Master cylinder, confused

[Ktmracer]

I have a '70 F100, 240-6, 3 spd, and I purchased a 1979 I beam setup/discs, sway bar, yay. I have a manual drum master cylinder now of course. I am confused as to what year or a master cylinder that I need to purchase as I convert to this '79 disc brake setup? I've seen some posts about the linkage problems from brake pedal to the master cylinder connection, but I haven't yet seen the definitive combination or solution to help me.

If its easy to upgrade to power booster at this time, that would be nice to hear about too.

Thanks a lot for any insights.

[ultraranger]

The decision needs to be made if you're going to stay with manual brakes or, if you're going to switch to a power brake setup. That will dictate what master cylinder you need. If manual, get a manual MC for a '79 F-100/F-150. If you're going to convert to power brakes, get a power brake MC for a '79 F-100/F-150.

I have a '69 F-100 Ranger short bed with a 240 and C-4 automatic. It came with manual drums all the way around. A couple of years ago, I added a factory Bendix dual-diaphragm brake booster and mounting brackets that I pulled from a 1975 F-350. I turned the donor booster in as a core for a newly rebuilt booster from O'Reilly Auto Parts.



I have an I-beam/disc brake setup from a '77 F-100 I'm currently in the process of installing under my truck, along with adding a Saginaw power steering gear box (from a '78 Ford F-150), Ford C-2 power steering pump and brackets (from an '82 Ford truck with a 300) a tilt steering column (from a '78 Ford F-150) and a front sway bar (from a '78 F-250 Camper Special).














Your truck will have a drum/drum pressure differential valve (inside the left frame rail, just rearward of the steering gear box). When you switch your truck over to front discs, you'll need to swap the drum/drum pressure differential valve out for a disc/drum combination valve.

Cutaway view of drum/drum pressure differential valve.




Disc/drum combination valve that came with the dual-diaphragm brake booster I pulled from the '75 F-350.




Disc/drum combination valve that I got with the disc brake/I-beams from the '77 F-100.

[Ktmracer]

Thanks Steve for the great post and your pictures! Did the power master cylinder you chose fit the linkage on your brake pedal well?

If I stay with Manual brakes, is it possible to retain my master cylinder and merely pop out its front (pressure) retaining valve?

Steve, I love the details on the power steering. I need to do that project. I also dream of AC too.

Was your truck a factory 240 with an automatic? I wonder if there is an automatic OD transmission that is compatible with our 6?

I was skirting some work by dropping my truck at my local tire & alignment shop last week. Since they don't do 'kingpins', they recommended another shop for me to take the parts to, since one of the kingpins has the cap wiped off, and they were sort of locked up feeling. This second shop wants $450 to replace the kingpins, brass bushings, which includes $120 for the kingpins. Now, I'm wondering, do I really want so much money in factory ibeams, or should I put all this trouble and money into lowered beams? How much money do people usually spend to have their junk-yard disc brake spindles installed onto the Dream beams? $450 still? Or are there no special tools required, no artful bushing work, when you are merely setting up new dropped beams? I'm half guessing that the $450 could almost buy the dropped beams, but I'm not experienced in this yet.

Thanks!!

[ultraranger]

Thanks Steve for the great post and your pictures! Did the power master cylinder you chose fit the linkage on your brake pedal well?

I changed my brakes from manual to power. The booster has its own input rod that connects to the pin on the brake pedal. On the other side of the booster, it has its own (adjustable) output rod that connects to the MC. The following link explains exactly how to adjust the boosters output rod for the specific MC that's being mounted to it.

http://www.maximummotorsports.com/asset ... AK-1r1.pdf

Not all Dentside pickup brake boosters are directly compatible with bumpside trucks or, at least not without having to change out the brake pedal & pedal hanger in some cases. --I didn't have to change my '69 brake pedal or pedal hanger to install the dual-diaphragm '75 F-350 booster.

http://www.fordification.com/tech/clutc ... ackets.htm


If I stay with Manual brakes, is it possible to retain my master cylinder and merely pop out its front (pressure) retaining valve?

If one MC (or brake valve) design was good for all applications, automotive manufacturers wouldn't have produced the different configurations. They are different because they are specifically engineered for the type of brake system they will be operating. A MC for a drum/drum brake system can be used on a disc/drum setup, if there are no Residual Pressure Valves in the MC port that will be feeding a disc brake circuit but, I would advise against using a drum/drum MC on a disc/drum system. Disc/drum (or disc/disc) MCs generally have larger fluid reservoirs compared to a drum/drum MC.

This is because the piston bore of the caliper is larger than the wheel cylinder bore for a drum brake. Disc brake pads are also thicker than the linings of a drum brake shoe. As the disc brake pads wears down, the caliper bore has to be filled with more brake fluid to push the piston outward to compensate for the wear of the pads. That extra fluid reserve has to be taken from the MC. A disc/drum MC has the added capacity to do this but a drum/drum MC, being used on a disc/drum system, does not have the reserve capacity to compensate for this.

Steve, I love the details on the power steering. I need to do that project. I also dream of AC too.

Was your truck a factory 240 with an automatic? I wonder if there is an automatic OD transmission that is compatible with our 6?

My truck came with a 240 and a C-4 3-spd. automatic. The Ford AOD 4-spd. overdrive automatic transmission will bolt up to the 240/300 inline sixes. These engines share the same bell housing to block pattern with the Ford 289, 302, 5.0L, 351W, 5.8L and 351C engines. The AOD was produced from 1980-1993. Pre-'88 AODs had several internal flaws from the factory that were finally addressed and corrected with the '88-'93 models --so, if you're getting an AOD, get one from '88-'93 model vehicle.

I initially thought about going with an AOD but, I'm not really impressed with them. They can be built to be a stout transmission and with some valve body modifications can be made to shift way better than in their stock configuration. However, whatever changes you make to it, that's what you're stuck with unless you open it up to change something else --you physically have to open up the transmission to make the changes.

In '94/'95, the AODE came out. it was an advancement design of the older AOD. Aside from some internal improvements, the main change is that the transmission was no longer controlled through hydraulics (mainly a throttle valve cable). The AODE was controlled through electronics and solenoid valves inside the valve body.

Also in '93, the 3rd generation of the AOD was produced. This transmission was the 4R70W. It was a much better transmission than either the AOD or the AODE. 1998-2004 4R70W transmissions are the best among the 4R70W transmission line. Like the AODE, you have to have a shift controller to handle the shifting of the transmission. Shift controllers for these transmissions can work with fuel injected engines, or with carbureted engines, --if a throttle position sensor is mounted/adapted to the throttle plate lever of the carburetor.

Initial installation of a 4R70W (or AODE) is more expensive on the front end than an AOD but, the 4R70W can be tuned through a laptop or through most of the shift controllers that are available. The transmission doesn't have to be opened up to make changes in the shift points or to the line pressures. The 4R70W also has a much better 1st gear ratio of 2.84:1, compared to the weaker 1st gear ratio of the AOD/AODE which is 2.40:1.

This is my '98 model 4R70W that I pulled from a 3.8L Mustang.

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I plan to install the 4R70W transmission and a 5.0L fuel injected engine inplace of my current 240 & C-4.

The engine shown below (in my '68 Mustang) is a 5.0L H.O. fuel injected engine from a 1990 Mustang GT. It will get transplanted into the '69 F-100.

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...but, as mentioned, the 4R70W can be used with a carbureted 240/300.


I was skirting some work by dropping my truck at my local tire & alignment shop last week. Since they don't do 'kingpins', they recommended another shop for me to take the parts to, since one of the kingpins has the cap wiped off, and they were sort of locked up feeling. This second shop wants $450 to replace the kingpins, brass bushings, which includes $120 for the kingpins. Now, I'm wondering, do I really want so much money in factory ibeams, or should I put all this trouble and money into lowered beams? How much money do people usually spend to have their junk-yard disc brake spindles installed onto the Dream beams? $450 still? Or are there no special tools required, no artful bushing work, when you are merely setting up new dropped beams? I'm half guessing that the $450 could almost buy the dropped beams, but I'm not experienced in this yet.

$450 dollars seems like way too much just to ream the bushings and install the kingpins. The kingpins alone, from the parts store, could be had for $30-$40 dollars less than the price they gave you.

Can't comment on the Dream Beams since I don't have any but, bushings/kingpins would have to be installed same as factory beams. I have the I-beams/discs from a wrecking yard '77 F-100. --then again, if I really want to lower the truck, I do have a complete front suspension from a 2003 Crown Victoria and an IRS assembly from a '90 Thunder Bird Super Coupe. Front and rear assemblies were around $350.00 each.

[ Image ]

Thanks!!