Bullnose Enthusiasts Forum

Speed Control Upgrade

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ArdWrknTrk

Re: Speed Control Upgrade

Administrator

I managed to get by Staples on the way to work. (@3. 😉)

I'll be looking at all this and trying to sort it out.

Hopefully by dawn I'll have something to run by you and Bill, since I've never had speed control.

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

85lebaront2

Re: Speed Control Upgrade

Administrator

Ok, the electronic vs vacuum speed control:

1. Steering wheel switches are the same for both
2. Vacuum system uses a dump valve or a pair of dump valves depending on whether it is auto or manual transmission.
3. These are the "fail safe" so if the electronics fail to cancel via closing the vacuum valve and opening the vent, the servo is vented so the throttle is released.
4. Electronic speed control uses a servo motor and an electric clutch to pull the speed control throttle cable.
5. Electronic speed control clutch is fed through the switch on the master cylinder, hydraulic pressure opens the switch dumping the clutch so that if either the servo is stuck or the electronics fail to disengage the speed control you do not have a "Chevy motor mount moment".

To achieve the same safety function, a normally open (closed when depressed) switch on the brake pedal will serve the purpose.

Bill AKA "LOBO" Profile

"Getting old is inevitable, growing up is optional" Darth Vader 1986 F350 460 converted to MAF/SEFI, E4OD 12X3 1/2 rear brakes, traction loc 3:55 gear, 160 amp 3G alternator Wife's 2011 Flex Limited Daily Driver 2009 Flex Limited with factory tow package Project car 1986 Chrysler LeBaron convertible 2.2L Turbo II, modified A413

ArdWrknTrk

Re: Speed Control Upgrade

Administrator

Thank you for this!
It's where I was going when I glanced at the prints, but I haven't had time to think about it.
Things were pretty hectic when I arrived

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

mat in tn

Re: Speed Control Upgrade

In reply to this post by Tarheel Blue

that's my plan for tomorrow

ArdWrknTrk

Re: Speed Control Upgrade

Administrator

This post was updated on .

Okay, I see these are largely answered.questions.

Ground is right there....

Clutch interlock is a simple jumper (really simple, if you're using the bullnose cab harness)

The damn firestarter master cylinder switch... 🤯
As I posted about my neighbor Ben's truck fire over a decade ago.....

I don't think it needs hot at ALL TIMES, It could easily be power in start & run instead of constant.
Closed except when brakes applied.
We can figure out a way to rig this without the master cylinder that Ford screwed up.
(or you could get one with the proper diaphragm material that won't go up 🔥

IDK about the bullnose speed input v/s my tone ring in the pumpkin.
I guess it depends on how many pulses per mile the PSOM produces vs the Bullnose VSS.
There are a million cheap solutions to this...
Cheap ES32 chip to interpolate one signal to another output?

I'm really not sure which harness you're using, or where it interfaces with the existing..?
What else do we need to look at?

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

Gary Lewis

Re: Speed Control Upgrade

Administrator

The number of pulses/mile or revolution doesn't matter. The speed control just keeps the number of pulses that were being generated when you hit Set the same.

But apparently the Bullnose pulses are the same as what was expected in the 90's as my speed control picks up or drops off 1.0 MPH each time that Set or Coast is hit.

And you are right, the brake switch should never have had power all the time. Mine gets switched power and works great. And Bill is right, a switch on the brake pedal would suffice to get that safety back.

Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

ArdWrknTrk

Re: Speed Control Upgrade

Administrator

Two things Ford engineering screwed up.
They drew the fuse on the trailing side of the switch.
They speced Kapton for the diaphragm, and it's not resistant to glycol.

The brake master switch could be plenty safe.
And using actual hydraulic pressure is about the most failsafe way to do that.

(still burned my neighbor's truck down) I told him. People don't want to listen to me.

I had pictures, but Flickr went subscription and I 🤬

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

Gary Lewis

Re: Speed Control Upgrade

Administrator

Right on all counts. You just have to gently touch the brake pedal on Big Blue and the speed control shuts off. Unfortunately Kurt doesn't have a switch on his master cylinder. Maybe this would be a good time to do the master cylinder upgrade?

Gary, AKA "Gary fellow": Profile

ArdWrknTrk

Re: Speed Control Upgrade

Administrator

I don't know if the one I keep showing from uhaultruckpartsonline has the port.
I know it's still listed but I don't think U-haul wants drivers being lazy

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

Tarheel Blue

Re: Speed Control Upgrade

In reply to this post by Gary Lewis

I did the MC upgrade over 10 years ago. I installed an ‘87 version w/ the plastic reservoir so, I’m reluctant to change out my MC at this point Just to have a switch that seems redundant, because I think the stop lamp switch on the brake pedal serves the purpose of shutting off the servo. The ‘85 EVTM shows indicates that the stock stop lamp switch get 12v/ 15a at all times via fuse 1 and describes the function as “closed with brake depressed”

In stock form, in 1985, there were only two things that could get the servo to shut down.
1 - touch the brake pedal
2 - touch OFF on the horn pad

Am I missing something?

Kurt K
'85 XLT Lariat, 4.9L, NP435, 3.08LS, DSII, 130a 3G, PMGR, '87 MC, P235/R75

Gary Lewis

Re: Speed Control Upgrade

Administrator

In reply to this post by ArdWrknTrk

Kurt has a later master, but apparently not one with the switch. In this thread Larry/ratdude747 says that the Raybestos MC39634 comes with the residual pressure valve and a "reservoir level sensor". Is that possibly the port where the pressure switch would go instead? I wouldn't think they put pressure to a level sensor, but then I wouldn't think that they'd have two different master cylinders.

And, by the way Kurt, I don't know whether you have an F150, 250, or what as you didn't say in your signature. But the master certainly changes between them.

Gary, AKA "Gary fellow": Profile

Gary Lewis

Re: Speed Control Upgrade

Administrator

In reply to this post by Tarheel Blue

In stock form the vacuum dump also shut down the servo, so there were three things. But since the later system doesn't use vacuum you'd only have two ways to kill it - the brake light system and the Off switch. And if the fuse blows on the brake lights then you won't have that.

Gary, AKA "Gary fellow": Profile

ArdWrknTrk

Re: Speed Control Upgrade

Administrator

This post was updated on .

In reply to this post by Gary Lewis

Gary Lewis wrote

Larry/ratdude747 says that the Raybestos MC39634 comes with the residual pressure valve and a "reservoir level sensor". Is that possibly the port where the pressure switch would go instead? I wouldn't think they put pressure to a level sensor, but then I wouldn't think that they'd have two different master cylinders.

The '87/ master has a float switch and three pin connector on the side that trips the brake light, like the / '86 would if the combination valve shuttle gets off center.

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

ArdWrknTrk

Re: Speed Control Upgrade

Administrator

This post was updated on .

In reply to this post by Tarheel Blue

One alternative I can think of is to make up a brake line with a banjo. 💡

In motorsports/motorcycles we have banjo bolts with switches.
I'm sure there's a NC one instead of the NO that would act as a brake light.
https://a.co/d/aeJ0keE this one is NO but you get the idea.

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

ArdWrknTrk

Re: Speed Control Upgrade

Administrator

What's the thread pitch on the splitter block/combo valve?

My truck doesn't have one

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

Gary Lewis

Re: Speed Control Upgrade

Administrator

I don't know, but will look to see if I have one that isn't installed... (Haven't made it to the shop yet.)

Gary, AKA "Gary fellow": Profile

ArdWrknTrk

Re: Speed Control Upgrade

Administrator

I was just trying to come up with a safe and simple solution for Kurt.
I'm sure you (or he) can find the same switch I can.

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

ArdWrknTrk

Re: Speed Control Upgrade

Administrator

In reply to this post by Gary Lewis

The call-outs are on the section drawing IIRC.....

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

Gary Lewis

Re: Speed Control Upgrade

Administrator

I don't have a spare, and the illustration I found in the Brake section of the FSM, below, doesn't have thread sizes. And I know this is for the F350, but the illustration for the lighter trucks has even less info.

Do you remember where you saw them?

Gary, AKA "Gary fellow": Profile

ArdWrknTrk

Re: Speed Control Upgrade

Administrator

My 'special' mind has a filing system of its own.....

It could have been ANY of the section drawings.
Maybe it's the one on Keith's forum?

Maybe it's the drawing of one of the aftermarket ones I tried to show that member who wanted to gut his????

I am NOT good at knowing exactly where I come up with the minutiae I have in my head.

Just yesterday I was driving to my brothers and we saw a purple fence.
I turned to him and said it was OSHA Safety Plum.

He was incredulous.... (until I looked it up on my phone and showed him!)
Then he said "You are a (explitive) retard."

Yeah, I'm THAT GUY!

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

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