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ndfrigi |
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#4921
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Advanced Member ![]() ![]() ![]() ![]() Group: Members Posts: 2,965 Joined: 21-August 11 From: Orange County Member No.: 13,474 Region Association: Southern California ![]() ![]() |
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Cairo94507 |
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#4922
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Michael ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 10,300 Joined: 1-November 08 From: Auburn, CA Member No.: 9,712 Region Association: Northern California ![]() ![]() |
I have been eagerly awaiting updates. But a grandkid comes first. (IMG:style_emoticons/default/beerchug.gif)
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bkrantz |
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#4923
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914 Guru ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 8,345 Joined: 3-August 19 From: SW Colorado Member No.: 23,343 Region Association: Rocky Mountains ![]() ![]() |
Sorry for the wait, guys. Getting my wife away from the new grand baby was tough. Then I found out she committed us to return. In July. In Tucson. Yikes!
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bkrantz |
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#4924
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914 Guru ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 8,345 Joined: 3-August 19 From: SW Colorado Member No.: 23,343 Region Association: Rocky Mountains ![]() ![]() |
OK, back to work. After confirming that the new MC pressure warning switch works, I decided to install it.
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bkrantz |
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#4925
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914 Guru ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 8,345 Joined: 3-August 19 From: SW Colorado Member No.: 23,343 Region Association: Rocky Mountains ![]() ![]() |
Here's the new MC with the original i.e. 50 year old switch installed.
I did find out that when I removed the old switch, the MC does not leak fluid. Maybe I will not have to bleed the system again! (IMG:style_emoticons/default/cheer.gif) Attached thumbnail(s) ![]() |
bkrantz |
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#4926
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914 Guru ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 8,345 Joined: 3-August 19 From: SW Colorado Member No.: 23,343 Region Association: Rocky Mountains ![]() ![]() |
So I swapped the new switch in, after confirming again with my multi-meter that it works. But when I connected the leads and turned on the ignition, the damned warning light was still flashing. ARRRGGGHHH. (IMG:style_emoticons/default/headbang.gif)
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bkrantz |
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#4927
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914 Guru ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 8,345 Joined: 3-August 19 From: SW Colorado Member No.: 23,343 Region Association: Rocky Mountains ![]() ![]() |
After falling around with the 3 switches (original two connection, new two connection, and new single connection) I decided to get out the original MC and learn more.
I unscrewed the cap for the warning system bore, and pulled out the piston. Attached thumbnail(s) ![]() |
bkrantz |
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#4928
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914 Guru ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 8,345 Joined: 3-August 19 From: SW Colorado Member No.: 23,343 Region Association: Rocky Mountains ![]() ![]() |
As I understand the function, as long as pressure for the front and rear circuits is equal, the piston remains centered, and the plunger on the switch can be fully extended, poking into the smallest diameter segment on the piston (with some red marker). If the pressure is unequal, e.g. if the front or rear circuit loses fluid, the piston shifts and forces the plunger into the switch, making the connection.
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bkrantz |
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#4929
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914 Guru ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 8,345 Joined: 3-August 19 From: SW Colorado Member No.: 23,343 Region Association: Rocky Mountains ![]() ![]() |
With the piston back in the old MC, I installed the new switch and it works.
Back on the car, I confirmed that both front and rear brakes work. But as best as I can tell, the warning piston is not centered, so as soon as I screw the new switch in, it pushes in the plunger and turns on the light. More figuring to do. |
Puebloswatcop |
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#4930
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Senior Member ![]() ![]() ![]() Group: Members Posts: 1,443 Joined: 27-December 14 From: Mineola, Texas Member No.: 18,258 Region Association: Southwest Region ![]() |
whew,
Glad you're back. I was turning a very dark shade of blue from holding my breath with anticipation. Welcome home and congrats again on the new grand baby.... |
bkrantz |
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#4931
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914 Guru ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 8,345 Joined: 3-August 19 From: SW Colorado Member No.: 23,343 Region Association: Rocky Mountains ![]() ![]() |
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bkrantz |
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#4932
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914 Guru ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 8,345 Joined: 3-August 19 From: SW Colorado Member No.: 23,343 Region Association: Rocky Mountains ![]() ![]() |
I tried again to get the brake MC warning system to reset.
I used a thin, sharp probe to see if I could manually shift the warning piston--no luck. I opened first a front, and then a rear caliper bleeder, and stomped on the brake pedal--no luck. Running out of options before I have to replace the (new) MC. |
bkrantz |
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#4933
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914 Guru ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 8,345 Joined: 3-August 19 From: SW Colorado Member No.: 23,343 Region Association: Rocky Mountains ![]() ![]() |
OK, time to dig deeper into the MC (without removing it). First, remove brake fluid from the reservoir.
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bkrantz |
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#4934
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914 Guru ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 8,345 Joined: 3-August 19 From: SW Colorado Member No.: 23,343 Region Association: Rocky Mountains ![]() ![]() |
Next, remove the cap that covers the secondary bore for the pressure warning piston.
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bkrantz |
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#4935
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914 Guru ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 8,345 Joined: 3-August 19 From: SW Colorado Member No.: 23,343 Region Association: Rocky Mountains ![]() ![]() |
Next, remove the warning piston. Note this shows the piston with its end cap removed. But the piston hits the front suspension cross member.
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bkrantz |
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#4936
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914 Guru ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 8,345 Joined: 3-August 19 From: SW Colorado Member No.: 23,343 Region Association: Rocky Mountains ![]() ![]() |
I loosed the MC retaining nuts enough to tilt it down so the piston cleared the cross bar.
Here is (from left to right): cylinder end cap tiny retaining C-clip forward spring perch rear spring perch warning piston Notice something missing? Attached thumbnail(s) ![]() |
bkrantz |
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#4937
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914 Guru ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 8,345 Joined: 3-August 19 From: SW Colorado Member No.: 23,343 Region Association: Rocky Mountains ![]() ![]() |
Here's the piston from my old MC (top) compared to the new one, which is missing the spring. Probably not a good thing.
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bkrantz |
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#4938
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914 Guru ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 8,345 Joined: 3-August 19 From: SW Colorado Member No.: 23,343 Region Association: Rocky Mountains ![]() ![]() |
Comparing old and new MC.
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bkrantz |
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#4939
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914 Guru ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 8,345 Joined: 3-August 19 From: SW Colorado Member No.: 23,343 Region Association: Rocky Mountains ![]() ![]() |
Measuring the depth of the warning switch location, from the mounting face on the outside to the bore wall inside.
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bkrantz |
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#4940
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914 Guru ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 8,345 Joined: 3-August 19 From: SW Colorado Member No.: 23,343 Region Association: Rocky Mountains ![]() ![]() |
On the old MC it measures about 1.04"
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