Using Electric Over Hydraulic Trailer Brake Actuator on Airstream Trailer With Excella Vacuum Brakes

Question:

Good morning, We just purchased an Airstream equiped with the excella vacuum brakes. I believe that we might be able to use the Carlisle HydraStar Electric-Hydraulic Actuator for Disc Brakes product. Since we are connecting it to a 2008 Chevy Tahoe, Im guessing we might also need the Adapter Module for HydraStar Electric-Hydraulic Brake Actuators. Will this system work for our trailer? Thank you

asked by: Matt

Expert Reply:

From what I've read online, in its day, the Airstream Excella vacuum braking system worked very well, but at this point, they're obsolete. Replacement parts are difficult to find and the parts that would need to install on the vehicle aren't readily available.

I saw several references in the forums to folks who simply changed their brakes to an electric drum system, which would be your least expensive option. If you wish to go this route, I'd need to know your inner and outer bearing reference numbers and the reference number of the grease seal you're using. If you cannot get the numbers off the bearings and the grease seals, you can use a digital caliper to get the diameter of the spindle surface where the inner and outer bearings ride. For the grease seal, I'd need the diameter of the hub bore where the seal sits, plus the diameter of the surface of the spindle where the seal rides. I'd also need to know the wheel bolt pattern (number of lugs and bolt circle) of your existing wheels.

Some folks switched to an electric over hydraulic system, but I wasn't able to find much in the way of details about that. You could use the Carlisle Hydrastar # HBA16 but you'd most likely need to replace the existing brake lines with a set like # DM5425. This of course assumes that your existing brake pads, rotors and calipers are still in good shape. If the calipers and rotors need replacing, I'd need the bearing/seal numbers.

You'd then need to install a brake controller in your Tahoe that is compatible with electric over hydraulic systems like the Tekonsha Prodigy P2, part # 90885. The Prodigy would also be my choice to actuate an electric brake system. If your Tahoe is equipped with the OEM GM brake controller, you'd need the # HBA-CAM Control Adapter Module in order for the controller to work with the actuator.

The HBA-CAM and the HBA16 would wire up according to the instructions, which I'll send to you in a separate email.