Another Vacuum / Hydraulic question

[Idaho Ken]

Hello all. I recently acquired a 77 27-footer with the vacuum/hydraulic disc break system. All appears to be in good shape and I would like to maintain the original system. My intended tow vehicle is a 96 Ford F-350. I have the trailer manuals with all the good information about how to set up the tow vehicle, AS part numbers, etc., but have trouble finding suppliers. Question #1: Will a heavy-duty "T" style pneumatic coupler work for the tow vehicle vacuum line connection or is there another recommended connector? I cannot seem to find anyone who can supply the original connector. Question #2: Can someone recommend an appropriate brake controller for the tow vehicle that will work correctly with the electric proportioning valve on the "Hyro/vac"? Question #3: Can anyone recommend a part number, vendor/source for the inline check valve for the vacuum line on the tow vehicle? I have the orginal Midland Ross part numbers but all local RV and brake system specialists look at me with glazed over eyes! That's probably enough questions for now. Thanks in advance for any assistance. Ken in Idaho

[dwightdi]

I had a '77 31 footer hooked up to a Ford 350E van. It was already attached when I purchased it so I did not do the work. It used a proportional control directly connected to the brake line which was teed in from the engine compartment. It used a quick disconnect connector at the back of the TV. The vac line was tied in a line on the top of the manifold and used a thick vac line all the way to the back. I no longer use this van and the disk brakes because the clevis pins broke loose on the caliper carriers and the caliper carriers developed fatique cracks at other locations. I did use the same controller after I switched to electrics. Two years after that, I switched to the dually truck.

[Idaho Ken]

Thanks Dwightdi for the reply. It looks like a pretty straight forward installation and the system is easy to understand, if I could only find the check valve and a connector that would work. I am concerned about using a conventional air connector. I am wondering if since it is designed for pressure, a vacuum application may allow leaks. I guess I will just have to do some experimenting. The check valve is really being elusive and hard to find. I am told by local "brake guys" that a good high quality, off the shelf controller should work but I wanted to hear from someone who REALLY knows. The local brake guys have never seen a system like this so I question thier advice!

[Inland RV Center, In]

Originally Posted by Idaho Ken

Hello all. I recently acquired a 77 27-footer with the vacuum/hydraulic disc break system. All appears to be in good shape and I would like to maintain the original system. My intended tow vehicle is a 96 Ford F-350. I have the trailer manuals with all the good information about how to set up the tow vehicle, AS part numbers, etc., but have trouble finding suppliers. Question #1: Will a heavy-duty "T" style pneumatic coupler work for the tow vehicle vacuum line connection or is there another recommended connector? I cannot seem to find anyone who can supply the original connector. Question #2: Can someone recommend an appropriate brake controller for the tow vehicle that will work correctly with the electric proportioning valve on the "Hyro/vac"? Question #3: Can anyone recommend a part number, vendor/source for the inline check valve for the vacuum line on the tow vehicle? I have the orginal Midland Ross part numbers but all local RV and brake system specialists look at me with glazed over eyes! That's probably enough questions for now. Thanks in advance for any assistance. Ken in Idaho

Inland RV Center, has all the remaining repair parts for the original Airstream "disc brake" system.

You can use a 3/8 inch "quick disconnect" air line fitting for the vacuum lines.

There are two controllers available that offer good to superior braking results.
They are both made by Hayes.

One is a standard model, and the other is the Genisus model, which we have provided for that brake sysytem for some time, with very good results.

We also have the check valves.

Depending on the overall condition of your disc brakes system, such as "is the sync valve ok," you may wish to upgrade the system with a new style actuator, that does reguire some additional wiring, but is not difficuolt to do, but more importantly, does not require a "vacuum" supply.

Andy