2001 expedition MC

[WiscoF100]

My research isn’t fairing well identifying the front and rear circuits and specifically what this little bastard does nearest the booster. I’m finding this vs that answers. Which port/piston is front and is that little valve body a residual pressure device or proportioning valve for drum brakes? Internet can’t agree.

OE application is 2001 Expedition installed in my 78 F-150. Disc front drum rear. No valving etc. Direct front/rear plumbing. My front calipers are holding pressure. Just smoked them on a test drive. 450*. When parked the calipers etc are making angry noises but I can’t tell if it’s them relaxing/bleeding off pressure or building pressure.

Pictured below is how I plumbed the truck according to old school MC plumbing or at least how I use to understand it. Could the valve be gutted? If the circuits are reversed, will it function correctly unaltered for the drums?

Thinking about not fucking with this much and just get on with installing the rear discs.

 

[Gumbybronco]

I found this image of an 2001 F150 MC and they share most parts with the Expeditions

Here’s the source

Mystery fitting on 2001 F150 V6 brake master cylinder - Ford Truck Enthusiasts Forums

1997 - 2003 F150 - Mystery fitting on 2001 F150 V6 brake master cylinder - Doing some work on brakes & found something I can't identify. Went to junk yard & checked out another 2001 F150 V6, with the same item (just less rust) It's threaded into the rear socket on the right side of the brake...

www.ford-trucks.com

Looks like the front port is front brakes.

FYI the sensor is for cruise control and was an option.

 

[rattle_snake]

given the extra fitting, the back port is the rear circuit. It may or may not do anything, depending on antilock system. If 4 wheel antilock the fitting is just a spacer.

Assuming the 01 ex was disc/drum, the circuit with bigger swept volume is the front (disc) circuit. You can tell easily from the F150 MC image that the front part is the disc as the distance between the inlet (from reservoir) to the output is longer.

The original MC on my truck was opposite from the late model one I installed. There is no convention.

 

[WiscoF100]

Thanks guys. You confirmed my suspicions. And interesting note about the rezzi and output locations and relative distance.

I couldn’t tell ya what the donor was brake wise or cruise etc. in fact I dumped the core in exchange for the MC pictured. The fitting/valve is OE and most certainly operational. Not gutted/straight through.

So, I’ll swap the line orientation. 👍

Will the check valve cause issues going directly to the rear drums? Will they drag? Should I gut it?

 

[rattle_snake]

 

[WiscoF100]

Yeah yeah your artistry if fantastic

I understood the distance before the rocket ship

 

[gt1guy]

This is a great post. Using swept volume to determine which port goes where is the way to go. That's the number you need, even if you don't know the exact numbers you can tell which one would be the bigger of the two.

 

[rattle_snake]

Thanks. Trying to keep with the IBB theme... haha