Is there a difference between power front disk brakes and just plain front disk brakes other than the vacuum booster? That is to say, if I find a vehicle with front disks and no power booster, can I take those parts and then just add on a new power m/c?

Dan Blackwell

 

Dan I believe that all the front discs are Power brakes.

Again if that isn't correct we'll soon find it out.


John
jowilker@nc.freei.net

66 F100s
In the still cool hours of the night, you can hear chevys rusting away.

 

I have not seen a Ford truck with front disk brakes that were not power assisted. I have driven other vehicles that had disk brakes that were not power assisted though. (Ford Pinto comes to mind.)

 

Dan, I have seen several trucks with just discs on front (no power booster). In fact the 73 Ranger XLT my dad owns is "non-power" front discs.
I beleive the only diff is the booster and possibly the poportioning valve (valve that equalizes the pressure to wheel cylinders).

Vic

 

My '73 F100 came with manual disc brakes, so did my brother-in-law's '78 F150(both 2wd). I've seen several others like that too, I think it was fairly common.

I added power to mine, I just got a booster off of a '79 and it bolted right up, no other changes. I've ran it like that for over 2yrs with no problems.

Marty

 

Many thanks. I was looking at I-beams with disks on a wreck last week that didn't have the booster on the m/c and probably will go back and get them now. DB

 

Sorry for digging up this old thread but I’ve been curious and did a little research. Starting in ’73, front disc brakes became standard equipment. On the F100, the power booster was optional, on the F250 and up the booster was standard. Well, that’s about it, you can push this thread back down again!

Barry

 

>push this thread back down again!
>

Let's don't get rid of it too fast. I'm slow at getting stuff together sometimes so this gives me the opportunity to dig deeper into what I'm going to need. I have a disk brake front end ('78) in the yard. I'm going to check it all out tomorrow and replace what needs it. I don't yet have the booster or the pedal #####'y and BBB's post makes me wonder if I'll be able to use my existing master cylinder ('68) and just add the big ol' booster cylinder in front of it. Or is the mc different, too?

Thanks,
Dan Blackwell

 

I have a '74 F-100 and my power booster went out a few months ago. I went to the scrap yard and noticed a difference in almost all of them, but was unsure of the performance difference. So, I took one off a '79 150 and it was the same diameter, but yet it was thicker by about an inch I think. It bolted right up; however, my brakes are...lets say...super power compared to what they used to be. Yet I have had no problems other than a heavy foot first thing in the morning, but that heavy foot and those super brakes give me the wake up I need to get going everyday! Beats the hell out of coffee!!!!!

 

Dan, the master cylinders are different, the drum master is 1” inside diameter and the disc master is 1 1/4". I am in the middle of the same swap on my ‘68. Now something I don’t have a handle on is the correct booster to use. Up to ’72 there were two different boosters used, a 6 ¾” diameter unit and a 9” unit. The smaller one has the pushrod from the pedal going straight into the unit while the large one has a hinged lever setup instead. My Ford truck literature states the smaller one was used on all ’67 models and made a big deal about the new larger one that replaced it in ’68. I’m not sure about that because I’ve seen both types on all different models and years of trucks in the yards. I’ve bought them both along with the pedal and bracket assy. for comparison. As far as I can tell, both the pedal assemblies and the under-dash bracket are identical to my ’68 meaning they both would fit. Am leaning towards the 9” unit.

Barry

 

I can get a rebuilt mc for $18. A rebuilt vb from the same place runs $105. I'm trying to put as much new/rebuilt stuff into my truck as I can swing but $105!? I don't want to cut any corners where safety's concerned so if I can find a vb in a yard would it be likely to work. Obviously, I won't know how long it's been idle or how it was performing before its truck got dumped. So my question is really, is there rubber to dry out or other parts that might rust or whatever that would make a salvaged unit a high risk?

This is getting expensive. $150 for the front end, $70 for the calipers, $80 for the rotors, $22 for bearings and seals. Brake lines, pedal, and installation yet to come...but it is fun. Shoot, Pop drove the truck for 28 years, why shouldn't I?

Dan Blackwell

 

Dan, as far as safety is concerned, it’s hard to say anything these days without the potential liability. I’m not to enthused about rebuilt master cylinders though. If the booster goes out you still have brakes, albeit power leg brakes but when the master goes out (and a rebuilt one will) you have no brakes period. Another thing to consider, they sell rebuilt boosters with the correct master cylinder as a set that might be cheaper than individually.

I would check the boosters in the yard first, I got mine for $25 which included the outside and inside brackets and pedal. If it doesn’t work you can always buy the rebuilt unit and use the yard unit for the core charge of around $25 so you are still even. As far as picking one from the yard, I would avoid those that have brake fluid inside from a leaking m/c, tranny fluid in the vacuum port, cracked pushrod seal or have rust on the pushrod or inside. I use a hand-held vacuum pump w/gauge to check the booster before pulling it.

Have found out a little more application information. The 6 ¾” booster was not used on any of the disk brake options. The 9" booster was optional from '68 thru '70 for drums and mandatory for discs. Also there was a 3rd booster starting in ’71 with an 8.8” diameter. It is a dual-diaphragm type while the other two are only singles. The ’71 and ’72 disc brake trucks use this booster while the drum trucks still used the 9” except for the F350 which uses the 8.8” unit on all brake options. Aside from the three factory boosters used from ’67 thru ’72, there were dealer-installed units that were different plus a few aftermarket units too! Confused yet?

Barry

 

 

I've had pretty good luck with auto wrecker boosters myself. Stick with 68 and up though, because the pushrod and pedal assembly are different on the 67's. Any booster from 68-79 should work even with the above noted physical differences. The master cylinders from 73-79 had their lines coming out on the opposite side from the earlier ones. Remember to change the proportioning valve on the frame when you do this swap and check out the article in the tech section of this website for more info.