2003 XLT 2WD - master cylinder replacement

[TheOldBear]

The brakes went soft and inconsistent, without any leaks - so its time to replace the master cylinder.
Ordered a replacement [Raybestos] fro RockAuto and it looks like a good match for the original.
On the top of the cylinder there is a switch or sensor screwed into a port toward the end [in line with the reservoir ] - I did not see this on the many YT videos concerning Ranger master cylinder replacement [mostly a few years older, or 4x4 versions]. The parts.ford.com web site is unhelpful, showing no 'related parts' or listing possible switches/sensors for the cylinder port.
Since this is brake related, I am concerned about ensuring a leakproof fit transplanting the switch to the new cylinder. [I would prefer to just use a new part]

Has anyone done the replacement recently? Were you able to reuse the switch? If not, what is the switch called so a replacement can be ordered?

 

[franklin2]

If the port would leak brake fluid when the pedal was pushed, it's most likely the interlock switch for the cruise control. To knock out the cruise control when the brake is applied. They have one on the brake pedal switch, but I think this is a redundant switch, Ford must have gotten paranoid about the cruise sticking on.

If that is what the switch is for, then it might be one of the famous switches that catch the vehicle on fire, and that they had a big recall on. Don't know, maybe it's for something else. What colors are the wires going to it?

 

[TheOldBear]

The wires going in to it are yellow and green, in a large rectangular connector. Looking on parts.ford.com it did seem to be the cruise control 'cutoff' switch - and provided a part number. I ordered the Motorcraft part from Amazon on Friday, and it was delivered today. It's going back as the new part's connector is smaller and oval. I decided to clean and reuse the old part, will keep an eye on it for leaks.
Speaking of leaks, the old master cylinder was leaking internally and also dribbling inside the mounting flange to the booster. The brake line routing got in the way of a socket & extension, is I decided to do the 'bench bleed' in the vehicle with the brake pedal. After the bench bleed & reconnecting the lines to the ABS unit the wheel cylinder bleed went as expected - one oddity was the rear wheels used a 10mm wrench, while the front calipers used 3/8 inch - just different enough to be annoying.

 

[TheOldBear]

Here's a picture of the old [brick color] and new [black] switches - the new one is going back for a refund

 

[franklin2]

Rear wheel cylinders may have been replaced at some previous time. China doesn't care what size wrench the bleeder takes when they make them it seems.