Posts: 7
Threads: 3
Joined: Dec 2011
happy new year everyone
i've been working on a 73 mach 1 and have encountered a couple of problems. hopefully someone can help out. after installing a new master cylinder/ booster combination and bleeding the breaks i have no pedal. i replaced the master cylinder but that did not help. i'm told that there is an adjustment on the rod out of the booster. any tips on how to adjust the rod. also, when i first started the rebuilt engine and ran it thru its break in time the tach worked just fine. now all of a sudden it does not work. any tips on how or where to check to see whats wrong.
thanks,
paul
Posts: 3,119
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Joined: Jan 2010
Hey Paul, you didn't mention if it felt like anything was happening or not, when you pushed the brake pedal? So we'll start there 1 check for mechanical movement. Take the master cylinder off the front of the booster. Do not disconnect the lines! have some one push the brake pedal and watch the rod thru the booster and see if it moves, it should move roughly 1 to 1 1/2" If it moves in and out make sure you push it all the way back in, pedal should be all the way at top. Measure the amount of rod sticking out of the booster it should be roughly the same distance. As it is to the center of the puck in the back of the master cylinder. If that is correct. reassemble everything and have a friend push the pedal as you watch the holes in the master cylinder you should be able to see the plunger/spring assemblies moving. If all of this works. Did you bleed the master cylinder itself? They won't work if not bled. If you still have problems let us know and we'll see if we can think of something else. 2 the tach wire should be attached to the negative side of the coil, did it come loose or break off? trace it back to the dash and make sure it has continunity, If the wire is good maybe the tach itself gave up? Let us Know JTS 71 Mach1
Posts: 7
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Joined: Dec 2011
hi jts71
i think i solved the break problem. adjsuted the rod out and now i have a high break pedal. as for the tach, there was only one wire coming out of the loom to the coil. it is attached to the positive side of the coil for ignition. i never saw another wire. i've had a couple of guys helping me and they changed the carb and since then the tach has not worked. looking at the wiring schematic it doesn't show a seperate wire for the tach. it appears that somewhere in the wiring loom the tach wire is connected to the ignition wire and that in turn connects to the coil. i'm almost positive that when i first hooked everything up to break in the engine that that is the way i hooked up the wires. there never was a wire going to the negative side of the coil. unless i had them backwards at the time of start up and didn't catch it. look forward to any help.
thanks,
paul
Posts: 58
Threads: 2
Joined: Jul 2011
The tach is what is known as a "two wire" tach. The wire for the positive side of the coil goes through the tach. Depending on what part of the tach fails, the tach will either not function or the engine will not start. I had mine converted to a three wire tach by Rocketman's,
http://www.rccinnovations.com/ and have been satisfied with it so far. The face is factory, you add two wires (one to ground, the other to the neg side of the coil) and it's cheaper than having the factory tach rebuilt to original.
Steve
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Joined: Jan 2010
(01-03-2012, 10:05 AM)rvrtrash Wrote: The tach is what is known as a "two wire" tach. The wire for the positive side of the coil goes through the tach. Depending on what part of the tach fails, the tach will either not function or the engine will not start. I had mine converted to a three wire tach by Rocketman's, http://www.rccinnovations.com/ and have been satisfied with it so far. The face is factory, you add two wires (one to ground, the other to the neg side of the coil) and it's cheaper than having the factory tach rebuilt to original.
Steve
Good Job
on the tach, I was not aware of how the factory tach is wired? Most tach's have a wire hooked to the negative/point side of the coil, to count the pulses every time the points open. Thus telling the tach what speed the engine was turning. I wonder how Ford did it since back then they didn't have crank sensors or anything like that. All they had were the points???????? kinda makes you go HHMMM? JTS 71 Mach1
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