I've had the truck (1977 F100) now for about 2 1/2 years.
It has power brakes - front disk and rear drum.
The brakes have not been very good since i purchased it.
Now there is some evidence of fluid dripping from the booster where the master cylinder meets the booster.

I am going to replace the booster and maybe the master cylinder too.

The current booster is apparently Bendix. This is based on what i have found online based on the #'s stamped on the booster (3106873, 3110031, 3083698).

Is there a suitable after market booster and MC that is s direct replacement that will bolt right in without modifications?

Thanks - see pics below






Bendix booster and Master Cylinder - note leak coming from middle of booster.



#'s stamped on the booster

 

What I have seen on here is the '79 F350 booster/mc conversion. The booster is a dual diaphragm booster and the mc can handle the bigger brake that come on the F350. This is great if you decide to disc the rear.

 

Is the '79 F350 booster/MC a direct bolt in replacement on the '77 F100?
Or are there modifications required?
If it is a direct bolt in replacement - do i just order any OEM booster/MC for the '79 F350?

Thanks

 

Remove your single diaphragm booster and install a 54-73311 short input rod dual diaphragm F350 booster on your existing firewall brackets.

There was a 1-1/16" bore cast iron MC available for the '78/'79 F350 that's available new through the local parts chains or, you could install a more modern 1-1/16" bore aluminum MC for a '95 Ford Explorer --you will need to fabricate some lines for the Explorer MC that have ISO metric bubble flares.

 

Technical Info Hyperlink Compilation

Have you searched through this thread? There is a load of info here to help you do upgrades.

 

I installed a (long input rod 54-73112) booster/non-bellcrank brackets from a '74 F350 in this '72 F100 just a couple of months ago (in the FTE link below). The wrecking yard donor booster was used as a core and a newly rebuilt booster was installed. A more 'modern' (new, not rebuilt) aluminum 1-1/16" bore '95 Explorer MC (NAPA p/n M3246) was also installed.

This setup doesn't use the bellcrank style firewall brackets and the booster has a long input rod (compared to the short input rod 54-73311 dual diaphragm booster version) but, you get the general idea.

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

This is a (non-bellcrank, long input rod) '75 F350 booster/brackets I installed in my '69 F100 back in October, 2014, along with a '95 Ford Explorer MC.



If you were wanting to replace your single diaphragm booster with a short input rod bellcrank style dual diaphragm booster (using your existing firewall brackets), this is the booster you would need in the following link.

https://www.napaonline.com/napa/en/p...311/NBB5473311


New, 1-1/16" bore conventional style cast iron MC.

https://www.napaonline.com/napa/en/p...233_0194774841

 

WOW - that's what I need!
I'm going to order both parts and install.
Do you have and special suggestions for the removal and install?
Thanks to all for the guidance.

 

Another question - is that MC compatible with my original pro portioning valve? And I currently have hard lines from the MC to the proportions valve. do I need new hard lines or do you think my existing will fit the new MC?

 

The 350 MC has the hard lines coming in on the driver's side, so you will have to tweak them or make new ones. I can't remember, but I think you need a fitting adapter for one of the lines as well, but don't quote me on that. As far as the prop valve, 150 to 350 shouldn't matter. It will function the same.

 

This might help????

https://www.ford-trucks.com/forums/1...e-upgrade.html

 

I hope whatever booster/master you pick solves your weak brakes problem.

I think the stock system works pretty well at least with near stock size rubber. If your brakes are weak, could there be another issue besides booster/master?

 

The 1-1/16" cast iron MC I presented a link to was used by Ford on the dual diaphragm boosters on the '78/'79 F350s. The 'modern' Explorer MC also has a 1-1/16" bore diameter. The aluminum MC weighs nearly 1/4th what the cast iron MC weighs, it doesn't rust inside or out and it doesn't require the removal of the lid to see how much fluid is inside. The less a cap has to be removed from the MC, the less air, moisture, dirt or debris is introduced to the brake fluid and the rest of the brake system.

With either MC, at minimum, you would likely have to run the two hard lines from the MC to your existing disc/drum brake valve. In the case of the cast iron MC, you would need SAE inverted flare fittings at each end of the two hard lines between the MC and the brake valve.

In the case of the Explorer MC, you would need ISO metric bubble flare fittings at the MC end of the hard lines and SAE 45° inverted flare fittings at the brake valve end of the two hard lines.

The standard size brake line fitting for 3/16" brake tubing is 3/8"-24. However, Ford also used larger sized fittings of 7/16"-24, 1/2"-20 or 9/16"-18 on the MCs and the brake valves but the center hole in these larger fittings is for 3/16" tubing. Most parts stores do not carry these specialty sized fittings and will point you to the fittings adapter bins.

Adapters don't look professional and they just add another connection point in the brake system that can potentially develop a leak in the system. These specialty sized fittings are available brand new so, there's really no reason to use fitting adapters.

I purchase these specialty sized fittings through Classic Tube.

The 7/16"-24 fitting is p/n ST8006.

1/2"-20 fitting is p/n ST8007.

9/16"-18 fitting is p/n ST8010.


The Explorer MC will require an M10 x 1.0 bubble flare fitting on the primary port. This fitting is p/n ST8036. The secondary port will require an M12 x 1.0 bubble flare fitting and is p/n ST8040.

The gravel guard (the spring-like material I used on my brake lines) is also available from Classic Tube. It's available in OE coated steel or also (for more money) in stainless steel. I use the OE steel for 3/16" diameter lines. It's p/n AG1435OE.

 

I really appreciate everyone's input.
Ultraranger - I think I'm going to go ahead w the explorer MC. Thanks for the part #s for the tubing and fittings, etc.
Hopefully when I get this done, I'll have some nice relaxing able braking for awhile.
KG

 

My original system calls for type F fluid.

With a Frankenstein system of '78/79 F350 booster and wheel cylinders, '95 Explorer master cylinder, 73-78 thunderbird calipers, would i still use type F or Dot 3 or Dot 4 or ?

 

Use dot 3 or 4.

Type F is tranny fluid.