Here's all the info that I'm aware of the the systems that are involved, truck is originally a 62 F100 and that is the master cylinder used, the front disk and rear drum brakes are out of a 76 f150. The hydroboost is out of a 93 c3500 HD and the clutch slave cylinder is 1" bore which matches the installed 62 F100. The installed master cylinder and hydroboost have a 1 in stroke while the clutch slave cylinder has a 1.5 in stroke for safety. The brake pedal ratio is 6:1

1" 62 f100 master cylinder piston bore 0.785"

1" 76 f150 master cylinder piston bore 0.785"

1" clutch slave cylinder bore 0.785"

1.25" 93 c3500 HD master cylinder piston bore 1.227"

1.0625" 62 F100 front piston diameter 0.887"

2.88" 76 f150 front caliper piston diameter 6.514"

0.875" 62 F100 rear piston diameter 0.601"

0.9375" 76 f150 rear piston diameter 0.690"


62 F100 front brake ratio 6.78:1 total 75% bias

62 F100 rear brake ratio 4.62:1 total 25% bias

76 F150 front brake ratio 49.8:1 total 90% bias

76 F150 rear brake ratio 5.28:1 total 10% bias

Current setup front brake ratio 31.8:1 total 90% bias

Current setup rear brake ratio 3.36:1 total 10% bias

Math that I sorta understand but did it just because

​​​​​​Assuming a 50 lbs of foot force on the brake pedal (which is moderately heavy braking as I understand it) these are the pressures and clamping forces of the 62 F100, 76 f150, and my assumed current setup. I believe that the large bias in the 76 and therefore my brake setup is tuned by a proportioning valve? But I am not 100% sure on that.

62 F100 front psi 225, clamping force 239 lbs
62 F100 rear psi 75, clamping force 66 lbs

76 F150 front psi 344, clamping force 991 lbs

76 F150 rear psi 38, clamping force 36 lbs

Current front psi 220, clamping force 634 lbs

Current rear psi 24, clamping force 22.5 lbs

Final thoughts, due to the larger piston size in the hydroboost compared to the master cylinder I believe this will result in a more firm brake pedal with a shorter throw. I have no idea how much shorter as I don't know of a way to calculate that.

 

You have a system installed, hopefully free of air and ready to go. There is no loss in trying it. My worry is if there is ever a "spongy peddle problem" where to start...

But, try what you've already got, and keep the 90° bracket as a back up plan that can remove several possible problems.

 

So much got done since my last post, finished painting the interior cab, then put down the 2 layers of sound deadening, put the carpeting in to make sure it would work but had to remove it to flatten it out some and do some work in the cab still, got the front bumper 90% complete, modified it a little to not only look better but also allow for 2 functional tow points. Ended up using a 76 rear step bumper as the side bumper pieces because I had it lying around and I love the Way it looks. It will also provide a nice platform for working on the engine if I need it. I finally got the alternator and power steering bracket finalized with room for a ac unit whenever I get around to that. I found an old gmc avionics rpm gauge that fits the tach cable connection and has the right rpm swing. I just hope it's the correct gearing to match the engine rpm. We will see. I also made custom reducer 90's to replace the very old worn out ones on the motor, had to make them because I couldn't find a non-silicone 1.75in to 1.5in tight 90 radiator hose. I used rtv on the reducer just to help everything stay in place. I also installed the wiring harness I made a while back finally, just have to make all the end connections and probably add the 20 wires that I forgot existed before that's good. I also discovered that double U joints and rag joints do not play nicely at all in the steering setup. So I ordered a second heim joint and a standard U joint to replace the rag joint. All in all its coming along nicely.

Front bumper, winch can still technically be removed and installed in the rear with this setup thou it's still a 150lb chunk of metal lol.

Plan is to try a slightly darker silver color on the bumper, having the platforms on either side of the winch is nice thou I do miss the original idea I had where both sides would have storage, I just couldn't use the original winch bumper sides due to geometry


Ended up using a large piece of 3/8in angle iron for the bumper mounts, bolted to the frame with 3/4in structural bolts because I had them lying around lol

Bumper mounts final welded and painted with front shackles installed.

Somehow got super lucky cutting out the access for the transfer case shifters, carpet lays down nicely but had obviously fold marks I want to flatten out before final install

I will need to fabricate some kind of step tread hold down as the only ones I can find for sale are billet aluminum and expensive

Wiring harness going back in. That was a nightmare. Never again!

Custom radiator hose for waterpump to header connections

Final and ready to install, just waiting to throughly dry out
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Awesome rpm gauge that hopefully will work.

Rag joint got destroyed while I was testing. Worked fine when unloaded, but once I connected the tires up it bound and snapped. Glad I found out now and not down the road.

 

That rag joint is likely just cheap import junk... I don't see any hint of fiber reinforcement, original's would have been fiber reinforced... The strength difference is huge!

 

I found that suspicious as well, I ordered it from ebay from a US seller and had assumed it would at least work for mockup and testing but yeah I noticed it was clearly an unsafe part as it only had an illusion of reinforcement.

 

I usually get them from the local parts store. The Dorman ones have always worked well for me. They are usually on the aisle with all the universal stuff, trim clips, shock bushings, etc.

 

Finally finished the electrical, had a few snags like a broken connector in the middle of the loom causing my left turn to not work at all. I got the gas tank installed along with the filler neck. I built a gauge mount with a switch for the hazard lights that mounts to the steering column. I ended up removing the old remote mount brake booster system due to concerns about complexity. I ended up going with an angled bracket to fit it. Not finished yet but wanted to make sure the proof of concept would work out. I ended up finding a low profile fan that barely fits. I also got my driveshafts built, they were able to find a flange yoke that fits the transmission output for the parking brake drum piece. Had to upgrade to a 1410 U joint for that side as that was the only option. It is for a dodge truck, I'll get the part number in here when I find it again. I ended up swapping out the radio for a newer but still old one. In the process I accidentally scratched the paint above the radio when filing down the burrs and ended up placing the hazard light in that location. I finally got around to welding the exhaust after setting up my tig, got half of it done so far.

Wiring is getting tidier, still need some work but getting there.

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Only have around 5/8ths of an inch gap between the fan and the radiator, sure hope the engine doesn't move haha.

Gauge mount, held with a hose clamp

Driveshafts back from the shop, glad I went away from building my own.

Fuel filler neck from the 76 f150 happened to line up nicely, slightly off center but I can live with it for free.

Going to build a fold down license plate holder to cover up the gas cap.

New location of the hydroboost booster, just barely fits

Connection assembly is 1 to 1 ratio but can be adjusted slightly with off camber bolt


Driver side exhaust welded up, took all day but got it done. Just need to find where ever I put my stainless steel strapping to make the hangers.

Welds turned out way better than I expected after not having tig welded in 4 years or so, and having done very minimal stainless steel welding. Pipes were back purged as well.

Clearances between the front drive shaft and exhaust is pretty good. Now I need to cut and build the passanger side.

 

Just read this from start to finish. Nice work. Looks like a nice space to work in. Keep the pics coming.

 

Thanks, yeah I'm trying to share as much as possible for others to get ideas and to help that one person 10 years from now who wants to copy something I did lol.

 

Finally to the point where she runs and drives. Lot of items remaining but I pushed hard to get to this point to meet my move deadline and to build motivation to finish it up. Had so many issues, firstly on my first drive my oil pan had leaked terribly. When I had put the Rtv on it I had not put enough and had waited too long to bolt it up which caused me to lose a gallon of oil in about 30 min. Later also found out the remote mount Oil filter hoses were both leaking at the swivel joint. Took it to a hydraulic shop and they said those swivel joints wouldnt seal until at least 1500 psi was in the lines. No clue how they didn't leak for the previous owner. Had a nasty fuel leak as well from the fuel return line hose clamps not being tight enough. Spent about 8 hours bleeding the injector pump only to realize that I had installed the lifter pump after the fuel filters which is apparently a big no-no. Finally got it started and it sounds great. There's a metal on metal sound in the videos that ended up being a front quarter panel support piece that was rattling against the frame so don't worry about that noise. Truck sounds perfect, I was afraid it was going to be too loud but the muffler and resinator tuned it down very nice. I wont know exactly how quiet the cab is until I can install the back window, just waiting on my friend to get back to help me out. I got the headliner installed and it's... Loud. Lol. Plan is to paint it but for now it will work nicely. The Rpm gauge is accurate thou due to being mechanical it is very wishy washy when registering big changes but overall I love it.

Videos
First startup
Outside walk around
Out for a drive




Flip down license looks good, may need to move the license plate light thou.

Installed the Toro-flow badge, just need to make a spacer to fill the gaps




Bumper and winch finally finished and looks great, the platforms make engine work really easy lol.

Headliner is a bit aggressive but it doubles as a mirror 🤣
decided to go with a foot operated windshield washer pump for the novelty and the fact that it ended up costing about the same as installing and electric version

Washer bag location

She finally sees daylight for the first time in over 6 years

 

Badass. The work was worth it from my vantage point.