's available driver pool. Even if the truck is under 26,000-lbs. GVWR, which would normally not require a commercial driver's license (CDL) to operate, if it is equipped with air brakes, the driver may have to carry a CDL, depending on the state's laws, which limits the number of drivers qualified to operate the truck.

"Air brakes, for lack of a better description, are either 'on' or they are 'off.' If you've never driven an air brake truck, the first few times you press the brake, you feel like you're putting yourself through the windshield. Unlike hydraulic brakes, which modulate more intuitively, the operator has a lot to do with actively modulating the air brakes to make the stopping process smoother. That's something the driver learns," Kaufman noted.

[Robbbyr]

I can see the logic in that information, however there is what I believe an error in part of the information regarding the failure mode.

Air brakes will only fail in the "apply" position on the axles equipped with spring parking brakes. That is generally only the drive (rear) axle. Those axles have dual air chambers, one chamber contains a very heavy spring that forces the brakes "on" when there is no air in that chamber. That happens when you apply the parking brake (the "whoosh" you hear of the air exhausting) or if their is a major problem causing a total loss of air pressure. The second chamber in those assemblies is what normally "applies" the brakes based on driver input from the brake treadle valve.

Only axles equipped with spring brakes will have braking when there is a loss of air or the parking brake is applied. Steer axles will only brake when air is applied during normal braking. If there is a failure, no front brakes on big trucks either! The parking brake does nothing to hold the front brakes "on" either.

To complicate matters, for the spring brakes to be effective the brake shoes/pads, drums/rotors, and slack adjusters have to all be in good shape or you won't have effective parking brakes. Anything amiss and the truck can roll. And believe me it won't stop it much at all if you have momentum with anything out of order.

We trained our firefighters extensively on air brake operation so they understood the peculiarities, including applying the parking brake manually driving down the road. At about 25 mph the truck would stop about 200 feet or more down the road. Far, far further than if you used the service brakes.

I renew my plea to anyone with air brakes on their coach to ensure they understand how they work, and how they can fail if you use them improperly. You can deplete your air if you don't know what you are doing and then you are in real trouble. CDL training can educate you on air brakes, but most states do not require CDL for RV drivers. This has been hashed out in these forums before where I got on my soapbox there too!