Converting to hydroboost brake system

[Jakey]

1996 E-Superduty was available with Hydroboost, it had 1 5/16 Bore Master.
They are rather rare though and parts listings are wrong since they usually list the F450 88-97 booster. The one I have come across in the yard had hoses that were repaired with Gates "Flareless" repair kit, thus probably due to unobtainable replacements.

There is a slight difference in the bolt pattern at the firewall between 1992-1996 and 1997+ models.
The Ford 1 5/16" MC's used with hydroboost all appear to have a 3.4" bolt spacing.
Typical Ford MC bolt spacing is 3.2"
You may be able to get just the reservoir with the second inlet.
Also on the 1997+ E-series that I have seen with hydroboost, the return lines had a Tee-fitting in lieu of a second reservoir inlet.
Some of the Tempos and possibly Escorts had a CII pump with a remote reservoir housing.

My van is a 1996 E250 and I converted it to 4x4 about 4 years ago with 1999 F350 Superduty Axles(Dana 50 and 10.5)
Originally I made some parts to run the proper Master cylinder(1 3/8" Bore with 3.2" Bolt spacing) for that truck application with the van's original Vacuum booster.
About 3 years ago I got a hydroboost from a 1999-2004 Superduty and made a custom bracket and approx 1" spacer to run the hydroboost in anticipation of running a diesel engine. The spacer was made so that I could machine it down to make the pedal height correct without cutting the pedal rod on the booster. For the PS pump, mine had a Saginaw pump with integral reservoir. I replaced it with a remote reservoir unit.
Originally I thought I'd be able to use some OE hoses, but this just wasn't going to work and turned out to be a waste of money.

I think the long and short of it is you will have to do some custom fabbing

 

[etbadger]

Most modern hydroboost system have an accumulator (pressure reservoir) for braking after loosing the input pressure. We have lost engine & belt on our van with vacuum brake boost and it gave only about 1.5 brake presses to deplete. Measuring with the hydroboost unit we have gave about 4 presses (each one lower) before boost was gone.

It is also possible to increase the hydroboost accumulator volume for more backup, as it is just a hydraulic reservoir. Machine a disk to the dimensions of the stock accumulator and send a high-pressure hose off to a larger hydraulic accumulator at appropriate pressure pre-charge.

-e

 

[toddz69]

Weighing the options the vacuum brake reservior seemed to be the safer one incase of a catastrofic failure. If you lost a belt causing both steering and vacuum pump to fail the reservior holds enough for 2 or 3 pumps b4 the vacuum is depleted. But loose powersteering and hydro boost, i hope you have some good strength in your legs.

I'd say the hydroboost is actually better in case of catastrophic failure because the system reverts to manual brakes after you deplete the reserves in the accumulator. Once the reserve is gone from your vacuum booster, the brake pedal is hard as rock and it's difficult to exert enough pedal force to safely stop the vehicle.

Todd Z.

 

[toddz69]

Originally I thought I'd be able to use some OE hoses, but this just wasn't going to work and turned out to be a waste of money.

I think the long and short of it is you will have to do some custom fabbing

X2 on the hoses. Since my hydroboost experience has mainly been in the arena of retrofitting boosters into vehicles that didn't originally have them, I'm a big fan of making your own hoses using re-useable hose fittings. It's actually kind of fun to make them with the lengths/end clocking you want for that super-sano fit. If you're worried about replacement in the field, carry a length of hose long enough for your longest run along with the proper wrenches and you're set. I employ the same philosophy with brake lines on my Bronco - I carry several spare braided -3 AN lines as long as my longest run so I have a spare that will fit anywhere in the system.

Todd Z.

 

[carcrafter22]

Great info guys, keep it coming.

I am also a big fan of hydroboost and think its safer than vacuum. I use hydraulic steel braided hose rated for roughly 3500psi. I've never seen this hose have any issues unless it was constantly rubbing against something metal and even then it took a long time to cause any damage. From the sounds of it I may have to just suck it up and mod the firewall a bit to make the 98 E450 hydroboost work (no big deal once its done if it will be a future bolt in deal). I just dont want to have to take an F350 unit and cut/reweld the rod cause thats not really a feasable replacement if your hours from home and happen to get one from the local autoparts store in the middle of nowhere.

As suggested earlier I think I will just make my own hoses like I always have. I already have several sets of the proper fittings to screw into the hydroboost and convert the outlets to -6AN fittings.

Again, this is great info everyone love to hear anything else you have to say.

 

[Jakey]

I think that's your best bet, being able to get a replacement off the shelf hydroboost. I seem to remember the pedal rod length matching between the different years.
Also, for the master cylinder, assuming you have speed control. Check that the SCDS is located so it won't cause interference, as a side note 88-97 F450 Master fits too. It can also be plumbed into a 3/8-24 brake line tee if you decide to run a non cruise MC. Ford did this on the first trucks with electronic Speed Control Servos. These can be found on the frame rail of 1994 Vans and Pickups just ahead of the RABS valve.

For mine, I used hydraulic hose with JIC fittings since they work with the AN adapters.
Basically, AN fittings interchange with JIC fittings, but the AN's have tighter tolerances on the thread form(like having a radius spec for the root)
For mine, 1 hose needed 2 90's, and the other, one 90 and one 45, I had both made with a 90 and a straight and used 45 and 90 adapters with the straight ends. This has the benefit of being able to clock the fittings for best fitment, unlike a hose that is made with 2 angled fittings where it's permanent.

 

[nely]

Well it seems you have the info needed. When is this bad boy gonna show up in your build thread? I love the ambos and follow the threads.

 

[carcrafter22]

I'm in north dakota for the next 2weeks then I will be home to start swapping parts. I will make sure to post part numbers and pics of the install.I really appreciate all the help from everyone. I've already started ordering parts so they are home when I arrive.

I'm still unclear on the different master cylinders. I do have ABS and cruise control (cruise control isnt working tright now for some reason) I assume it matters what master I use? I was just gonna order the 98 E450 master with the hydroboost, sound good or should I just order a new replacement for my 96 e350?

 

[etbadger]

Cruise control masters have an additional outlet port on them for a backup emergency sensor to disable cruise control when brake pressure builds. There is already input to disable cruise control from the normal brake pedal switch, this is a redundant backup.

On the Ford masters I have seen this port is located at the very end of the second chamber, perpendicular to the major axis. On the vacuum system our E350 had, this port was pointing straight down, while on the hydroboost systems' masters it is clocked to the side. With the extra length of a hydroboost unit relative to a vacuum booster, the bottom mounted switch intersected with the ABS computer in our setup ('05).

-e

 

[nely]

Your abs module should be on the framerail if you have 4 wheel abs or rabs for that matter. Either way there shouldnt be clearence problems on the van so either would work. Id use the one not needing brake line adapters.

Sent from my SGH-T959 using Tapatalk

 

[Jakey]

The SCDS switch location will vary depending on the application.
If it's MC mounted and located wrong, you won't be able to open your fusebox.

I recommend getting an MC for a 1996 F450 with cruise since they have it on the bottom of the MC and 45 deg. to the passenger side, or going non cruise MC, plumbing in a brake line tee and placing the switch elsewhere.

If you would run any other size MC, the actuator rod should work but the mounting holes will need slotted.

 

[carcrafter22]

Great info everyone. I think it would be easiest to just go with the e450 master so it matches the hydroboost, if anything I could always install a T to put the CC sensor in or maybe I can get a master with the proper fitting. I should be heading home in a week to start swapping parts. I'll post up pics when I start.

 

[carcrafter22]

Finally made it home and started on the hydroboost conversion. I am using a hydroboost and master cylinder for an 98 E450 van the first thing I noticed was the bolt pattern is completely different. The bolt pattern on the E450 is smaller than the E350. To remedy this I removed the studs from the hydroboost and put it in place marked all 4 holes then drilled them out on the hydroboost plate. I chose to redrill the hydroboost because I didn't want my firewall looking like swiss cheese I also know from experience too many holes in that area can weaken the firewall and cause problems. The hydroboost itself is in place at the moment and the replacement gearbox is bolted in. For some reason the hydroboost didn't ship with the internal rod so I have to hunt one down somewhere(who knows). It looks like the E450 master will work with my E350 brake lines so that's good news.

That's as far as I've gotten today I just got in yesterday so were off to the movies to see Kung **** Panda 2 with the kids. Should have it wrapped up tomorrow except for the pressure lines and internal rod that will probably have to wait till Monday.

 

[nely]

Mondays a holiday. Unless your going to the junkyard, tuesday is the next day for the dealers i believe.

Sent from my SGH-T959 using Tapatalk

 

[sidcro]

Randy
I just found your blog on hydroboost.
I'm impressed.
Sounds like you might know what you are doing and that you worked hard on this.
How did the brakes work out?
I must say that I have never dealt with a potential seller ( or buyer) who was less communicative than you.
You must have lots of options, or your legal problems are all consuming. If the latter is the case than I am sorry.
It sounds like you are decent guy and a very hard worker.
I've got some money in the bank so let me know what your bottom line is and I'll let you know if I can swing it.
Sid