Mounting Hydroboost Over the Fender

[EricLar80]

I am wondering if anyone has moved and mounted the hydroboost/master cylinder assembly straight over the inner fender? Not using an angled bracket, or that eBay bracket that is straight but sets the assembly out. Mounted directly to the firewall.

I've seen that some people keep it in the same location as stock on the firewall, but that it is very close to the engine. I have a 351W block with EFI so I don't think there will be enough room to get to the headers and whatnot.

Here is the plan:

• Move the brake pedal assembly to the other side of the divider; between the divider and the column
• Remove pressed-in bushing on brake pedal by beating it with a BFH (done)
• Weld pedal to new, longer bushing that spans the section the clutch sits in
• Add a second lever arm to the bushing where the clutch pedal would be that has the pin to attach to the hydroboost
• Move master cylinder mounting hole over 5.25" towards driver and put hydroboost there

Looks to me like it will work, but it would be nice to know if anyone else has done this before.

Thanks!

 

[68ford]

My friend just did what your saying basically. He has an auto trans so the clutch was no longer used. He welded a couple pieces of metal and basically connected the clutch and brake pedal so they swing as one. Welded a pedal across both then drilled a hole for the master cylinder rod in the clutch pedal. Let him clear the stock intake off a 351 out of a early 90s lightning.

 

[EricLar80]

There you go - that sounds pretty close to what I am planning. Although that sounds a little easier if you already have a clutch pedal, but maybe not as clean. Would be great to see a picture if there was one floating around.

 

[68ford]

It just looks like a wide auto pedal until you see 2 vertical pieces on each end instead of in the center like a normal pedal. Where he welded them together is just below the steering column. You really don't see it.

 

[sanndmann3]

I basically did something similar. I moved the brake pedal to the clutch position. The arm is curved to wrap around the steering column. I flipped the pedal arm over so it wraps the other way. Then I cut the pedal off the arm and rotated it back to the correct position and welded it back together. I'll have to what pics I have if that would be helpful. I also have fuel injected 351 and this mod provides plenty of room for the hydro/master...

 

[EricLar80]

Yeah, I’d like to see it! Apparently the clutch pedal is exactly the same but bent the other way. Even has a hole to shove a pin into.

 

[rguest3]

EricLar80 - I have used the Inline Bracket you mentioned from eBay. Very easy and straight forward install. Plenty of room for Header and steering column access.

My 76 will be the 3rd 351W EFI motor install with this type of Booster Bracket.

No permanent modification or rigging of Bronco in the process.

 

[garberz]

There you go - that sounds pretty close to what I am planning. Although that sounds a little easier if you already have a clutch pedal, but maybe not as clean. Would be great to see a picture if there was one floating around.

Eric, I have a couple of clutch pedals, your welcome to come pick on up if you’d like.

Mark

 

[5001craig]

EricLar80 - I have used the Inline Bracket you mentioned from eBay. Very easy and straight forward install. Plenty of room for Header and steering column access.

My 76 will be the 3rd 351W EFI motor install with this type of Booster Bracket.

No permanent modification or rigging of Bronco in the process.

I've wondered if there are any cons to using the ebay over the fender bracket as I've had one on the shelf for a couple years. Will be going hydroboost.

Wanted to ask this question when I read this thread but the OP seems opposed to using the ebay bracket. Hope this isn't a thread hijack.

 

[EricLar80]

The over-the-fender ebay bracket looks like it will work fine, but I wanted to try something different to limit the under-hood clutter.

Mark - I appreciate the offer but I already went by the Rocky Roads shop in Chatsworth and found a 2nd brake pedal to modify. It's very convenient having two Early Bronco spare parts supplies 20 mins away...

I ordered a 4130 steel tube from McMaster that I will modify to weld the lever arms to. Should be here tomorrow and I am hoping to make some progress this week.

 

[Broncobowsher]

Remember to think of how much torque that junction between the two pedals will take when you have that oh crap moment and try to push the pedal through the floor. I've known people who have panicked enough that they actually bent a brake pedal on it's own. Much less a modified one. There is a lot of leverage up in that area and being in a seat you can generate a lot of force.

 

[68ford]

Remember to think of how much torque that junction between the two pedals will take when you have that oh crap moment and try to push the pedal through the floor. I've known people who have panicked enough that they actually bent a brake pedal on it's own. Much less a modified one. There is a lot of leverage up in that area and being in a seat you can generate a lot of force.

With your concern, I'd figure I'd show you a photo of my set up and scare you
https://waynesbronco.shutterfly.com/377

 

[nvrstuk]

I think my write up on this back in 2011 is someone on CB here... if not, you can see on my latest build that I moved the assembly appr another 4-5" farther to the left...

This is an OLD pic...probably 2011. Since then all the p/s stuff is gone, SEFI, fenders, no distributer, you name it BUT it gives you an idea where the m/c sits in relation to the valve cover when moved directly where the clutch swing arm would be.

If you'd like, check out the location of where it is now moved over another 5 inches to clear the ORI strut tower hoops.

Another idea we used was on a ZF install we of course needed to keep the clutch swing arm but extended the horizontal shaft, keyed it and mounted the HB/MC directly over the fender. Worked great.

 

[EricLar80]

Remember to think of how much torque that junction between the two pedals will take when you have that oh crap moment and try to push the pedal through the floor. I've known people who have panicked enough that they actually bent a brake pedal on it's own. Much less a modified one. There is a lot of leverage up in that area and being in a seat you can generate a lot of force.

I don’t think I have the force available to twist a 1/4” wall, 1 1/8” diameter, 4” long tube with my leg. Regardless, all 4 tires would lock given my setup if I were to do that, so I have to be careful when panic stopping anyways.

 

[68ford]

I don’t think I have the force available to twist a 1/4” wall, 1 1/8” diameter, 4” long tube with my leg. Regardless, all 4 tires would lock given my setup if I were to do that, so I have to be careful when panic stopping anyways.

Depending on the bore diameter of your master cylinder and what booster you have, you your engine does and you no longer have assist, you will likely be putting that tube and especially your welds to a series test.

 

[EricLar80]

Depending on the bore diameter of your master cylinder and what booster you have, you your engine does and you no longer have assist, you will likely be putting that tube and especially your welds to a series test.

Let's just put this in perspective - the brake pedal pin is 7/16" in diameter where it goes through the pedal arm, which means that it has a cross sectional area of .150 in^2, is in single shear, and it takes the full brunt of braking force.

If the weld made is .0938" (quite small) and goes around the full circumference on both sides of the shaft, then it would have an area of .588 in^2. So, almost 4x the cross-sectional size. That, and the joint is located twice as far out as the pins diameter, so we get double the strength there. Should be, at minimum, 7 or 8x as strong just using a back of the napkin calculation.

*Edit - the pin is actually 7/16" where it goes through the pedal arm*

 

[68ford]

Eric lar my response was more so a joke about how hard it is to stop hydro boosted vehicles if they loose assist. I also said it would be "tested" not that it might actually be a weak spot and fail.

 

[EricLar80]

The loading is definitely different than before, that's for sure.

 

[sanndmann3]

Yeah, I’d like to see it! Apparently the clutch pedal is exactly the same but bent the other way. Even has a hole to shove a pin into.

Here are some pics of my set up, sorry for the delay...
1st shot from engine bay... not sure where all the sand came from... %)
Good amount of clearance to the valve covers and upper intake.

Next 2 shots are of the brake pedal arm flipped over so it wraps around the column from thee other direction. Cut the foot portion off and rewelded it (with re-inforcements on both sides).

the pedal location appears stock, right where you would expect it when slamming on the brakes. Let me know if you need anything else.

 

[EricLar80]

Here are some pics of my set up, sorry for the delay...
1st shot from engine bay... not sure where all the sand came from... %)
Good amount of clearance to the valve covers and upper intake.

Next 2 shots are of the brake pedal arm flipped over so it wraps around the column from thee other direction. Cut the foot portion off and rewelded it (with re-inforcements on both sides).

the pedal location appears stock, right where you would expect it when slamming on the brakes. Let me know if you need anything else.

That looks great! Thanks for sharing.