1972 f100 disc brake setup help

[Elliott74]

1972 f100 power disc brake setup from a dent side. No factory proportioning valve from the master. It has a aftermarket brass distribution block for the front disc brakes and a fully adjustable proportioning valve that the rear drum brakes run through. Is this a safe set up? On another forum someone said if it dose not have the factory proportioning valve and you crash you can get manslaughter charges. From the factory did the trucks have full pressure to the front disc brakes with a proportioning valve to the rear? I do better with engines not supper strong with brakes just trying to learn ?

Thanks

[sargentrs]

Ultraranger and HIO Silver are the resident experts, IMHO, when it comes to this kind of swap information. You can search for their threads in this section. Here's an sample of the knowledge available http://fordification.com/forum/viewtopic.php?t=75384 As for me, I'll be going with a closer to factory application using a style like came in the dent side generation. https://www.carolinaclassictrucks.com/F ... valve.html or Mustang/Cougar application http://www2.cougarpartscatalog.com/stor ... -Ford.html As for the whole "crash/manslaughter" thing, IDK. Your best defense is safe driving. Leave plenty of room between you and other vehicles, stay at or below the posted speed limit, and maintain an acute awareness of the traffic and road conditions around you. However, the closer you stay to a factory application used by thousands of other hobbyists, like the above, and stay away from setups that require "judgement" adjustments from someone not an expert in brake systems, the better off you'll be in a legal situation.

[sargentrs]

Sorry. Double post.

[colnago]

My two cents.

I did a drum-to-disc conversion on my '67 F250. I'm using a '67 booster with '68 MC, calipers, etc. I am also using one of those brass proportioning valves (I pulled a Ford prop valve from a truck in the junk yard, but the shuttle inside didn't move, so I junked it). I do not have an adjustable prop valve for the rear. Sounds like you might have a drum-drum prop valve, and the PO was trying to get it working for disc-drums (speculation on my part). When set up correctly, the prop valve is supposed to let the rear drum brakes start first, then let the front discs start to engage. That way, you don't get everything going to the front.

If you're worried about liability, sell it. Sorry, don't mean to sound harsh, but it's 45 years old. Drive it, enjoy it, mod it, love it, or get rid of it. I'm an old guy, so I drive like an old man. I have insurance that covers me hurting anyone, but don't have comprehensive/collision, so if someone T-bones me, I'm SOL (S### Out of Luck). I don't tailgate, or drive fast, so it's highly unlikely (though still possible) that I will kill anyone.

If it were my truck, I would find out about the prop valve(s), and go from there. If you're in SoCal, come on over. I'll do your brakes if you do my engine!

Again, just my

Joseph

[Elliott74]

Yea I'm not to worried about it.The brakes work well and better then the original drums in the front I'm sure. Just wanted to see what others had to say about it. I think I will put a stock distribution block on before I sell it just to be on the safe side. What engine work do you need done ? I just did the engine in my dent it came out nice.

[colnago]

Looking good! I am so jealous!

I'm finishing a rebuild on a 352. I thought it was all torque specs and assembly lube. Now that the end is in sight, I'm reading all of these posts on the break-in process, and how the first 30 minutes becomes a make-or-break situation for the cam lobes. So, either I will have the most awesome 352 to ever hit the streets , or I have to tear it down and replace the cam If the second one happens, after I stop crying, I might become a monk and devote my life to rescuing injured pigeons.

I really wouldn't worry about the liability of using dent parts in a bump. I have a C6 in my '67, which was not even an option at that time. Long story short, it popped out of Park, coasted across the parking lot, and hit a car. I told the police and the insurance company that it was a mechanical failure. Neither cared beyond that point.

Joseph

[Elliott74]

Aw I would not worry too much about it .Did you use PLASTIGAUGE for clearance on the low end ? Is it a stock cam ? Did you check for bind on the springs if its aftermarket. I know the 352 did not use ajustable valve set up unless it was from like 1958-1960. All this information can make a person crazy from the internet .... like me and my brake question. If its a stock rebuild or mostly stock just make sure to get some zinc additive or a oil with zinc additive,triple check to make sure once she fires you don't have to shut her down and run her for 15-20 min above 2000 rpm and just change the rpms every couple of min and you should be fine. I had a 352 in my 1966 f100 loved that truck but sold it when I moved from NorCal to SoCal. Let me know how it goes

[ultraranger]

None of the Bumpside F100s came from the factory with front discs. All Bumpside F100s came standard with manual 4-wheel drums. Power brakes was optional on Bumpside F100s with all-wheel drums.

Factory fronts discs weren't available on the Bumpsides until 1968 but that was only optional on F250s and F350s. Power brakes was also optional on them.

All wheel drum brake F100s through F350s didn't come with proportioning valves and neither did the '68-'72 F250/F350 trucks with factory front disc brakes. They all used a pressure differential valve. In the case of optional front discs, there was a stand-alone metering valve plumbed inline to the front discs circuit, in tandem to the PDV.

In '73, front (manual) disc brakes became standard equipment on all F100 - F350 trucks. In '73, three functions were integrated into one brake valve body assembly: Metering to the front discs, Pressure differential sensing between the front and rear brake circuits and for the first time, Proportioning was used to control the rear drum brake circuit.

A manually-adjustable proportioning valve could be installed as a stand-alone item, plumbed into the rear brakes. The main problem is, very few people have the pressure gauges to adjust the setpoint of the manually-adjustable proportioning valve so that it's at the correct 'knee-point' of controlling the pressure curve to the rear brakes, proportional to the amount of pressure being applied to the front brakes.

Many companies sell M-A proportioning valves but, in the fine print on all of them it will say that it's for "off road use only" and/or "not DOT approved."