F-Superduty Hydro Boost Parts

[towcat]

That's what I meant, that there ain't no special F-Superduty pedal cause linkage geometry works for both boosters. As for the lack of pedal effort issues with the '92-'97 F-Superduties, I have an idea why that is, but I can't confirm it cause I got not a single F-Superduty pedal to measure up - I'd like to know what's the distance between the pedal arm main pivot and the booster pushrod pin, as well as overall length of the pedal arm from its main pivot to the middle of the pad the driver steps on, for both '87-'91 and '92-'97 F-Superduty pedals.

By the way, what are your thoughts on that brake pedal Riotwarrior was given?

I have a '94 F450 getting salvaged out, so I can have a answer for you on the pivot to pin length in a couple of weeks.
As far as RW's welding work, I decline to get invoved in the critique. I've already spoken about welding work on the pedal arm in the past and that hasn't changed. In a nutshell, any welding on the pedal arm is a bad idea.

 

[LCAM-01XA]

Oh yah, take your sweet time with them measurements, I ain't in no rush whatsoever - who says you can't live on island time in the middle of the desert

As for the other topic of discussion, your line of thinking and my lack of proper F-Superduty pedal assembly was the reason why my booster ended up in its slightly odd position...

 

[gonecrazyi]

Ill also add I used my stock master cylinder instead if the bigger f superduty one.

 

[riotwarrior]

No it ain't - matter of fact I think this is the worst way one can go about making one pedal out of two. Reason - the butt weld! Just measured up my small truck, the distance between the center of the pad you step on and the center of the pin for the booster pushrod is right around 11", on the pics of the modded pedal it looks like the weld is about and inch away from the booster pushrod pin. During brake application the booster pushrod pin becomes a pivot support and this particular pedal becomes a cantilever with ratios of 1:11 (I'm well aware this ain't exactly scientific, tis just an approximation cause I don't seem to be able to find my speadsheet that can calculate everything properly a whole lot faster than my half-dead brain will) - last time I actually measured it I was able to put down about 170-175 lbs of pedal force during panic stop, which with our cantilever becomes around 1900 lbs shear force at a weld that is what, 1-3/8" wide wide and 3/8" thick. To put it bluntly, even if both pedal pieces were properly chamfered/bevelled to ensure good penetration, this is still a sh*tload of force to recon with... IMHO the person who built this pedal is a moron, and should have that contraption they created shoved up their ass as deep as it will go!

Riotwarrior, I'm sorry if I come out as an a-hole, but I call it how I see it - and what I see there is something very very unsafe! It ain't irreparable tho - if the geometry of this particular pedal works out for your hydro setup then I suggest that you take it in for fish-plating ASAP - in other words it needs a reinforcement plate welded to the passenger-side of the pedal arm from right around the main pivot at the top to several inches below the booster pushrod pin. Given the width and thickness of the pedal arm in that area, I'm thinking a piece of flat-stock that is 1" wide and at least 1/4" thick should work out pretty good for such reinforcement as it will allow for fillet welds on the long edges so there will be good penetration in both pieces being welded. Also, you may wanna take it to a different welder guy - see, the customer may always be right but often they're also uneducated (not an insult directed at you, just a general statement), and it's up to the fabricator to suggest modifications to the project at hand so the end result is still what the customer wants, but it also serves its intended purpose right - that welder guy you used forgot the last part of this, for what he gave you is what you wanted (two pedals made into one) but it's not what you should run as a major part of your vehicle's safety equipment.

I do appreciate your concern, truly I do, I have absolute faith in this weld, it was done NOT by me but a gentleman whom has more years welding doing hi pressure gas line and pipeline welding and so forth than I have years on this earth! He is truly a master welder. If I had even the remotest concern on how he welded it, I would have not mounted it.

If I sense any issues, I'll definitely look at other options.

Please understand that I have very powerful legs and have broken the aluminum mounting bracket for the pedals previously....but not once has any brake arm bent even slightly....

If that arm was used 90 degrees to it's intended purpose I would fishplate it. However, since your pressing through a 1" thick piece of metal, then I doubt I can break it.

Again thanks, if I sens an issue I'll be on it like fat kids on smarties....

 

[bike-maker]

I changed out my plastic bushing when it wore out due to the hideous pedal pressure of the stock clutch with a bronze equivalent.

Where did you source the bronze bushings? You have to make them?

I finally got around to measuring the pushrod for the master cylinder, see pic below.
And your more than welcome to come down and take a look see for yourself.

I went back to the JY this morning and robbed the brake pedal off of the same truck.
As near as I can tell (hard to measure with one of the brake pedals still in the truck), the brake pedal off of the F-Superduty has the pin located about 3/4" up higher than the standard F-series pedal. That is quite the difference.

 

[riotwarrior]

Where did you source the bronze bushings? You have to make them?

I finally got around to measuring the pushrod for the master cylinder, see pic below.
And your more than welcome to come down and take a look see for yourself.

I went back to the JY this morning and robbed the brake pedal off of the same truck.
As near as I can tell (hard to measure with one of the brake pedals still in the truck), the brake pedal off of the F-Superduty has the pin located about 3/4" up higher than the standard F-series pedal. That is quite the difference.

Need I say more?

 

[FORDF250HDXLT]

That's what I meant, that there ain't no special F-Superduty pedal cause linkage geometry works for both boosters. As for the lack of pedal effort issues with the '92-'97 F-Superduties, I have an idea why that is, but I can't confirm it cause I got not a single F-Superduty pedal to measure up - I'd like to know what's the distance between the pedal arm main pivot and the booster pushrod pin, as well as overall length of the pedal arm from its main pivot to the middle of the pad the driver steps on, for both '87-'91 and '92-'97 F-Superduty pedals.

By the way, what are your thoughts on that brake pedal Riotwarrior was given?

I have a '94 F450 getting salvaged out, so I can have a answer for you on the pivot to pin length in a couple of weeks.
As far as RW's welding work, I decline to get invoved in the critique. I've already spoken about welding work on the pedal arm in the past and that hasn't changed. In a nutshell, any welding on the pedal arm is a bad idea.

has it been a couple weeks yet?
just a reminder.not rushing.

the OBS truck uses a completely different pedal geometry compared to the 80-91 trucks. They are able to accommodate the vac booster and hydro units with one pedal assy. f450's definitely did exist from 92-97 and there has been no report of unusual pedal effort in order to get the trucks to stop.

i thought it was just me.but i recently read a thread on FTE in the 94-97 PSD section where another shared the same results.she's a firm pedal for sure.it's so much so,that after working i feel the desire to use both feet on the brake pedal to get any sort of comfort level.before work,it's aggravating,but once tired after working its bordering on miserable lol.

here it is.i feel exactly 100% the same way he does about the mod:
(member: wildstang)
http://www.ford-trucks.com/forums/1118094-hydroboost-brake-pressure.html

also,my father has an '08 6.4l psd f350 which has hydro.stepping on his brake pedal is like 3 times easier.i used it again a month or so ago after i swapped to compare.oh man i wish i had half the comfort level of that trucks brakes.not even close to the same.

i should add,i have my RABS bypassed with brake line.perhaps that is a no no with hydro and explains the issue?
i don't care for abs,so if this is my issue for some reason,id add a proportioning valve instead.perhaps the rear are doing most of the work right now and trying to use drum brakes mostly is causing so much extra firmness.hmmm.this makes sense as his truck has disc all the way around.maybe im finally thinking it all out correctly.......

 

[bike-maker]

Got the hydroboost all installed yesterday.
A few tidbits of info I learned;

Laying the two brake pedals next to each other on the floor and taking accurate measurements confirms the 3/4" difference in pin height.

The plastic bracket that hooks to the brake arm to actuate the vacuum switch for the cruise control must be different for the sup duty brake pedal; there's no way the original will work on the new pedal. The truck I robbed the hydroboosat from didn't have cruise control. A simple bracket could be made up to correct this, but just concreted my decision to ditch all the cruise control stuff on my truck as I've never used it anyway.

The reason for the different pin location is the hydroboost booster's actuator rod comes through the firewall perpendicular; the stock vacuum booster has it angled down pretty good - you can see it in the pic below.

I was able to get the pedal assembly out of the bricknose superduty by just loostenng the steering column and laying the steering wheel down on the seat, then rolling the pedal assembly around the steering column. Getting the pedal assembly out of my 84 required removing the steering column.

I used the stock cast iron master cylinder; it bolted right to the hydroboost booster.

The brakes definitely work better now. It's not a case of accidentaly locking the brakes up like I've heard; it still takes about the same amount of pressure to make the average stop, but you only have to push the brake pedal down about 1", where I would probably push the pedal down almost 3" with the old vacuum setup, and the feel on the brake pedal is much more consistent. The true test will be when I hook the 5er up to the truck and have to make a panic stop.

 

[FORDF250HDXLT]

Mike, could you please include the year(s),auto or manual part(s) and truck(s) your working with?
i also lost cruise after this mod and didn't understand why (but because i hardly use it,i couldn't directly relate it to this mod,so was unsure.)

 

[bike-maker]

My cruise control hasn't worked since my truck was a gasser.
When I swapped to diesel, I had an entire 89 F250 donor truck. So I have an 89 ZF5, 89 manual tilt steering column, and a pedal assembly out of a 86 F150. The hydroboost parts were taken from a 1990 F-Superduty.
To disengage the cruise, I know the 80-91 use a vacuum switch on the brake pedal, the 92-97 trucks might use a pressure switch on the brake master cylinder, which could be disabling the cruise control on your truck. Somebody else more familiar with the 92-97 trucks will have to chime in here.
1 more complication for me was that I over rode the neutral safety switch when I switched from the C6 to the ZF5; the same wiring on a manual equipped truck would have gone to the switch on the clutch, resulting in having to depress the clutch to start the engine. So my electronics think that the trans is in neutral/park(auto) or the clutch pedal is depressed(manual) all the time, which would disable the cruise control as well.

 

[ADV]

So I am taking the hydro boost off of my 88 fsuperduty and putting it on my new to me 93 f350. I am a little confused to witch master cylinder is better I have both so can use either one. Any one need the brake pedal from a 88 SD?

 

[towcat]

So I am taking the hydro boost off of my 88 fsuperduty and putting it on my new to me 93 f350. I am a little confused to witch master cylinder is better I have both so can use either one. Any one need the brake pedal from a 88 SD?

i went ahead and used the F450 master on my F350. no line mods necessary.
as far as the hydro brake pedal, post an ad over in the marketplace and specify if it is a auto or manual trans brake pedal. It's a sure bet the pedal will be gone in under a day if you price it reasonably right.

 

[eatont9999]

It will really suck if I lose cruise control to go to hydroboost. Also, my F450 pedal looks to be from a manual trans truck. Has anyone been able to get around the CC switch problem?

 

[towcat]

It will really suck if I lose cruise control to go to hydroboost. Also, my F450 pedal looks to be from a manual trans truck. Has anyone been able to get around the CC switch problem?

I did. All you need to do is trim down where the pedal stud goes around the plastic and glue the cancel block down. It's not mission critical and there is some adjustment for it too. I thought I had a pic of the after, but all I can find is the "before" shot. The pedal on top is the pre-hydro arm and the bottom one is the hydro arm. Mark the location on the hydro arm, trim the plastic block and glue it down. done!
The arms are also auto trans arms too.

 

[eatont9999]

If you get a chance, could you snap a picture of the after? I think I have a mental picture but not sure.