F-Superduty Hydro Boost Parts

[sle2115]

I need to step in a clear this up.
there is a need for the proper brake pedal for installing hydro on the 80-91 trucks. on the 92-97 trucks, there is no part number difference between the hydro and non-hydro brakes. therefore, the non-hydro brake pedal will will work on the 92-97 hydro swaps.

Sig shows 84, but does that apply to auto as well as manual transmission? I wasn't sure never having dealt with an auto truck and hydroboost.

 

[FORDF250HDXLT]

on the 92-97 trucks, there is no part number difference between the hydro and non-hydro brakes.

thanks!
im gunna try the F-superduty master i think.
hard brake pedal.though way better than when i first installed.kills me after working lol.

 

[riotwarrior]

I need to step in a clear this up.
there is a need for the proper brake pedal for installing hydro on the 80-91 trucks. on the 92-97 trucks, there is no part number difference between the hydro and non-hydro brakes. therefore, the non-hydro brake pedal will will work on the 92-97 hydro swaps.

I am not saying that the pedal of a non hydro boosted truck won't work for a hydro conversion, I am however saying that the hydro trucks pedal should be transfered as the pushrod pin is in a higher location on the pedal arm. This equates to a different value of torque applied to the MC.

I have measured and compared the difference and it is enough that seeing as the system has It I suspect it was designed with it in mind thus I use it.

 

[lotzagoodstuff]

make sure the pushrod between the hydro and the master doesn't get lost.

Calvin, do you know if that pushrod is the same on a bricknose as it is on a 92-97? I have everything else to do the swap (bought it all brand new) but I can't install it because I need the pushrod.

BikeMaker: I am local in Vancouver and if possible I'd like to look at the pushrod as I've been thinking about making a bunch of them on a lathe as it's the only part you can't buy brand new.

Nice score for $75

 

[bike-maker]

I robbed all of the parts off of the F-SuperDuty this morning.

I'm going to try running my current master cylinder. When my vacuum booster went out I researched running the newer bricknose master cylinder in place of my cast iron one because I had the parts laying in my garage; the front and rear brake lines are reversed going into the newer master cyliner, and the fittings aren't the same size. The older ones appear to use a standard flared fitting, the newer ones are some kind of metric thread. The newer ones also incorporate the proportioning valve into the MC where the brake line connects to it; mine is separate and located down on the fame rail - same place as the RWAB valve is on the newer trucks. Needless to say, I opted to oblong the wholes on the cast iron MC and bolt it on the vacuun booster out of the bricknose.

The donor truck I got my parts from was a ZF5 truck, and so is mine; I'm going to do some measuring as to the location where the stud on the brake pedal is.

Towcat; you stated the hydro brake pedal is needed for the 87-91 trucks, but what about the 83-86?

Lotzagoodstuff; I'll take the rod out tomorrow and check it out, if I can just measure it with my calipers, it could save the hassle of having to drive down here.

 

[riotwarrior]

Ok so I flipped my vacuum booster off the Bronco today, and installed the hydro boost and while at it I swapped pedals.

Here are a couple of pics of the pedals
Top arm is the one I had modified with the SD pedal with the pin in the correct location for a hydro, the bottom one is the old vacuum booster pedal arm...lower pin location in relation to the pivot point where the pedal is hung.

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Booster mounted lines and such hung loose as I'll be getting new "O" rings for them.

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Almost got that damn thing ready to fire...

 

[lotzagoodstuff]

Nice pedal mod

I know you've already got it swapped in, but I changed out my plastic bushing when it wore out due to the hideous pedal pressure of the stock clutch with a bronze equivalent. Easy mod and I have a feeling the bronze bushing along with my feather light replacement clutch should keep me from ever having to touch it again.

Nice work, hydro looks like it was born there on the firewall!

 

[snicklas]

I have to agree with the benefits of hydroboost...

I drove E-2 (91 F-350 7.3 E4OD 2wd CC DRW) with the standard vacuum boost brakes. In the low speed, empty driving I did with it, I was very unhappy with the performance of the brakes.

My truck, (03 Excursion 6.0PSD 4wd 5R110) and it, along with all the 99+ SuperDuty Diesels have factory hydroboost and 4 wheel disk brakes. With my truck ~8000 it will stop very well. Empty, or towing, I have never been worried about having enough brakes. I towed my TT ~5000 home right after I got the truck (was setting up the hitch, brakes, etc) and the Ex and TT stopped better with just the truck brakes than my Durango with working trailer brakes.

In a panic stop, I am fairly sure the Ex stops better than my 98 Sable Wagon with 4 wheel disk and vacuum brakes. If I could put hydro on the car, I would!!!!

 

[gonecrazyi]

The pedal effort with the correct bracket is highly noticeable. The pedal was hard as a rock and took a lot if effort to push. It stopped great but with way to much effort. I swapped the correct bracket in and ut fixed my worn out clutch pedal and I can know rest my foot in the pedal and stop quick. One jab and i can lock all four 38s like their donut tires.

 

[FORDF250HDXLT]

I can know rest my foot in the pedal and stop quick..

wowah!!! im not even close to having this kind of comfort level.

 

[LCAM-01XA]

Nice pedal mod

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.

 

[LCAM-01XA]

wowah!!! im not even close to having this kind of comfort level.

And if you swap in an F-Superduty master cylinder you'll be even further away from it. The F-superduty has bore of 1-5/16", your factory one is likely 1-1/8". By increasing master cylinder bore you lose mechanical advantage in the hydraulic system, meaning you'll have to push on the pedal harder to make it build up the same line pressure. In bricknose trucks like the one Riotwarrior is working on this effect is negated by placing the booster pushrod pin closer to the pedal arm's main pivot, which also explains why Gonecrazy's unconfortably-high pedal force went away with the proper F-Superduty pedal (there was probably a linkage binding issue with his factory pedal as well). However, as per Towcat's info there is no such pedal for your truck, likely cause linkage don't bind no more. You could have one made like Riotwarrior did, by moving the booster pushrod pin higher on the pedal arm you will increase your leverage and thus you won't have to step on the pedal as hard, but you will also end up with more pedal travel (which may be a good thing if you currently feel pedal is too high when you brake). The moment you add the F-superduty master to this pedal tho, you're back to square one. Well, and possibly with linkage issues.

FWIW my bricknose truck still uses the factory pedal, I went around the linkage binding issue by simply angling the booster down some more. No change in pedal geometry means no need to change master cylinder to the F-Superduty monster to compensate for longer travel and softer pedal cause those simply ain't there. I actually did up the master bore a bit, went from 1-1/8" to 1-1/4" (Chevy 1-ton SRW setup IIRC), but only because I wanted I wanted a bit higher and stiffer pedal and felt the loss of mechanical advantage in the system will be fairly negligible - it did work out just like I planned it, but definitely not the direction you should be heading in if your current pedal feel is too stiff/high.

 

[towcat]

Towcat; you stated the hydro brake pedal is needed for the 87-91 trucks, but what about the 83-86?

I stated the pedal is needed for the 80-91 trucks. 83-86 would definitely be included.

 

[towcat]

And if you swap in an F-Superduty master cylinder you'll be even further away from it. The F-superduty has bore of 1-5/16", your factory one is likely 1-1/8". By increasing master cylinder bore you lose mechanical advantage in the hydraulic system, meaning you'll have to push on the pedal harder to make it build up the same line pressure. In bricknose trucks like the one Riotwarrior is working on this effect is negated by placing the booster pushrod pin closer to the pedal arm's main pivot, which also explains why Gonecrazy's unconfortably-high pedal force went away with the proper F-Superduty pedal (there was probably a linkage binding issue with his factory pedal as well). However, as per Towcat's info there is no such pedal for your truck, likely cause linkage don't bind no more. You could have one made like Riotwarrior did, by moving the booster pushrod pin higher on the pedal arm you will increase your leverage and thus you won't have to step on the pedal as hard, but you will also end up with more pedal travel (which may be a good thing if you currently feel pedal is too high when you brake). The moment you add the F-superduty master to this pedal tho, you're back to square one. Well, and possibly with linkage issues.

FWIW my bricknose truck still uses the factory pedal, I went around the linkage binding issue by simply angling the booster down some more. No change in pedal geometry means no need to change master cylinder to the F-Superduty monster to compensate for longer travel and softer pedal cause those simply ain't there. I actually did up the master bore a bit, went from 1-1/8" to 1-1/4" (Chevy 1-ton SRW setup IIRC), but only because I wanted I wanted a bit higher and stiffer pedal and felt the loss of mechanical advantage in the system will be fairly negligible - it did work out just like I planned it, but definitely not the direction you should be heading in if your current pedal feel is too stiff/high.

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.

 

[LCAM-01XA]

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?