2001 F-150. I've got a leak around the warning switch and can't seem to find info about replacement. Is the switch and switch retainer screwed into the reservoir or is the outer ring screwed into reservoir and more of a compression type fitting that holds switch in place? Also, after removing and repairing will bleeding be necessary? Looks like everything I'm taking apart is above fluid level after I siphon enough fluid from reservoir to replace fitting. Thanks, Tom

 

My 1997 FSM says the level switch is not replaceable, replace the master cylinder.

However, the level switch and internal float is actually part of the reservoir, and O'Reilly has the reservoir available (at least near me) in 24 hours for my 1997 (2 reservoir types, 1 with, 1 without Cruise Control) for $29.99.
They show 2001 reservoirs (3 types, with, without, and rear disc brakes for $29.99 - $32.99), 24 hour availability.
All come with a new rubber grommets to fit on the old master. Lube new grommets with clean DOT-3 brake fluid.

I'm assuming that you really don't want to get into bleeding, nor replacing the whole master cylinder.
Working very carefully, it may be possible to lower fluid level, then pry off the old reservoir, install reservoir with new grommets, refill, without getting air into the aluminum master body.

May want to scope that out first, as the master is mounted at an angle with its front up, it would seem that putting the truck on a down-hill, or putting rear axle on jackstands, to get the master's two reservoir ports level, would help a great deal. Otherwise, I would think fluid would spill out of the front-most one, which would mean bleeding the whole system then.

Many years ago, I replaced a Ford master with the plastic reservoir on a Panther-chassis (full-size RWD) car. The only master I could get that weekend was without reservoir, so I had to reuse the old reservoir. I tried separating the reservoir from the master on the bench... no go! That sucker was in there tight, and I needed to save the reservoir. I had to mount the master back onto the booster to hold it good, and then use two wide flat screwdrivers as pry bars between reservoir and master. I think I used a scrap maybe 1/8" thick hardboard to protect the reservoir plastic from the screwdriver shafts, helped spread the force across the plastic.

The old reservoir with new lubed-up grommets went on with some good hand force, with a slight rocking motion.
I don't remember if I put the grommets into the master FIRST, or onto the Reservoir bottom FIRST. I DO remember that one way it just did NOT want to go on, switched to the other way, it went on OK. Seems there was one way to do it... but I don't remember which! The reservoir kit may have instructions that say which way.

 

Thanks Torky-I'll see what can be done but looks like new master cylinder is probably in my future! Tom