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brake light switch location?
Posted: Sun Jan 09, 2011 12:04 pm
by powerwagontim
Hi Guys,
Making good progress assembling the myriad brackets, castings etc on my frame. Actually got it sitting on tires now instead of jackstands. A couple of questions have come up. First, when I bought the 4 rubber brake lines, it turns out they are all the same. Anyone have the length of the rear line (the longer one)?
Second, I am used to seeing the brake light switch on the tail of the master cylinder. My Greek wiring harness will only reach as far as the big brass coupling block that passes through the frame. The coupling block has a port with 1/8" pipe threads, with a pipe plug. Were any M37s outfitted with the brake light switch mounted on the brass block? I have assembled it this way and cant see any problems (Power Wagons are set up this way).
Primed about 50 more parts this morning, they will get color tomorrow and then another big burst of progress!
Thanks,
Tim
Re: brake light switch location?
Posted: Sun Jan 09, 2011 12:57 pm
by SOTVEN
I DON'T KNOW THE LENGTH OF THE REAR BRAKE LINE, BUT THERE IS A NOS ON EBAY RIGHT NOW. AS FOR THE MC BRAKE LIGHT SWITCH, MY GREEK M37 HAS IT MOUNTED AT THE REAR OF THE MC, ON TOP OF THE OUTPUT. AND THAT IS THE ONLY WAY I HAVE SEEN THEM IN GREECE. DID YOU ROUTE THE HARNES PROPERLY? IS THERE A CHANCE YOU MIGHT HAVE MADE AN UNECESSARY "LOOP" SOMEWHERE?

Re: brake light switch location?
Posted: Sun Jan 09, 2011 1:13 pm
by powerwagontim
Hi Sotven,
I have a bid on the ebay hose already!
Interesting info on the location of the Greek switches. Pretty sure I have the harness in the right place, going by the locations of all the clamps shown in the manuals. There are 3 clamps across the transfer case crossmember that the wire for the brake switch goes, its pretty direct. I debated lengthening the harness but opted for moving the switch.
Thanks,
Tim
Re: brake light switch location?
Posted: Sun Jan 09, 2011 4:54 pm
by MSeriesRebuild
The stop light switch being mounted in the brass block is fine, all later model trucks have it there. As far as functionality, it doesn't matter where in the pressure circuit that it's mounted, the result will be all the same.
Re: brake light switch location?
Posted: Sun Jan 09, 2011 5:53 pm
by powerwagontim
Thanks Charles,
So to clarify, did the B1 trucks have it on the brass block?
I figured it would work fine, as that is how the Power Wagons were set up. Basically anywhere in a pressure line would work.
Tim
Re: brake light switch location?
Posted: Sun Jan 09, 2011 6:10 pm
by MSeriesRebuild
powerwagontim wrote:Thanks Charles,
So to clarify, did the B1 trucks have it on the brass block?
I figured it would work fine, as that is how the Power Wagons were set up. Basically anywhere in a pressure line would work.
Tim
Yes that is typical on B1 trucks, that is where you see it on most, of course when they get into civilian hands; no telling what you might see. Many M/C's don't have the 1/8" NPT port anymore eliminating that mounting point.
Re: brake light switch location?
Posted: Sun Jan 09, 2011 7:00 pm
by powerwagontim
Hi Charles,
Thanks again. One last question, and its purely academic as it is all done, but would the switch mount to the top of the block or the bottom? It didnt seem to be enough room to mount to the top, with the fuel line and vent line running above, so I rotated the block 180 and mounted the switch to the bottom. Just enough room for the Douglas connector and not pinch the wires. The hole through the frame is actually offset 1/4 towards the top, giving more room below.
Tim
Re: brake light switch location?
Posted: Sun Jan 09, 2011 9:08 pm
by MSeriesRebuild
powerwagontim wrote:Hi Charles,
Thanks again. One last question, and its purely academic as it is all done, but would the switch mount to the top of the block or the bottom? It didnt seem to be enough room to mount to the top, with the fuel line and vent line running above, so I rotated the block 180 and mounted the switch to the bottom. Just enough room for the Douglas connector and not pinch the wires. The hole through the frame is actually offset 1/4 towards the top, giving more room below.
Tim
Makes no difference at all.