gnxtc2
Active member
Ever since of doing the hydroboost conversion from the vacuum booster, I was never happy with the brake pedal resting height. Some complained that the brake pedal was high. You couldn't pivot your right foot from the throttle to the brake pedal. You had to physically lift your foot and press the brake pedal. This extended my brake reaction time.
Background.....and what my conversion consisted of.
I originally used the OBS F-SD set up (hydroboost and master). Before anyone knew that the F-SD trucks had a different pedal, the common thing to do was rotate the brake rod 180*. What this did, was put the rod at an extreme angle and the pedal was hard. The F-SD trucks had rear discs which is the reason the master cylinder had a larger bore and reservoir. At the time I was running the rear disc conversion using the 70s Eldorado caliper. Wasn't too happy with that conversion. Never liked the brake pedal feel.
www.powerstrokearmy.com
So I got rid of the rear discs and went back to the OEM drum brakes. At the same time, I also replaced the proportioning valve on the master that matched for the drum brakes. If I panic stopped, the rear wheels would lock up. This is not good. Still not happy with the pedal feel, it was hard. Keep in mind of the high brake pedal.
Then the F-SD pedal came to light. I modded the stock pedal by moving the brake pin. Pedal got softer/felt better due to alignment of the brake pod was in line with the hydroboost unit. The rear wheels still were locking up. Did some research, and the F-SD master was too big for the drum brakes. This when Peroni found out that you can use the hydroboost unit from the F-53 chassis.
www.powerstrokenation.com
The F-53 hydroboost unit fits the firewall of the OBS trucks with no mods and the OEM master bolts right on. So I converted to the F-53 hydroboost unit with the OEM master. Braking was awesome. Pedal feel was great, etc, etc. But the brake pedal was still too high for my liking.
Then the power steering pump mod came out. You needed to source a vacuum pump, P/S pump, AC compressor bracket from a 7.3 E-series van. Also, you needed the P/S pump pulley from the E-Series. The P/S pump was the four bolt pump that is used on the later model Ford vehicles. A few custom hoses utilizing the -6an fittings this mod was done. No more pump whine, no more steering bind when your foot was on the brake; the later model pump put out more pressure and volume.
www.powerstrokearmy.com
When I drove my truck, I still didn't like the height of the pedal. It bothered me driving. From the floor to the top of the pedal, I got 6 3/4". A stock truck with a vacuum booster measured 5 9/16" My 2016 F-350 came in at 5 1/2". Clearly my pedal was approximately ~1 1/4" too high. So I started looking into how I can lower the pedal. My options:
- Make a spacer to fit between the hydroboost unit and firewall (too much work)
- Cut and reweld brake rod (If I have to replace the unit, then I have to mod the rod. Not practical)
- Move pin on brake pedal closer to the driver. (This is what choose)******
So I removed the brake rod, removed the brake pin, install the pedal, held the pedal around 5 1/4"- 5 1/8" from the floor and marked the brake rod. The mark was approximately 3/8" toward the driver. The hole needed to be milled since it was partially into the existing hole. Welded the pin in the new location and the brake pedal is approximately 5 1/4" from the floor. I now can pivot my foot from the throttle to the brake. I pressed down on the pedal and it was no where near close to the floor.
The plug is the OEM location for the vacuum booster. I popped out the pin. You can see the scribe mark for the new location.
![20240728_114938[1].jpg](https://powerstrokearmy.com/attachments/20240728_114938-1-jpg.187559/ "20240728_114938[1].jpg")
Sorry I didn't get a pic of the new pin location. But here is the pin re-installed and welded in place. I didn't fill in the hole in case I have to slide the pin. Most likely it's going to stay like this.
![20240731_130957[1].jpg](https://powerstrokearmy.com/attachments/20240731_130957-1-jpg.187558/ "20240731_130957[1].jpg")
Hope this helps.
Billy T.
[email protected]
Background.....and what my conversion consisted of.
I originally used the OBS F-SD set up (hydroboost and master). Before anyone knew that the F-SD trucks had a different pedal, the common thing to do was rotate the brake rod 180*. What this did, was put the rod at an extreme angle and the pedal was hard. The F-SD trucks had rear discs which is the reason the master cylinder had a larger bore and reservoir. At the time I was running the rear disc conversion using the 70s Eldorado caliper. Wasn't too happy with that conversion. Never liked the brake pedal feel.
Hydroboost Conversion Done
I never did like the feel of the vacuum boosted brake system. After adding custom rear disc brakes I thought a hydroboost conversion would compliment my upgraded braking system. I used parts for a 97 F Superduty and they are a 100% bolt in deal. Here is my parts pile. Everything is brand...
www.powerstrokearmy.com
So I got rid of the rear discs and went back to the OEM drum brakes. At the same time, I also replaced the proportioning valve on the master that matched for the drum brakes. If I panic stopped, the rear wheels would lock up. This is not good. Still not happy with the pedal feel, it was hard. Keep in mind of the high brake pedal.
Then the F-SD pedal came to light. I modded the stock pedal by moving the brake pin. Pedal got softer/felt better due to alignment of the brake pod was in line with the hydroboost unit. The rear wheels still were locking up. Did some research, and the F-SD master was too big for the drum brakes. This when Peroni found out that you can use the hydroboost unit from the F-53 chassis.
Converted the vacuum brake pedal into hydroboost pedal
The F-53 hydroboost unit fits the firewall of the OBS trucks with no mods and the OEM master bolts right on. So I converted to the F-53 hydroboost unit with the OEM master. Braking was awesome. Pedal feel was great, etc, etc. But the brake pedal was still too high for my liking.
Then the power steering pump mod came out. You needed to source a vacuum pump, P/S pump, AC compressor bracket from a 7.3 E-series van. Also, you needed the P/S pump pulley from the E-Series. The P/S pump was the four bolt pump that is used on the later model Ford vehicles. A few custom hoses utilizing the -6an fittings this mod was done. No more pump whine, no more steering bind when your foot was on the brake; the later model pump put out more pressure and volume.
Upgraded Power Steering Pump Installed
I can't take credit for coming up with this mod. In my search I found discussions going back to at least 2004 about replacing the stock C2 pump with a C3 pump using all Ford parts. Any OBS owner knows the stock C2 is lacking in both flow and pressure and that most "re-manufactured" pumps...
www.powerstrokearmy.com
When I drove my truck, I still didn't like the height of the pedal. It bothered me driving. From the floor to the top of the pedal, I got 6 3/4". A stock truck with a vacuum booster measured 5 9/16" My 2016 F-350 came in at 5 1/2". Clearly my pedal was approximately ~1 1/4" too high. So I started looking into how I can lower the pedal. My options:
- Make a spacer to fit between the hydroboost unit and firewall (too much work)
- Cut and reweld brake rod (If I have to replace the unit, then I have to mod the rod. Not practical)
- Move pin on brake pedal closer to the driver. (This is what choose)******
So I removed the brake rod, removed the brake pin, install the pedal, held the pedal around 5 1/4"- 5 1/8" from the floor and marked the brake rod. The mark was approximately 3/8" toward the driver. The hole needed to be milled since it was partially into the existing hole. Welded the pin in the new location and the brake pedal is approximately 5 1/4" from the floor. I now can pivot my foot from the throttle to the brake. I pressed down on the pedal and it was no where near close to the floor.
The plug is the OEM location for the vacuum booster. I popped out the pin. You can see the scribe mark for the new location.
Sorry I didn't get a pic of the new pin location. But here is the pin re-installed and welded in place. I didn't fill in the hole in case I have to slide the pin. Most likely it's going to stay like this.
Hope this helps.
Billy T.
[email protected]
