Greetings,

Its been two years of mowing yards and saving money but the boy who is 15 is ready for the upgrades to his '72 long bed.
The day he bought it!

The Boy by 59'er F100 posted Aug 6, 2020 at 2:33 PM

Here is where I'm at:
-original drums 4 corners
-found donor '73 and pulled i-beams and arms,
-pulled '73 MC with booster and linkage to attached to pedal,
-pulled brake line orifice fittings going into '73 MC
-'73 tie rod was bent due to how the forklift lifted the front end (salvage yard guy, not me) --> looks like and measurements show '72 tie rod will fit '73 spindles no problem

Installed new '73 king pins (same size as '72), rotor (bearings) and calipers/pads, new '73 MC with Booster

Re20200802_154055 by 59'er F100 posted Aug 6, 2020 at 2:33 PM

MY QUESTION: I intend to use the original '72 Brake Pressure Differential Valve and plumb into new '73 MC...will I need to use the fixed orifice fittings from the OLD '73 MC on the NEW '73 MC? If the larger pot of the MC is for front disc, the OLD '73 MC actually had the smaller orifice on the big pot. Does this make sense? I placed the NEW '73 MC fitting next to the old one for reference see image.
Which pot should use the smaller orifice fitting?

I intend to run an aftermarket proportioning valve for the rear drums.

Re20200805_193953 by 59'er F100 posted Aug 6, 2020 at 2:33 PM

Seeing the different orifice sizes has me curious as well as the thread sizes of the fittings are opposite of the OLD '73 and NEW '73 MC (in opposite spots)

Re20200805_194049 by 59'er F100 posted Aug 6, 2020 at 2:33 PM

new '73 MC is Raybestos MC36399 part number.

Re20200805_194120 by 59'er F100 posted Aug 6, 2020 at 2:33 PM

Lastly the brake pedal attached to the NEW '73 MC is now 2" lower (closer) to fire wall...I assume this is due to less travel required for booster and I intend to fab new bracket for switch...Does this sound normal?

Re5_194212 by 59'er F100 posted Aug 6, 2020 at 2:33 PM

If you are still with me, I appreciate your input on this as I'm working to make this safe as possible for my child and brakes tend to be important for stopping!