Econoline Hydroboost Conversion How-To

Big_ern_101

Senior Member
Joined
Mar 19, 2023
Posts
364
Swapping from a vacuum actuated booster to a hydroboost gives several advantages - more assist, and on the diesel eliminates the failure prone vaccum pump from supplying braking assist.

First, gather the parts. This parts list was to do a swap in a 2006 6.0 Diesel Econoline. Your application may be different.

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Note the following: I sourced most items as NOS from Ebay searcing both the part numbers AND the alternate part numbers. I did not use any aftermarket components. The booster hard return line 4C2Z-3A713-A is the only part I ran into that was complete NLA, no aftermarket. Ford Parts Giant and Taska both cancelled my order after I placed it. Found one on Ebay. This part typically comes with your booster if you buy it used, so that may be what you need to do.

Also note: 8C2Z-2A051-AB is the line support bracket that comes off the master. The interchange says not compatible with 06 and the correct part number is NLA. This part works just fine, not sure why it is listed as not compatible.

Also note: The pedal assembly is the same part number for E-350 Vacuum Brakes and E-450 Hydroboost in 06. Your mileage may vary. All the brake switches and bushings were a direct swap.

Also note: The power steering cooler is the same part number for vacuum boost and hydroboost brakes. I did not change my power steering cooler.

Now on to the meat and potatos.

  • Drain the fluid from the power steering reservoir and remove it.
  • Remove cold side intercooler piping, intake, air cleaner, air cleaner box.
  • Disconnect degas bottle and flop it into where the airbox used to be.
  • Disconnect the fluid return line from the pump between the pump and the reservoir
  • Disconnect the pump discharge from both the pump and the steering gear.
  • Remove fluid from master cylinder
  • Disconnect electrical and brakelines from master
  • Remove master from booster.
  • Disconnect vacuum line from booster, cap it on the distribution manifold (more on this later)
  • Disconnect booster from pedal, remove booster. Its held on by the 4 bolts/studs inside the cabinet around the brake pedal.
  • Assemble your new hydroboost brake setup. Booster, master, all hard lines, hard line brackets.
  • Install hydroboost assy in vehicle. Reconnect master to pedal
  • Bench bleed master, connect brake lines (they need to be swapped front-to-back, but can be flexed as required)
  • Connect electrical to master, plugs are the same and harness reaches no problem.
  • Connect new power steering fluid lines.
  • Top port on booster connects to steering gear.
  • Middle port is a barbed fitting and is return to reservoir.
  • Bottom port on master connects to power steering pump.
  • Connect line from hydroboost to pump.
  • Install new return hose, connect to return connection from hydroboost.
  • Bleed your brakes. I used two 32oz bottles of brake fluid and I am still a little short. I bled my brakes a lot though, the old fluid was pretty dark. I barely had any air, mainly on the rears.
  • Install all the intake piping and the degas bottle
  • Install hydraulic reservoir, fill with fluid. I needed 2 quarts total, give or take, to fill up the system.
  • Jack the front wheels up, run the steering wheel back and forth a bit to bleed air from the system.
  • Start the vehicle and go for a drive, your brakes should have a great pedal and excellent assist.
  • Check the level after a bit of driving to make sure all the air is out.

Couple notes. Should I have used braided line instead of OEM? Maybe. The routing could have been nicer. I wanted to get this done in a weekend and have a 200k+mile OEM style lines, so I went with OEM.

Eliminate the belt driven vacuum pump? I hooked up a Dorman F250 electronic vacuum pump, but I must have a slight leak as it never stopped running so I went back to my belt driven pump. For the short term, I am going to keep the OEM vacuum pump for the HVAC controls and maybe get into it further this winter.
 
Last edited:
Great info there.

I was afraid of the catastrophic vacuum pump failure but wasn't up for the DIY effort. I opted to have ABS Power Brake Inc. (Orange CA. www.abspowerbrake.com) do the vacuum to Hydroboost conversion on my 2005 SMB. They've done many of them and I would recommend them based on my experience. It's certainly nice to have that worry off the table. And I have no affiliation w/ ABS other than being a satisfied customer.

Cheers
 

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