Air Over Hydraulic Brakes?

[jbrunson]

Still trying to educate myself here.... last couple I looked at had "Air over hydraulic brakes" I have researched all of the theory... now to the practical. How practical is this? Are parts easy to get? Would it be easier in the long run to just get a coach with air brakes?

[wolfe10]

With very rare exception, brakes on motorhomes are NOT unique-- they are off the shelf parts used on trucks.

I have had both "air drum brakes" and two coaches with "hydraulic over hydraulic disk brakes-- one with floating calipers and one with 4 piston calipers"

All three have done a great job.

Not familiar with "air over hydraulic brakes". What coach/what chassis?

[desertdeals69]

I use to have air over hydraulic brakes on my Spartan chassis. It had disc brakes and the two master cylinders were air operated and the air diaphragms would push the hydraulic master cylinder. I have since replaced them with full air brakes. I did take one of the air/hydraulic cylinders and install it on my tow dolly so I would have air brakes on it.

[rossboyer]

I had air over hydraulic brakes on a Harney Coach Renegade produced by SMC on a Magnum chassis. Safari and Beaver used the same chassis. I liked the braking much better than the air brakes I have on a Freightliner chassis on our current motor home. The air over hydraulic has feel that is closer to an auto. Where as you need additional braking, you push harder. The air brakes I now have, you have to hit hard first and then ease off. Just me, I like the feel of the air over hydraulic.

PS: Some call this system Air Over Oil.

[wolfe10]

Ross,

Are you sure it was not hydraulic over hydraulic? That was the system used on most of the Magnum chassis/Safari Corp coaches in that era.

The same hydraulic pump supplied: power steering, power brakes, parking brake release.

[rossboyer]

I was told it was air over hydraulic, but I sold it in 2008, so I am not positive. I do know the power steering was a separate system.