Cool web site and a LED issue.

I've looked at some brake threads for master cylinder info and figured I would throw this out there too.


The car had good brakes with this build.
No complaints except for the nuisance warning light.
This is a B body with manual brakes.
But I'm curious why it is doing this.
Checked one of my A bodies with the same brake system (valve,etc) and it was "out of limits" with the Fluke after being driven hot.

(The A body is still using a
Raybestos MC36412 master cylinder)
So I'm thinking a drop in resistance I'm seeing in my B body valve/switch isn't normal.

I have installed a new A body valve (not rebuilt) from Inlinetube just to see what happens.
I'm using a Diplomat master cylinder on the B body with the 2 bolt adapter.
It has a 1.031 bore.
Again, bolted right in with the adapter and the brakes worked fine.
Stock rod was good.
This master cylinder is aluminum and was new when installed 5 years ago.
(Problem here?)
It has the same fitting sizes as the A bodies original master cylinder.
9/16 20 and 1/2 20.
(Don't want to make new lines./fittings . I did that once already)
Front calipers are Diplomat.
The rear drum cylinder are 15/16.. 10 inch drums.
(WCA 78734)
Need to bleed them and recheck but I'm thinking it will be the same result.
Something will move and "make" the switch enough to cause the LED warning light to come on.
Seems to come on about 5.7 K resistance.

These are just links to the master cylinder I'm using on the B body.
https://www.autozone.com/brakes-and...ster-cylinder-brake-system/49330_101749_2558#

https://www.oreillyauto.com/detail/...0/1988/dodge/diplomat?q=master+cylinder&pos=1

Brake Master Cylinder-First Stop Dorman M99294 82702402375 | eBay

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