Power Brake Upgrade for 66 F250

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Aubrey3
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Power Brake Upgrade for 66 F250

Post by Aubrey3 »

I have a ‘66 F250 2wd V8 Camper Special with drums and manual brakes. My next project is to upgrade to power brakes with a brake booster. I’ve read a lot of posts and have read a lot of recommendations and cautions. I am taking these items in pieces to spread out some cost and to evaluate each step to see if I need to keep going farther. Eventually I may go to ’74 dual piston discs up front, but that may or may not happen depending on how the rest of this project goes. I have a few questions before I get started.

My first thought is to just get just the booster. Napa has a ‘66 booster that is 7” for $114. They also have a ‘74 booster that is 9” for $134. My thought is to go to the ‘74, but here are my questions.

Will the ‘74 require an adapter plate to the firewall?
Will the ‘74 require some kind of rod change to the brake pedal?
Will the ‘74 work with my ‘66 master cylinder in the meantime?

My second thought is to do both the booster and master cylinder. Napa has them as a package, but I’ll list some items here separately, so I can keep my questions straight. Napa has a ‘66 rebuild that has a 1” bore for $70. When you get into the ‘74 the options change significantly. There is a 1” bore and a 1.25” bore. The larger bore seems to be for dual piston calipers only. The 1” bore is available for manual or single piston calipers. The 2wd trucks seemed to have all been discs where the 4wd trucks had an option for discs or drums. And then there are different line thread sizes available (3/8 vs 9/16) which is tied to the bore size (1” bore = 9/16 line thread, 1.5” bore = 3/8” line thread). These master cylinders range from $36-56 depending on the configuration and if new or remfd.

Will either bore size matter if I stay with drum/drum for a while?
If staying drum/drum for a while would the manual, single piston and the dual piston caliper m/c work ok? Or would the dual or even the single cause the fronts to lock up too fast?
If staying drum/drum for a while, which one of the master cylinders would work without adding a separate proportioning valve?
I saw a post for a T-fitting to use the stock brake light switch with a dual pot m/c. Has anyone tried it successfully?

The project…
1. I want to get just a booster to add to what is stock, so I don’t have to worry about a brake light switch and a plethora of other parts.
2. I want to get a dual pot master cylinder for just drum/drum, so I don’t have to worry about all the front disc setup yet.
3. I may, down the road, go to a ’74 dual piston front disc setup.
1966 F250 2wd V8 Auto Camper Special Custom Cab
bruceandersson
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Re: Power Brake Upgrade for 66 F250

Post by bruceandersson »

I've upgrade a number of the slicks to mid-70's disk brakes, but it has always been complete at the same time. I've always been after better braking and the safety of a dual system. Mine were always 100's not 250's, but the process should be the same, your parts are just heavier. Replacing everything at once is less than a days job. Each time, I did it the cost was less than $300 as I found some good used parts. If you go with the 66 booster, hopefully it will work without modification with your current setup. I may or may not work with a dual master cylinder if you continue the process. The same goes for the later booster and your current M/C. I've always had to move the hole on the brake pedal arm where the rod from the booster connects. The boosters bolt on directly. I've moved the hole by welding the old hole in and re-drilling. Check out the www.fordification.com web site for some good info on upgrading to disks. This covers the 67-72 trucks but applies to slicks as well. Only difference is that the 67 on trucks were already dual cylinders. My advice - do it all at once and have some really good brakes when you are done.
Aubrey3
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Re: Power Brake Upgrade for 66 F250

Post by Aubrey3 »

Thanks for the extra info.
For the firewall bracket, is it something like in the picture of mine or is it more of a riser?

For boosters with a flat rod (and others) I have found some boosters with a threaded rod on the booster side and a threaded banjo bolt that threads in or on to the booster rod. This would give some adjustment in throw, although I am not sure by how much. With that said, there are two full setups on ebay (not that I’m a big ebay buyer) that I’m wondering if they will work pretty easy. One is an 8” dual diaphragm booster and the other is a 7”. The 8” setup is for a ’61-’72 Galaxie and the 7” is for a ’64-’66 Mustang. They are from Nelcohotrods. It says they can do any brake configuration with the right prop valve. Ah… just found one of theirs for ’57-’72 F100 with 7” booster 1 1/8” bore and says to bolt right up.
http://www.ebay.com/itm/1957-1972-Ford- ... 4d2b21fba6
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1966 F250 2wd V8 Auto Camper Special Custom Cab
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banjopicker66
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Re: Power Brake Upgrade for 66 F250

Post by banjopicker66 »

By the way, Welcome to Slick 60s. You'll find no better place or bunch of people.

First of all, you cannot add just the booster. There is a bracketry support that bolts to the firewall for the booster, and sits between the pedal and the booster. You will need acquire this from a donor truck.
There are several types out there. I recommend you look for the one with a flat rod that connects the brake pedal to the booster. It is easy to redrill the hole for the brake pedal bolt. (The distance between the brake pedal and the firewall in the '70s trucks is longer than in your '66. That rod - or flat blade has to be shortened.)
You can use the '66 master cylinder on the later booster IF you can remove the brake pedal rod and use the pushrod in the front of the booster, the one between the booster and the master cylinder. It will require some adjustment and testing to get it right, though.
The Feds required all cars and trucks (with some few exceptions) to have front disc brakes in '73, so you will not find F-100/250s with front drums.
As for the NAPA master cylinders, the larger bore is indeed for larger volume, to activate the dual front piston calipers. You will definitely need that if you go to the heavier duty disc brakes.
You should be able to use the larger bore master cylinder with drums, but your pedal travel will be less, and will sit up quite high.
You MUST use a master cylinder for drums with drum brakes. You must also use a disc master cylinder with disc brakes - do not mix and match drum-disc parts.

This is what you need:

Image

I bought a donor truck, and harvested all the parts to do the upgrade from it, and that is my recommendation as well. It really saves a lot of frustration, money and time, especially looking for the little piece you really really need that cannot be obtained from the parts store.
With the donor truck, you get the spindles, brake lines for templates to make your own, and you can use the calipers for cores if they are no good.
(Then, part out the donor truck for parts you do not or cannot use, and get a good amount of your money back!)

There are several different kinds of booster support brackets. This one came off a '78 F-250. You cannot see it in the picture, but there is a pivoting lever inside the brackets, between the brackets' supports. Not sure what the purpose for that is, but it is what came with the donor, so I used it. I think the purpose was to raise the booster up higher, so it didn't interfere with the valve overs of the engine, which was a 400.
Other supports are different. Some do not have the pivoting lever, some have a round rod instead of a flat pushrod, but any of them '68-'79 will bolt up to the firewall on your '66.

Aubrey3 wrote:For boosters with a flat rod (and others) I have found some boosters with a threaded rod on the booster side and a threaded banjo bolt that threads in or on to the booster rod. This would give some adjustment in throw, although I am not sure by how much.


The booster side adjustments are not for adjusting the throw of the brake pedal rod. They are instead for minimizing the slack between the booster and the master cylinder.
Too much slack and your pedal will go to the floor with little or no braking, for example.

The banjo bolt at the brake pedal allows of a very small adjustment of pedal travel, but less than an inch, based on my experience.
It is best to set the pedal rod to its optimum length first, and then use the banjo bolt to make fine adjustments.

John - Banjo :hello:
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Toyz
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Re: Power Brake Upgrade for 66 F250

Post by Toyz »

There are some good on-line tutorials around. I would strongly recommend upgrading to the dual booster at this time, not only for safety, but in case you go ahead with further upgrades. You CAN utilize a later dual master for the drums, then use it for discs if you upgrade. On the F250, my suggestion would be the later F250 master, although it will lack the front residual valve needed for the drums. It is very easy and economical to add an in-line 10 psi residual valve since you would be re-plumbing at the m/c for the dual system. Some of the later masters do not have either front or rear residual valves for the drums; those are typically mounted in the "combo valve". If that is the case. choices are 10psi valves front and rear, or an OEM style combo valve. These keep shoes in close proximity to the drums, requiring less fluid movement before activating. Some people are willing to trust that function to the self adjusters; they WILL NOT maintain that close proximity; and both Ford and I feel they are needed!
Setting up a booster/ m/c not designed as an set is a little tricky, whether using the original m/c or upgrading. Your new master cylinder may come with a sheet showing critical dimensions; most do not.ore for the booster actuating rod, measuring from a straight edge across the housing at the part which fits into the booster. Then measure the master cylinder housing from the same point to the cylinder mounting flange. Next, start the engine with master cylinder still removed and booster hooked to vacuum. Measure the booster output rod from flange to end of rod. It needs to be adjusted to the dimension taken from the rod depth found on the master cylinder, minus the measurement from end of casting to mounting flange.
All this should have had a confusing effect; however, it is important in helping to set up a dependable braking system!
Paul
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Toyz
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Re: Power Brake Upgrade for 66 F250

Post by Toyz »

I would stay with the 1" master, even if you go with the multi piston calipers later. NAPA is correct, the 4x4's did have drum front brakes. That master/booster combo would suit your needs well with the drums, and still allow later upgrade. proportioning valves help; you can plumb them in later if the need arises; the factory combo valve has that function, as well as other worthy functions, although not readily adjustable.
As Bruce stated, finding a donor for parts such as the brackets, combo valve lines, fittings, etc., is an easy and usually less expensive approach. If you still go with the new booster/master, the core value of the donor parts will reduce the cost. The adapter fitting for the pressure switch works well, just be certain not to run the "low-pressure" switches if you have an in-cylinder residual valve, for obvious reasons. I prefer to install it on the rear lines, specifically due to front delay functions built into the combo valve, if used.
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F164
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Re: Power Brake Upgrade for 66 F250

Post by F164 »

Bumper2Bumper sells a booster/MC that is correct for our trucks. You will still need the 65-72 firewall brackets.

The 73-79 brackets fit just as well and are much easier to get.

IMO there is no need to upgrade to a dual pot MC or discs until you need brakes or kingpins. These trucks have made it 50+ years with a single pot and drums all the way around, they can make it a few more.
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Toyz
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Re: Power Brake Upgrade for 66 F250

Post by Toyz »

Or not! Personally, I would much rather have "half" a brake failure than a complete one. I suspect most people within a close proximity of the vehicle being operated with those potentially 50 year old parts would likely share that feeling!
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Re: Power Brake Upgrade for 66 F250

Post by chris401 »

lf you have a FE 352/390 with tall after market or hiperformance factory valve covers you'll want the 7". The common factory covers(nonadjustable rocker arms) may come off with out problems using the 9".
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Re: Power Brake Upgrade for 66 F250

Post by F164 »

There is already a dual brake system.

Foot brake / hand brake
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Toyz
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Re: Power Brake Upgrade for 66 F250

Post by Toyz »

RIGHT!!!!!!
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Aubrey3
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Re: Power Brake Upgrade for 66 F250

Post by Aubrey3 »

So, to keep this simple, I need:

65-72 Firewall Bracket
72 Brake Booster 7" Single Diaphragm
72 Master Cylinder for disc/drum or drum/drum

Right?

I just stopped by the local yard and he said I need to do measurements of everything because the different years had different firewall bolt patterns, different lengths and types of rods, blah blah blah.
1966 F250 2wd V8 Auto Camper Special Custom Cab
Aubrey3
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Re: Power Brake Upgrade for 66 F250

Post by Aubrey3 »

Or just a '66 power booster, leave my master cylinder, and find a '65-72 firewall bracket.
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1966 F250 2wd V8 Auto Camper Special Custom Cab
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Toyz
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Re: Power Brake Upgrade for 66 F250

Post by Toyz »

The local yard is making it a little more complicated than it is, especially if you can find all items from a single donor. I do not know if your master cylinder will work with a booster. If so, there should be a plastic "bumper" in the master cylinder piston which will need to be removed. Only way I know for certain if your master will work is by removing and measuring the depth and comparing to the adjustable rod on the booster.
Paul
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