1972 F-250 2wd to 4wd build

[rattle_snake]

I found an o-ring that fits OK in PS pump cap. Considering drilling vent hole in cap. thoughts?
The plastic 80/90s Ford PS pumps had an o-ring sealed cap and a small vent hole.
It's still loosing fluid after bracket fix.

Thoroughly cleaned master cylinder lid and reservoir, and put a thin layer of RTV on the reservoir seal surface. It seems to have helped.

 

[rattle_snake]

Master is still leaking out of the vent dent.
I had sucked half the fluid out of both chambers, so not overfilled.
Not sure if this is from sloshing, or a defect.
It did this right out of the box, I had to bend the retention clip to get a super tight fit. That was 5 years ago.
Tiring of fucking with it. It drips directly on the slip portion gasket of the steering shaft.

The newer plastic style M/C are looking better and better.

I'm in planning phase of hydroboost, not sure if I can use the old M/C, but not wanting to at this point.

Found a few hydroboost units at salvage yards. Not sure if getting one is helpful vs a reman and eating core charge, or just run junkyard unit. Then all the hoses, brackets and so on. Stuff is 20 yrs old now.

Alternate plan is to get 1994 booster and M/C that would have been matched to these axles. Afraid this step may be a waste compared to hydroboost.

 

[rattle_snake]

I see people using cheby hydroboost units in fords. Are there benefits of the GM version, fittings, availability or ? Is there a specific year range and M/C that is a popular choice?

 

[Deleted Member]

Did ya get my PM?

 

[rattle_snake]

Yes but it didn't answer any of my questions above.
You need a break from limey, come down and do some body work on mine.

 

[Deleted Member]

Yes but it didn't answer any of my questions above.
You need a break from limey, come down and do some body work on mine.

Too dam HOT. Drive it up here. We are gettin pounded with flash flood warnings left and right, and the MOST rain I have seen in 20 years. Dang. Wait a bit and you might just be able to pick me up at the bottom of the hill. Bring a towel.

 

[rattle_snake]

Ya it's wet here too, pastures flooded. Nice for a change, but, reason I moved away from shitty soggy PNW as soon as I turned 18.
😎

 

[rattle_snake]

It would appear that ford/chevy/dodge all use same bendix or whatever hydroboost unit, so donor make is mostly irrelevant. So I picked up a unit at a local recycler out of a 2001 cheby 2500.

It would also appear that most any master cycler will bolt to most any booster, so I would assume the stud spacing and pilot diameter is the same....
Plan at this point is to attempt to use old master with hydro booster and get that working, then decide what to do with MC.

 

[gump1376]

Still fighting PS leak and steering noises.

Look at swapping over to the Chevy/Saginaw pump. I believe there are OEM brackets that fit the 460. I can't remember if you have the serpentine belt system or not. I've learned the Ford pumps are normally noisy and were when I first drove my crewcab, unless it's just the poping you're hearing, then I'm not sure unless it's cavitation.

Ya it's wet here too, pastures flooded. Nice for a change, but, reason I moved away from shitty soggy PNW as soon as I turned 18.
😎

Being from the Sea-Tac area myself, I'm glad I moved away from that place as well. HA! NM is getting pretty wet as well right now and it's 'sort-of' nice we're getting rain. Although having to mow all my weeds is getting annoying.

I like the final result of the rear bumper you've made. I may steal some of your ideas for my crewcab.

 

[rattle_snake]

Look at swapping over to the Chevy/Saginaw pump. I believe there are OEM brackets that fit the 460. I can't remember if you have the serpentine belt system or not. I've learned the Ford pumps are normally noisy and were when I first drove my crewcab, unless it's just the poping you're hearing, then I'm not sure unless it's cavitation.


Being from the Sea-Tac area myself, I'm glad I moved away from that place as well. HA! NM is getting pretty wet as well right now and it's 'sort-of' nice we're getting rain. Although having to mow all my weeds is getting annoying.

I like the final result of the rear bumper you've made. I may steal some of your ideas for my crewcab.

Hey Gump, good to see you over here.
Currently running a sag p pump, my 460 was from a van so came with it and goofy brackets. Running V-belts still. The cap surface is damaged, so I put an o-ring in the cap and it appears to have stopped leak. I ordered a new reservoir with dual returns and a tilted fill neck to support hybroboost swap.

 

[rattle_snake]

Decided to revisit the front bumper to address some shortcomings and bring up overall quality level to that of the rear bumper. During build I was on the fence about reinforcing the clevis mounts, skipped in rush to finish. After getting some feedback on bumper face defection if clevis is loaded sideways, I wanted to improve.

Added a pair of supports orthogonal to the face plate to prevent deflection of face. Even the short length of the clevis mount when pulled hard from the side will want to tilt, and deform the metal around it.

The supports tie into the frame mounts.

I also spent some time turd polishing the fit and finish. I reworked all the corners on the top, added radius and smoothed everything out better. Also redid the upper/outer edge radii, to a better quality level. More consistent radius, smoothed and filled in some remaining pits and low spots. Then sand and repaint.

The metallic silver rattle can leaves bad tiger stripes and rough surface from flakes. Figured out some ways to mitigate and hit final coat with extra fine scotchbrite pad.

 

[rattle_snake]

Trying to gather parts for hydroboost. The more I learn the more I don't know. The 2000 cheby hydroboost unit has the wrong length rods on both ends. The nitrogen accumulator is loose indicating it is empty. So its junk and wrong application

Thinking I should get a superduty unit with longer rods. Have to get a motorcraft to get the booster to master cylinder rod with it, or junkyard. or fab my own rod and use spring and clippy from old. if bore is right size, there are different flavors. Getting tired of this shit.

I bought a master cylinder for a 1994 F350 as that is what the axles are from. Current one leaks out of the lid.
The new MC rear port is 18mm, doesn't have the check valve. Is this for the front of rear? Assume rear as it is drums, BUT the old was is the other way, front port is rear brake. Check valve is 2x the cost of a new MC.

 

[gump1376]

Hey Gump, good to see you over here.
Currently running a sag p pump, my 460 was from a van so came with it and goofy brackets. Running V-belts still. The cap surface is damaged, so I put an o-ring in the cap and it appears to have stopped leak. I ordered a new reservoir with dual returns and a tilted fill neck to support hybroboost swap.

Yeah, I've been a lurker for quite some time. Just like a lot of other 4x4 forums. Most of them for the Yotas, but now with my crew, I've been looking at the ford builds quite a bit for ideas.

I believe I grabbed my pump from a van as well, but I'm running the 351W, so brackets are a tad different.

I'll be following your hydroboost set-up as I may need to swap to that later on as the vacuum at these elevations is barely efficient for great stopping power. But first I just need to do the general maint. on my brakes as it needs all new pads, rotors, etc. Then a new fuel tank. etc., etc. etc.

 

[Cowboy63b]

PP, ENGAGED!

 

[rattle_snake]

Yeah, I've been a lurker for quite some time. Just like a lot of other 4x4 forums. Most of them for the Yotas, but now with my crew, I've been looking at the ford builds quite a bit for ideas.

I believe I grabbed my pump from a van as well, but I'm running the 351W, so brackets are a tad different.

I'll be following your hydroboost set-up as I may need to swap to that later on as the vacuum at these elevations is barely efficient for great stopping power. But first I just need to do the general maint. on my brakes as it needs all new pads, rotors, etc. Then a new fuel tank. etc., etc. etc.

Now that it's on the road you should post some pics in the intro thread.
As far as it seem you have to go on your crew cab, remember where you started from... just time and $

 

[SLOWPOKE693]

Every time I open this thread I have to wipe the drool off my keyboard. Love this truck and all the super clean and well thought out mods you did to it.

 

[rattle_snake]

Every time I open this thread I have to wipe the drool off my keyboard. Love this truck and all the super clean and well thought out mods you did to it.

Thanks 'Poke. I'm enjoying finally driving it, still working the bugs out of it, one at a time.

Still have a list of things to go, trying to keep it drivable as I go.

 

[rattle_snake]

whipped up a rear support bracket for the power steering pump. This makes the mount a double sheer. There are 2 bolts on the back of the pump, one is concentric with another on the front, so it can still pivot to get belt on/off.
Instead of a zig zag I used a simple link and two DOM spacers. Easier to build in place.

With rear brace the pump is rock solid at any RPM/disturbance frequency. Reinforcing the front mount did helped some, but really needed the rear support.

 

[rattle_snake]

Brakes on my 72 F250 worked excellent from factory. Dual piston front discs, big drums in rear, dual diaphragm vac booster, 32" tall tire, worn out 390 2bbl. Fast forward to 1994 F350 axle swap, mild 460, 40" tires. Brakes are essentially the same, dual piston front discs, big drums in rear. Same booster, same master cylinder. Performance significantly degraded. Part of this was lower engine vacuum level (10-12"). The big tires directly reduce braking torque.

Ford hydroboost units are harder to find than the chevy favor.
If you buy a renam, they do not come with the booster to master cylinder push rod, spring or clip. The length of this pushrod is vehicle specific.

Ford SD unit

So that leaves a few options

• junk yard unit {perhaps just for core and MC push rod)
• reman HB plus rod (if you know what lenght you need, and can find one to buy)
• New ford Motorcraft, complete.

I found a Chevy HB in local JY for $80. Was too lazy to drive across town for a ford unit, but I should have. The pedal rod was significantly shorter. The MC rod was also significantly shorter. The pedal rod bore size is larger and would require a different bushing. The nitrogen accumulator was damaged and loose.

Ford vac booster pedal rod length = 9-1/8"
Chevy HB pedal rod length 5-3/4"
difference = 3-3/8"
Ford booster spacer 3-3/8" (magic?)

Ford MC rod length = 1" protrusion from face
Chevy MC rod length = flush to face

Ford MC stud spacing = 3-3/16"
Chevy MC stud spacing 3-1/4"

So several differences including mounting plates. This unit could be made to work. It would not allow a spacer on firewall, and rod will be short by mount plate thickness, which is OK and would move pedal height down, relocate brake switch.
Whould need to use a Chevy MC. A ford MC could be used, but would need mount holes hogged out and a longer MC push rod, or a rod spacer/extention. Also have to get a different nylon pedal bushing.

I choose to return the junk unit and buy a Motorcraft BRB33. This is for a 99 up super duty, although there are more than one flavor of those too. This gets me the rod lengths I wanted, correct pedal bushing bore, and a new high quality unit.
BRB33 pedal rod length = 7-1/4"
Firewall spacer needed 1-3/8"
MC rod length = 1"+ and square end

So I cut a rectange and drilled some holes to make a custom mount plate out of 3/16 plate. This allowed me to use factory captive nuts on pedal assembly, and some 2-1/2 3/8 studs. Quick and easy, no mods to truck.

To work with 1972 MC, the push rod is 0.060" too long. Easy enough to modify, once you figure out how to remove the retainer...
To work with a 1994 F-350 MC (BRMC38), the end just needed to be radiused. Pop it in your lathe...

Orientation/clocking
HB units can be installed at any angle, but there is an 'up', as installed by the OEMs, hoses on top. The mustang 4.6L is at roughly 90* and has a special MC with mount hole vertical, accumulator up. The older models have a drain channel on the 'bottom', newer ones do not have one.
I test fit the unit upside down. return lines pointed at header. looks kind of goofy, puts spool valve underneath, opposite of MC reservior.

Fittings
Newer (90s up) HB units have an 18 x 1.5 mm o-ring inlet and a 16 x 1.5 mm o ring outlet. The two outlets are on the same side. Older have inverted flare. Most convert to AN6, so the metric to AN adapter are easy to find. I would only use steel fittings for this application.

Hoses
Bumps have a 3/8 IF pump outlet and a 5/16 IF P/S box inlet. Some use IF to AN adapter and just AN6 to AN6 hose. I used 90* IF hydraulic hose ends and 90* AN6. My hoses are about 32" long. I bought hose ends and bulk hose to make custom length hoses, with proper end fitting clocking (due to the 90s).
Another option is field serviceable hose ends and matching Teflon lined hose. They are expensive and odd fittings (like 5/16 IF 90) are hard to find. There are both aluminum and steel version, suggest only steel. I could not find all the pieces in stock of any given product family at the time.

After test fit I adjusted spacer length to get pedal in same location so I would not have to move the brake light switch. I also added booger welds as clocking keys to the HB bore like the OEM plate.

differences in super duty vs bumpside mount plates.

I went with a new dual return pump reservoir for a few reasons. ACDelco 19207054. New one is intended to be mounted at an angle, but with cap level. The offset design allow more clearance to A/C pump to get belt on/off. Fits perfect. I was able to run a 1/2 shorter belt and get pump more vertical. This solved interference problem of fluid cooler return lines also.

After fitting hoses, I had them crimpled at local shop. Installed existing MC at this time with some washers to space it out. One change at a time.

I was going to bend hard lines off of HB and use shorter hoses, hidden down by steering shaft. This puts them near header and I was worried about heat transfer. So I kept things simple and just uses hoses with 90s and ran them forward, direct to pump/box.

So, how does it perform? Sensitive. Only needs light pressure to stop now. Any more locks up rear brakes. Guessing 2x-5x the assist level over vaccum setup.
I put some miles on it and it's going to be OK. One cheap AN to metic fitting is leaking. MC is still leaking badly.

Next step is the new Ford motorcraft MC, BRMC38, to match the axles I have. Rear circuit will get adjustable proportioning valve and a #10 residual.

 

[rattle_snake]

Thanks to Broncokyle88 and Provience for the tips and suggestions

 

[rattle_snake]

Completed the master cylinder swap. I chose to use the MC that matches the brakes/axles that I swapped in, which is a 1994 F350 4x4. a Ford motorcraft BRMC38. Fairly confident this vehicle had rear ABS. Rear axle has tone ring, sensor, wring. pedal ratio is approximately 5:1.

So what is the mystery fitting on the rear port? Which circuit is front/rear? Took me awhile to figure it out. Unfortunately I obsessively have to figure out every aspect of every detail to convince myself I'm doing things the most best-est way. The curse of the engineer, aside from not being able to spell or socialize.
The fitting can be a 'proportioning valve', or just an adapter. It's vehicle dependent. In the case of ABS equipped vehicles, it is just an 18x1.5mm adapter. So it does nothing. I originally bought a new Cardone MC but it was missing this piece. Could have harvested a rusty one from JY, but didn't know at that time is was just an adapter. So I decided to just get a Ford unit that is specific to the 94 F350 and complete with all fittings, sensors and wire harnesses. Everything in the brake system is new and of high quality.
So which line goes where? In this case the fitting size and line connection locations were both opposite of the old MC. Given this is a disc/drum setup, the MC piston with more volume is the front. Since bore diameter is same, then one with longer stoke is the front discs. Approximate stokes are 1.75 rear and 2.25 front, so ~75% bias. So the front brakes use the front piston with big flare nut.

The fitting are also on the opposite side (towards engine) so new hard lines were needed. Front was now too short, rear to incorporate new hardware. Front is now 1/2-20 thread 3/16 inverted flare and rear is 7/16-20 threads. The fittings are clocked past 90* so tried a few line schemes in scrap wire before going to tube. I removed the cruise control pressure switch and installed a 3/16 inverted flare plug.

In the rear circuit I added a Willwood adjustable proportioning valve and a 10# residual valve. Supposedly the residual valve partially counteracts the drum shoe return springs and reduces the amount of travel and hence time for rear brakes to react. I farted around with placement of adjustable valve for hours trying to also incorporate windshield washer reservoir that no longer fits properly, eventually gave up and ended up making a simple mount bracket off MC.

I left distribution block and existing front brake delay device in place, to minimize changes at a time. Ran lines similar as before. They are not perfectly parallel everywhere.

I used old lines to make a short loopback line to bench bleed the MC. Hookup everything up. Amazingly no leaks. A freaking miracle! This is round 3 of these lines. Bleed and test drive.
Rear brakes lock up first so adjusted knob a few times until full decrease of pressure to rear (claimed 57%). Rear still locks up. This is major improvement to old MC without adjustable valve. Now I can apply much more pedal pressure before rear lockup and utilize the improved assist from the hydroboost. The old vacuum system would just barely lock up rear with maximum pedal effort. The hydroboost with old MC was very touchy. The new MC has a different pedal feel, softer and more movement for better braking modulation. Test drive was limited so need some more miles and higher speed stops to fully evaluate. Initial guess is 2-3x improvement in braking performance. Will make the truck MUCH safer to drive, even at 6000# with big 40" rubber.

 

[Projectjunkie]

Thanks for the brake tech, I'll be searching it in the future

I'm not sure if it was mentioned...

But many of those 90s f350 MC are 1 1/8" bore, some are 1 5/16", and I believe the Fsuperduty is also 1 5/16" but those have hydro boost and rear discs

 

[rockota]

Thanks for the brake tech, I'll be searching it in the future

I'm not sure if it was mentioned...

But many of those 90s f350 MC are 1 1/8" bore, some are 1 5/16", and I believe the Fsuperduty is also 1 5/16" but those have hydro boost and rear discs

dorman's website can be manipulated to search on bore size as well. Works great.

 

[holdmypocket]

Thanks for the brake tech, I'll be searching it in the future

I'm not sure if it was mentioned...

But many of those 90s f350 MC are 1 1/8" bore, some are 1 5/16", and I believe the Fsuperduty is also 1 5/16" but those have hydro boost and rear discs

I'm lazy so I'm just buying this kit but he lists all of the parts in the description.. he also sells just the brackets in a separate listing if you want to go that route:

Included parts:
73-79 firewall to SD hydroboost bracket
Custom machined steel bushing designed to mate SD booster eyelet to factory bake pedal
Super Duty Brake Booster 1999-2004 style (Motorcraft BRB33)
Super Duty Master Cylinder w/ reservoir, 1999-2004 style (Motorcaft BRMC28)
Brake lines and adapter fittings to plumb master cylinder into factory proportioning valve
AN hose and fittings for steering pump to hydroboost
AN hose and fittings for hydroboost to steering box (or power assist for you highboy owners)
Rubber return hose, tee fitting and hose clamps (Comp Cam Gator clamps, only the best!) for return line from steering box and hydrobooster
 to pump
High quality grade 8 hardware for entire install


Insulated hose clamps and self tapping screws
Detailed instructions with pictures and info



1973-79 Ford Truck Super Duty Hydroboost brake booster kit F250 F150 F350 | eBay

 

[rattle_snake]

For my axles/brakes/pedal assembly the BRMC38 @ 1-1/8 is a good fit for pedal travel. The BRMC28 is 1-3/8 which is 50% more area/volume, or 50% less pedal travel. I would also assume the BRMC28 has a different bias of front/rear circuits for rear discs. Battle born pretty much says use for discs. They have a nice kit for dents. I have about $450 into mine with new ford parts. Could get it down to $200 with JY booster and reuse of existing MC.

I ordered some smaller 1.000" rear wheel cylinders. Currently I have 1-1/8 which I mistakenly ordered before I realized I had 94 axles, which had 1-1/16 for SRW F350. Given equal fluid pressure, the smaller wheel cylinder bore will exert less force on the shoes. 1-1/16" is -10% and 1" is -20% from existing.
Hoping the -20% from 1" wheel cylinder will allow the adjustable prop valve to be backed off from bottomed out and allow adjustment.

Also want to remove the delay device in front circuit. I don't think it is needed, plus the residual in the rear speeds up rear timing compared to front.

 

[holdmypocket]

What's next? Interested in seeing what you come up with for sliders.

 

[rattle_snake]

Back from my archery elk hunting trip. Got a 4x4 bull. Not easy with a bow, but got it done.

Installed the smaller rear wheel cylinders. PIA, different bolts, different size fittings. made a mess. Working on brakes sucks. With adj prop valve still at limit the rear end continues to lock up. There is more braking available to front but rear end starts to come around. But still a massive improvement over the vac setup.
Under heavy braking the rear end lifts significantly and there is little force on contact patch. So improved front braking capacity seems to make situation in rear worse. Not sure going down a few more sizes in wheel cylinder is worth effort.

current list for truck is;
fix shit as it breaks
paint job
seat cover
rear bumper sliders
Move fuel lines
Redo exhaust
Nitrous system
aux fuel tank
rear locker
T case doubler

 

[rattle_snake]

Swapped out the rear wheel cylinders again, to the smallest I could find, 7/8" bore. This is another -24% from current (1") and -40% from the original (1-1/8).
Results were noticeable, I get just a slight amount of rear lock up at end of max braking from high speed. I estimate being able to use 90-95+% of available front brake capacity. This is with Prop valve at max still. So I'm happy with performance at this time.

 

[rattle_snake]

I can't find a place to fill nitrous bottles in PHX area. I called all the usual places and nothing. Rethinking buying a kit for this truck unless I can get some sauce. Only other option is trying to find a mother bottle and build a filler hose.

 

[rattle_snake]

Put the old Ford to work hauling horses over to San Tan mountains for a ride with Mrs. rattle_snake for our 17th anniversary. Must have a trailer plug wiring snafu as it blew some fuses but electric brakes still worked. Otherwise it did fine, drives, stops and handles well loaded. The 40s/4:10 gears aren't great when adding another 5k or so, and lack of gearing is more apparent. But have to drive gentle with the horses anyway.

But overall it checks the box as a capable do-it-all truck. Can tow what I need with A/C blowing cold. Just hook up and go. Gets lots of looks and thumbs up when putting in work.