I don't want to upgrade to disc brakes right now, as I think my drums are fine, but I've thought of upgrading them to power.
I've read a whole lot on here and other forums of people upgrading, but I can't really get a clear picture of what I need. Some say I need a bracket from the junkyard. Some say I just bold the booster to the firewall. I can't determine if I need a new MC. Most say no, but there's a different one listed for power vs manual at the auto parts. There's also lots of talk about pushrod length and pedal height. Some say that adding a booster makes the brakes way too sensitive.

Can someone shed some light on this for me?

 

Is this going on one of your '70 F100s?

 

Yes, it is.

 

There were both single and dual diaphragm boosters available in the '67-'72 Bumpsides as well as the '73-'79 Dentside trucks --however, there were more variations to the boosters and mounting brackets in the Dentside trucks than in the Bumpsides.

All the Bumpside and Dentside trucks had boosters that were mounted to firewall brackets. None of the boosters in the 5th and 6th generation Ford trucks were mounted directly to the firewall.

If you get a donor booster/brackets from a Bumpside, you need to get them from a '68-'72 model. If you get them from a Dentside, it's best to stick with '73-'77 models. Lots of changes to the boosters/brackets occured in '78/'79 that can make it more difficult to install them in the older Bumpside.

When I bought my truck in 2011, it had manual drums all the way around. Less than a year later, I installed a dual diaphragm booster/brackets from a '75 F350. I turned the booster in as a core at O'Reilly's for a newly rebuilt booster (p/n 54-73112).

I had installed a brand new 1.00" bore cast iron MC right after I had bought my truck. When I added the booster, I just transfered the MC I had bought less than a year earlier over onto the booster. I figured the brakes would be somewhat sensitive with the combination of a small 1.00" bore MC, a powerful dual diaphragm brake booster and 4-wheel drums. I was right.

I drove my truck for the next two years like this until I removed the '69 F100 drum brake front suspension (in 2014) and I replaced it with a disc brake front suspension from a '77 F100. It was also at this time that I removed the 1.00" bore cast iron MC and replaced it with a (new) more modern 1-1/16" bore aluminum MC for a '95 Ford Explorer.

Switching from power drums to power front discs is without a doubt one of the single best things I've done on my truck. My brakes were not great when they were manual (and I understand how to service/set/adjust drum brakes). They were better, albeit sensitive, when I added the dual diaphragm booster when I still had 4-wheel drums but, the single greatest improvement came when I dumped the front drums and changed the truck over to front discs. My '69 F100 stops exceedingly well now.

If you plan to remain with drums all the way around and if you plan to run an OEM booster/bracket setup from a Bump or Dent donor truck, you're going to have to decide if you're going to run a single diaphragm booster or a dual diaphragm booster.

While you're changing things, I would strongly suggest that you replace the MC with a brand new one --NOT a rebuilt MC (it's up to you whether you stay with a cast iron MC or switch to a more 'modern' style MC). The only primary difference between a manual brake MC and a power brake MC is the input/push rod on a manual brake MC has a clip on the tip of the input rod that positively engages (snaps) into a receiver groove inside the primary piston bore at the rear of the MC.

A MC meant for power brakes will not have this groove for a pushrod clip to lock into. The power brake MC bolts to the face of the booster and the output rod from the booster to the MC is retained by the booster so, there's no possibility the output rod from the booster to the MC will fall out the back of the MC.

The other difference between the original applications of the cast iron MCs on these trucks is that a MC meant for all-wheel drums would have had a Residual Pressure Valve in each of the two MC ports, where the brake line fittings would have screwed into the MC. This was to keep a small amount of pressure (approx. 10 PSI) on the lips of the wheel cylinder's cup seals, to keep them in tight contact with the wheel cylinder bores and to keep air from being drawn in around the cup seals and into the wheel cylinder bores, when the brake pedal was being released. A truck with factory discs/front and drums/rear would have had a MC with an RPV in the secondary port going to the rear drum brake circuit but no RPV in the primary port going to the front discs.

Today, if you go to the parts stores and buy a replacement MC that's exactly like the one that had come on the truck, chances are very good it will not have any RPVs in the ports --even if the original application MC did.

There are no RPVs on the Explorer MC I'm running and I've had no air infiltration problems with the rear drum wheel cylinders on my truck. Back when I had the new cast iron MC, I checked it before installing it and it didn't have RPVs in it either.

 

That's some excellent information ultraranger. It answers all my questions.
I think I might just go to the junkyard and get all the parts to convert to discs instead of leaving the drums then. My drums stop fine, but not too confidence inspiring pulling my 3500# camper.

 

It will require some effort and and also running some hard brake lines to install the discs on the front but, the effort and pay-off will be worth it when it's all done.

I have no regrets pitching the front drums on my truck. As I said, it's one of the best changes I've made on my '69 Ranger.

 

Subscribing.

 

IF you decide to switch to front discs, instead of keeping the front drums, you'll need to find a '73-'79 F100 or a '75-'79 F150 donor truck to get the parts from.

I prefer to swap the ENTIRE front suspension out, rather than just swapping the discs/spindle assemblies. This just eliminates any mix/match problems that can come from not swapping the whole setup over. --I have done two front disc brake conversions; one on my own '69 F100 Ranger and another one on a '72 F100 Sport Custom.

You'll also need to swap out your drum/drum pressure differential brake valve for a disc/drum brake valve and you'll need the left and right frame brackets, (where the hard line and the flexible brake line meet), from the donor truck.

These are some links to the swap I did on my '69 F100 and the '72 F100 belonging to another guy.

(My '69 F100 Ranger)

https://www.ford-trucks.com/forums/1...ont-drums.html

(1972 F100 Sport Custom)

https://www.ford-trucks.com/forums/1...o-booster.html

 

Some of these will also help. I got them from HioSilver's sticky at the top of our page here Read First: Technical Info Hyperlink Compilation ( 1 2) HIO Silver.
65-72 PS & Disc Brake Swap
66-75 Benchworks F100 4x4 Power Steering Conversion
67-72,73-76 Integral PS Conversion Tech Article
Classic Trucks Magazine F100 Power Disc Upgrade
Pirate 4x4 Thread: 9-inch Rear Discs for Under $100
James Duff Enterprises Dana 44 Front & Rear Disc Brake Kits
TSM Manufacturing: Ford 9-inch Rear Disc Brake Kit
Bulletproof Steering Systems- Tie Rods & Drag Links
ND Gearheads: Ford FE with GM Saginaw Power Steering Pump Brackets
CVF Racing: Ford FE with GM Saginaw PS Pump & Alternator Brackets