[A/S] The hard way to learn about electric brakes, volume 1

["nickcrowhurst" <NickandSandra@xxxxxxxxxxx>]

Hello from a new Airstreamer, Nick Crowhurst. My wife and I are from 
England, but we spend part of the winters in the wonderful USA to be 
with our son and his family. On our first visit we saw a beautiful 
silver apparition travelling on I95. "What", I said out loud, "is 
that beautiful beast?". We had never before seen an Airstream. It 
was love at first sight. To those who appreciate Pirsig's "Zen and 
the art of motorcycle maintenance", no explanation is necessary. 
Quality, just quality. We did our research, saved our pennies, and 
now own a beautiful 1988 Excella 25 ft and a Dodge Cummins 250 long 
bed quad cab. We have spent the last two vacations bringing the 
trailer up to standard, and the purpose of this posting is to 
describe our adventures with electric brakes, in the hopes that some 
other newbies might benefit from our experiences. The electric 
brakes did not function at all, and the following steps were 
necessary to correct that:-
1. We realized we had to work from the front of the rig, back 
towards the brakes.The new electric controller was found to be 
defective, and no current was arriving at the 9 way socket at the 
rear of the pick-up. The controller was exchanged under warranty, 
but I had to buy another new one while the orignal was travelling in 
the mail. We only had a limited vacation. Our local Airstream dealer 
had a test machine to show that the second new controller delivered 
the correct amps at the correct voltage. Very useful, as my digital 
multimeter can't handle the high amps.
2. There was still no sign of life from the brakes, so the next 
check was the 9 way connector on the trailer hitch. We dismantled 
the socket, and found that the blue brake wire had detached from its 
screw connector, and was shorting across to the white ground, with 
obvious scorch marks. This was corrected, and optimism reigned in 
the camp when buzzing sounds could be heard from the brakes.
3. However, the buzzing would not stop, and the brakes were locked 
on. We read the manual, and realized that the breakaway switch must 
be operating, even though we had fitted a new switch as part of the 
renovation. The red wire to the switch is the live feed from the 
battery, and the blue is the return to the brakes. These two wires 
take their own lonely route back to the brakes via the inside of the 
main chassis members. When we waggled the two wires, the brakes 
unlocked. If we waggled them again, the brakes came on. We thus had 
a short between the two wires in a totally inaccessible place, and 
the wires would not pull through. We had to replace the wires by a 
new route. We removed the interior lounge completely, drilled out 
the rivets on the internal panelling to the left of the 12 volt 
distribution panel, and after several hours work, found the ends of 
the breakaway wires. We cut these, connected new wires, and routed 
these alongside the main 9 way harness. This involved using a stiff 
wire to thread through the double floor. 5 hours later, the interior 
was restored, and the brakes responded properly to the controller, 
and morale was high in the camp!
4. BUT. The brakes locked on, and would not release, even though the 
ammeter showed no current to the magnets, the tow vehicle was 
disconnected and the batteery kill switch was off. This was clearly 
mechanical. We had earlier fitted new brake shoes and magnets and 
wheel bearings as part of our restoration. The next bit was the 
nightmare, and readers of delicate disposition should skip this bit! 
I spent FOUR DAYS repeatedly stripping and re-building the wheels. I 
made 4 visits (320 miles) to the Airstream dealer (Sanders at 
Alachua, FL) who had supplied the parts, including taking a complete 
backplate assembly to the mechanics. The problem was obvious. The 
actuating arm would jam against the metal brake shoe when attempting 
to release. The rub marks were visible. I tried everything I could 
think of. Lithium grease, adjusting tighter and looser. I was 
stumped, the dealer was stumped. In despair, I purchased 4 complete 
back plate and brake assemblies, fitted them, and now the brakes 
work!! Total spend about $600 dollars plus travelling, plus labour, 
and a vacation spent lying in a field full of fire-ants. I e-mailed 
Dexter to find out if there was any explanation. There reply was:

 "Dexter's 10 x 1-1/2" electric brakes went through a design change 
right around 1988. It is likely that your 1988 model trailer was 
built originally with the older style. The magnets and magnet 
actuating lever arms are different and our kit catalog does a poor 
job of explaining it well. The older style brake would have used K71-
057-00 magnets and K71-325-00 and K71-326-000 lever arms. The newer 
style brakes use K71-177-00 magnets with the K71-327-00 and K72-328-
00 lever arms. 

Since you have completely replaced the complete brake assemblies you 
have already solved your problem."

I have written to the Airstream dealer to show this reply, in the 
hope that this can be avoided in the future. We now have a trailer 
with working electric brakes, and after 2 years, we intend to hit 
the road for a one mile test run. Wish us luck! Many thanks, Hunter, 
for all your work on this excellent list. From Nick Crowhurst.