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Converting to hydro-boost; mod'ing pushrod/brake pedal connection & length

CDA 455 II

CDA 455 II

ANFAQUE2
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I'm looking to upgrade my '94 Bronco to a '94 F-350 HB set up.
So far it appears mod'ing the pushrod/brake pedal length will be my biggest hurdle.

What simple way(s) can this nOOB accomplish this mod?

My thought for a simple mod is to weld a bracket on the pedal for the pin where the pushrod hole will be.
Does that sound doable?

FYI:
Rear axle: '87 10.25 dually w/drums
Front axle: stock TTB
 
Looking at '94 F-350 brake pedals on eBay.
They look to be the same as mine, with the addition of a clutch pedal and brake pedal bent to the right to make room.

The pushrod pin appears to be in the same location. 🤷‍♂️
 
Found this on e.Bay:
1699990993123.png



"NEW OEM Ford Truck Hydroboost Brake Pedal Ford F5TZ-2455-A 92-97 Super Duty"
 
F350 doesnt have hydroboost. 450 does.

I drilled a hole in the pedal arm above the existing pin, and threaded it for a bolt, which became the new pin. Cut the old pin off.

Didnt change pushrod length.
 
The pushrod pin is something like 3/4" different, i just cut the weld off of it and reused it.
I'm gunna go look the mod up on o.b.n. and bring it back...
Brb


How to Convert a Vacuum Brake Pedal to Hydroboost Pedal

First, shout out to @laserjock for outlining detailed differences between the pedals, and a few others both here and on other forums that have discussed this. The high level procedure has been discussed and done by many others, but I have not seen a detailed writeup that wouldn't leave you...
www.oilburners.net www.oilburners.net


Moar swap info

Ditch The Weak Vacuum & Upgrade To F-450 Hydroboost Brakes!

the basics,if your not familiar with hydroboost; Hydro-boost power assist was introduced in 1973 by Bendix as an alternative to the vacuum booster. The hydro-boost uses the hydraulic pressure from the power steering system to provide the driver assist in applying the brakes. There are three...
www.oilburners.net www.oilburners.net
 
Last edited:
CDA 455 II said:
Looking at '94 F-350 brake pedals on eBay.
They look to be the same as mine, with the addition of a clutch pedal and brake pedal bent to the right to make room.

The pushrod pin appears to be in the same location. 🤷‍♂️
Click to expand...
Appears to be and is are 2 different things.

I just swapped a clutch pedal set into my hydro boost chevy, it was a vacuume boost assembly. The brake pedal pin was about 3/4" different which was enough to cause issues.

I just wound up cutting the auto pedal pad down and putting it in instead of the one that came with the assembly.
 
If you look at 97 superduty parts then everything will bolt in.

the pin on the pedal you have to move 3/4" i drilled mine and welded it.

You do not have to move it. It will work without moving it but you might have some adverse effects like pedal feel.

In edit, the hardest part to source is the push pin between the booster and the master cylinder. I ended up using just a rod and rounded the ends on a bench grinder.

That length that is needs to be you can google, Too long and it applies the brakes as you are driving. Too short and you are giving up valuable brake pedal travel.
So it can be customized. My first one was too short, way too much pedal travel but what I had found on google. Second was too long and held the brakes on.
3rd one seems to be just right.
 
The pin needed to be moved up on the vac pedal, or the h-boost pushrod binds. Thats 1st-hand experience.

Intermediate pushrod came with my Motorcraft booster.
 
nOOB question:
How about using a spacer plate between HB and firewall? 🤷‍♂️

Since the four HB mounting bolts are rather long; the bolt length dictates plate thickness.
 
Tiha said:
If you look at 97 superduty parts then everything will bolt in.
Click to expand...
1) I'll probably go this route.
Tiha said:
the pin on the pedal you have to move 3/4" i drilled mine and welded it.
Click to expand...
2) As in move 3/4" UP?
Tiha said:
You do not have to move it. It will work without moving it but you might have some adverse effects like pedal feel.
Click to expand...
3) So I can disregard #2?
Tiha said:
In edit, the hardest part to source is the push pin between the booster and the master cylinder. I ended up using just a rod and rounded the ends on a bench grinder.

That length that is needs to be you can google, Too long and it applies the brakes as you are driving. Too short and you are giving up valuable brake pedal travel.
So it can be customized. My first one was too short, way too much pedal travel but what I had found on google. Second was too long and held the brakes on.
3rd one seems to be just right.
Click to expand...
4) If I ordered all parts for a '97 F Super Duty; wouldn't a push pin come with it?
 
You can easily shorten the booster to MC pushrod. pop in lathe (or hand drill) and round off end. It's just 1/4 rod if too short.
Set length so plunger in HB is fully seated but no gap when pedal is at rest position.

The pedal to booster link can be adjusted for the pedal. Some are threaded for this purpose.

I wouldn't pay a premium for a low production OSB superduty pedal. just make what you have work.

Motorcraft BRB33. 99 up super duty
1994 F-350 MC (BRMC38)
6aORZN5xJajLYemCU_6K=w1284-h963-s-no-gm?authuser=0.jpg


e3kPzuc8VppyYQtlcNDN=w1284-h963-s-no-gm?authuser=0.jpg
 

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CDA 455 II said:
1) I'll probably go this route.

2) As in move 3/4" UP?

3) So I can disregard #2?

4) If I ordered all parts for a '97 F Super Duty; wouldn't a push pin come with it?
Click to expand...
#3 you can disregard moving the pin on the pedal until after everything else is done. I drove mine that way for a couple years before I moved it. Maybe I just got lucky but honestly I didn't notice a difference after I moved the pin on my pedal.

#4 As someone else posted they got that pin with their motorcraft HB. I think mine as cardone reman. Can't remember. Of course I did not get the pin with it.
Also I swapped to a different master cylinder than the 97 superduty. When i did that the pin I had in there was not longer the proper length. So I went to making my own anyway.
 
Tiha said:
#3 you can disregard moving the pin on the pedal until after everything else is done. I drove mine that way for a couple years before I moved it. Maybe I just got lucky but honestly I didn't notice a difference after I moved the pin on my pedal.

#4 As someone else posted they got that pin with their motorcraft HB. I think mine as cardone reman. Can't remember. Of course I did not get the pin with it.
Also I swapped to a different master cylinder than the 97 superduty. When i did that the pin I had in there was not longer the proper length. So I went to making my own anyway.
Click to expand...
Found this (new '99 Motorcraft BRB33) on e.Bay:
1700148809733.png


Seeing the pin; I should be good to go; correct?🙏

I should have just the pushrod/pedal 'issue' left.🤔
 
rattle_snake said:
You can easily shorten the booster to MC pushrod. pop in lathe (or hand drill) and round off end. It's just 1/4 rod if too short.
Set length so plunger in HB is fully seated but no gap when pedal is at rest position.

The pedal to booster link can be adjusted for the pedal. Some are threaded for this purpose.

I wouldn't pay a premium for a low production OSB superduty pedal. just make what you have work.

Motorcraft BRB33. 99 up super duty
1994 F-350 MC (BRMC38)
6aORZN5xJajLYemCU_6K=w1284-h963-s-no-gm?authuser=0.jpg


e3kPzuc8VppyYQtlcNDN=w1284-h963-s-no-gm?authuser=0.jpg
Click to expand...
Where'd you get that black plate?🤔

One or two of those would make a nice spacer(s).:grinpimp:
 
+1 on yes...
The short pushrod on the left was hard to come by a few years ago when I did mine.
Looks like it may by reproduced by some today?!
FWIW the pedal pin that's welded to the pedal is not supplied anywhere.
 
Clb said:
+1 on yes...
The short pushrod on the left was hard to come by a few years ago when I did mine.
Looks like it may by reproduced by some today?!
FWIW the pedal pin that's welded to the pedal is not supplied anywhere.
Click to expand...
What I think I'll do is mount/bolt/attach everything up and see how it operates with the existing pedal pin.

I'm also thinking about using a spacer between the HB and firewall; 1/4" or 1/2".
 
CDA 455 II said:
Where'd you get that black plate?🤔

One or two of those would make a nice spacer(s).:grinpimp:
Click to expand...
I made the plate to move unit up to match the firewall on my 72 pickup. The lower 2 bolts are in line with the push rod. Not sure if your bronco matches a 99+ SD HB bolt pattern. Not hard to adapt. maybe you can just space with washers, or drive captive bolts out and use longer bolts.

Spacer length was cut so the rest position put pedal at stop, switch as-is. 72 Pedal is high, like it was but needs the whole throw to floor. pedal ratio is 5:1 as it had EOM power brakes.

One of the best mods. Brakes went from 'meh' to 'holy shit'. '94 12" rotors, rear drums, 40" tires
 
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HB increased assist so much that in addition to rear WW prop valve at max (-57%), I had to go 3 step down in rear drum brake cylinders (-65%). Otherwise rear would lock up. This is with rear fuel tank, heavy hitch bumper, 40" spare and tools in bed.

Given you haul a camper, you may not have same issues.
 
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