I have a 1966 F350 dually (dana 70) dump-body, 352, manual 4-speed. I'm looking to replace my Brake Booster and I'd like to upgrade to a dual reservoir Master Cylinder while I'm at it.

Does anyone have any recommendations or favorite particular setups? I'm more likely to go for something new/refurb rather than finding something used, but nothing's ever out of the question.

Thanks!

 

Does your current booster not work or are you just tired of looking at it? I would recommend the '67 dual reservoir master if you're sticking with drums up front.

 

The booster for a 66 F350 is under the cab and separate from the reservoir. That said, I've always wondered the same thing...

Common sense would tell me there's no such thing as a "divorced" booster anymore? And that converting to a '79 F250/350 "married" setup would be the best bang for buck but retain a 4 wheel drums distribution valve from a pre '75 setup?

This is just a guess so nobody run out to NAPA just yet without further input...

 

I'm not certain the booster isn't working, but the brakes feel harder to engage than they should. Also, every once in a while when I hit the brakes there's nothing, then they grab on the second pump. I'm thinking that's the Master Cylinder.

I have a tendency to just overhaul everything as I go for my own peace of mind, hence looking at replacing the booster/MC in one shot. I was given the advice of looking into the dual reservoir MC by someone for safety's sake, but I'm not sure what setup to look for.

My booster is on the firewall/married setup. Are you sure under-cab was standard?

 

Nope. I've came across three 66 F350's and all of them were so I assumed.

If yours is on the firewall then look into swapping for a 73-79 setup. It's been done a million times on here so should be an easy search. I've never done it so I don't have much to offer.

 

Quick research shows a wide array of pedal/pushrod/booster variations for the 73/79 F100/F350. (https://www.ford-trucks.com/forums/1...hrod-code.html)

If I do go that route, I'll have to do some research first to try to narrow down what particular p/n's might fit.

 

Got me bootsmagee...

I would tend to just get one from a '79 F150 (Since that would be the most common)and just make it work by either lengthening or shortening the push rod.

From what I gather from the link you just posted, there's probably not a direct swap from a 73+ to a 66 without some fabrication of the push rod?

Hopefully someone who has done this will help us out for I'd like to do the same thing myself one day?

 

Indeed, if it comes down to it, I could modify pushrods to make things work. We'll see if anyone chimes in with a simpler solution or if I can find any further info.

I also just came across this: https://www.ford-trucks.com/forums/1...nterested.html

It's a way to go about it, but I'm not sure yet how I feel about the cheap-ish parts in the long-run.

 

'78/'79 Dentside donors are generally not the best choice for getting boosters from. Lots of changes to the boosters occured during these two model years. --longer input rods to the boosters that would have to be modified and things of that nature.

The more compatible boosters from the Dentsides should be taken from the '73-'77 models.

I have a dual diaphragm booster (non-bellcrank design) I put on my '69 F100 short bed Ranger in 2014. The booster/brackets on my truck came from a '75 F350 (I turned the donor booster in as a core for a newly rebuilt one). I also recently installed this same style booster on a '72 F100 long bed Sport Custom.

Dual diaphragm booster I installed on the '72 F100 Sport Custom shown in the following link. (If you have 4-wheel drum brakes, you're probably better off with a single diaphragm booster).

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

 

Thanks for the added info, ranger. I have read that a dual-diaphragm booster probably wouldn't be a good idea for all-around drum brakes because the brakes would be really sensitive to pedal pressure. Would you agree with this?

 

In order to get the most potential and the best braking, it would be best to get the front discs off of an F250 donor truck and pitch the front drums.

My '69 F100 had manual 4-wheel drums when I bought the truck in April, 2011. I completely went through all four drum brakes and replaced everything with new parts. It would stop better but wasn't great. Less than a year later, I added the dual diaphragm booster and just transfered the new 1.00" bore cast iron MC, I had previously bought, onto the booster.

I figured the brakes would be pretty sensitive with the combination of a powerful dual diaphragm booster, 1.00" bore MC and all-wheel drums --and it was.

In October, 2014, I removed the '69 F100 front drums/suspension and installed the front discs/suspension from a '77 F100. I also removed the 1.00" bore cast iron MC and installed a new, 'modern' aluminum 1-1/16" bore MC for a '95 Ford Explorer. This was a HUGE improvement to the braking system.

Discs require more input force to actuate than drums but, they have far better modulation (linear application) of the brakes than drums, they are far easier to service, don't have a tendency to grab and make the truck veer to one side or the other (vehicle tracks straight when the brakes are applied) plus, they're just way cooler looking than drums.

If you're getting parts from a donor truck, stay away from '67 models. The '67 Bumpside had a number of one year only items on it and the brake booster is one of them. Best years for donor boosters/mounting brackets is '68-'77.

There are two basic booster mounting bracket configurations; non-bellcrank type and bellcrank type. The booster in my truck is the non-bellcrank type meaning the input rod on the booster connects from the back of the booster and directly to my '69 brake pedal.

The bellcrank type will have an input rod that connects from the brake pedal to the bellcrank assembly. The booster will have a short input rod that goes from the back of the booster to the other end of the bellcrank assembly.

Either bracket arrangement was used on the single and dual diaphragm boosters.

My truck after I had added the dual diaphragm booster (with the 1.00" bore cast iron MC) and I still had drums all the way around.



This is after I had replaced the front drums/suspension with the disc brakes/suspension from a '77 F100 and I changed out the cast iron MC for an aluminum one.



Examples of a single and a dual diaphragm booster mounted on a non-bellcrank bracket assembly.

Single diaphragm booster.


Dual diaphragm.


Examples of a single and a dual diaphragm booster mounted on a bellcrank bracket assembly.

Single diaphragm.


Dual diaphragm.


If you have a non-bellcrank type mounting bracket with a single diaphragm booster on it, the booster can be swapped out to a dual diaphragm booster, using the same brackets. Conversely, if you have a bellcrank type mounting bracket with a single diaphragm booster, you can swap out the single diaphragm booster for a dual diphragm booster that's designed for a bellcrank bracket assembly.

A non-bellcrank type booster will have a very long input rod on the back of the booster housing. A bellcrank type booster will have a very short input rod on the back of the booster housing.

 

My f350 master mounts differently than the 100s or 250s I had to fab a adapter plate to make a master out of a 85 f350 work. I did not have the stock mounting bracket though.