Hey Guys
I have a 1994 F350 that has a Vacuum brake booster. We are in the process of doing major rebuild to the truck. Master Cylinder is appearing to have been leaking so we are planning to replace the brake booster. But I know a hydroboost is a better system.
Have any of you converted your trucks?
Which one would you buy?
How did you plumb it into the power steering?

Thank you!!

 

I've converted both my '88 and '93 F250 to hydroboost. The '88 I think was a junkyard unit got off ebay and rebuilt, the '93 I found a rebuilt one on sale at some auto parts place, think it was an online sale? Both of these would be the stock unit used in the F-superduty/F-450. Later Superduty trucks use a different unit that would need modification to fit in our trucks, the bolt holes are different and hose setups possibly as well?

The '88 I swapped in a Saginaw power steering pump off a think a Lincoln (another ebay purchase). It came with a bracket that needed minor grinding to fit, but had an extra port for the return line from the hydroboost unit. The pressure line I needed to rebend, and I think cut the end off and flare? I probably used what would have been the stock hose for an F-superduty, which would have used the ford stock powersteering pump (C2? i can't remember what its called). The line from hydroboost to power steering was stock for F-superduty, and return line from the power steering cooler to the pump is just a rubber line. The pedal is different too, someone had a very good thread showing the differences! I believe the pushrod needs to be higher on the pedal? So I was able to grind off the weld, push out the metal cylinder it slips over, redrill in a new spot, press the cylinder back in and weld it all up. Later on the vacuum pump died so I removed it. Since the HVAC was mostly cable controlled, and the truck didn't have cruise control, so I don't think I lost any functionality? Truck has been mothballed for a couple years so I don't completely recall.

In the '93, with the serpentine belt, I couldn't figure out a way to easily fit a Saginaw pump (at least I couldn't find how anyone else did it...) So I bought a rebuilt Ford that had the extra nipple on the reservoir, pump needed replacing anyway... I think I was then able to use all stock lines from a F-superduty that are available over the counter. Same pedal mod would have happened. With some research, I was able to get a shorter serpentine belt, and after getting a new superduty electric vac pump, I removed the belt power one and used the shorter belt. Also pulled out most of the vac piping, just leaving where it goes into the HVAC controls. (cruise is controlled by electric servo on my '93)

Master cylinders may be slightly different? I remember grinding the mounting holes slightly bigger on at least the '88... don't recall if I had to repeat that on the '93. You may be able to use a F-Superduty master cylinder, but I don't know if that would screw something else up.
Good news is I saved a lot of receipts and part numbers I used, bad news is they are scattered in a mess in the garage....

A lot of what I used came from info I found on here, there are a couple good threads, especially the one about the pedals being slightly different.

 

Thank you Tecgod13!!
Great write up.

I just put a brand new Motocraft ps pump on. Sounds like I should went to one for a Superduty? I don’t think this one has any extra nipples.

What year did the Superduty go hydro…like 99?? They are a little more expensive!!

My cruise is also electric and I think only heat n ac are vac controlled.

Thanks again! I’ll look for the pedal swap.

 

F-Superduty as in the early F-450's, not the "Superduty" line of trucks thats around now. I don't know when they went hydro, but the F-Superduty was the heavy duty line, probably all cab and chassis trucks with heavier frames and axles. These were the trucks that may have had the driveline parking brake. Somewhere along the line, Ford decided that F-150's were just light duty trucks, and F-250's and F-350's as the heavy duty ones were called "Superduty's" (marketing...) At that point they would have branched out the F-450's, F-550's, etc as heavy duty commercial trucks.

Generally speaking, parts from the newer "Superduty" pickups will not fit our trucks.
You may be able to find a replacement 'reservoir' for the pump you just got with 2 return nipples. You may also be able to just T in both return lines, however some have reported that it constricts the return from the brake booster and causes issues. I don't know if that is true.

Good news is I happened upon some of the paperwork from the '93 swap just the other day in the garage. The hydroboost unit I got was from Autozone and happily only had a $5 core charge which made it quite affordable. Not sure if I have the part numbers for the hoses in the same pile, but I could look if you are interested.

 

Be sure to share what you find, please.

Roy

 

Here is a thread from OB on converting the peddle to Hydroboost.

https://www.oilburners.net/threads/h...t-pedal.89057/

How to swap to hydroboost swap from BlueOvalTrucks.com
https://www.blueovaltrucks.com/tech/hydroboost.htm

Another one from this Forum:
https://www.ford-trucks.com/forums/1...st-brakes.html

Charlie

 

I've done this to my '92; The results are fantastic even with drums on the back still! The pedal is always firm and doesn't fade hardly at all and when you hit the brakes, the truck will squat down and stop really nicely!