Re: [A/S] Vacuum Disc Brakes

[Charlie/Betty Burke <cbburke@xxxxxxxxxxxxx>]

Kevin,

When it was introduced the Excella-Vac brake system was the most 
sophisticated and effective trailer brake system built. And until the 
new generation disk brake systems which are just recently being 
introduced there was nothing that approached it in performance. The 
system was so effective that when installed on the first triple axles it 
was not necessary to put brakes on the third axle.
When purchasing a trailer with this system on it it is necessary to 
retrieve the parts associated with it off the tow vehicle. In particular 
the vacuum fittings at the rear and the T and check valve mounted in the 
power brake vacuum booster in the engine compartment.
This system is not compatible with modern diesel engine tow vehicles 
because it relies on engine vacuum to operate. It would be necessary to 
install a vacuum pump to properly operate it.
The brake controller, made by Midland, was unique at the time. We found 
that current high output proportional brake controllers will work.
The brake actuator mounted on/in the trailer required periodic 
maintenance which history has shown did not get done in many cases. In 
these instances water got into the exacting machined parts and seized them.
Parts availability has been limited almost since they went out of 
production in the mid '80s. The last known source is Inland RV in 
Corona, CA.
Most dealers will recommend replacing the system with electric brakes. 
This conversion runs $1500-2500 depending on where you get it done.
Having the Excella-Vac brake system is not generally considered a plus 
these days due to the potential expenditures associated with either 
keeping it or changing it out.

Charlie