I need to borrow an 87-89 USAF dual circuit master cyl. mount temporarily

clinto · Dec 5, 2016

I am in the process of trying to manufacture the hardest part of the dual circuit conversion: the master cylinder/ pedal assy. mount. If I can bring this to market and find a master cylinder, then peope can add their own 2nd airpack, bend some brake lines and have a factory designed and tested dual circuit system and do it on a budget.

Problem is, my manufacturer needs an example to 3d scan. My truck has one but it's my only running deuce right now and I just went through the brakes last year, so I am loathe to take it apart.

Does anyone out there have an '87-'89 USAF truck that is not running or is taken apart that they can send me the bracket? I'll only have it for 60-90 days and I'll pay for all the shipping.

If you can help me with this, I'd sincerely appreciate it.

Thanks

bachman502 · Dec 5, 2016

Is this the mount that is different if you have a winch?

yolner · Dec 5, 2016

I hope you find a way to make this happen. Would be nice to have a stock option for more reliable brakes.

clinto · Dec 5, 2016

bachman502 said:
Is this the mount that is different if you have a winch?

All 1949-1986 M44/G742 series trucks equipped with a front winch use a U-shaped bracket that bolts to 2 threaded holes in the single circuit master cylinder.

1987-1989 USAF dual circuit trucks use a different master cylinder mount which allows the modern aluminum dual circuit master cylinder. The associated hardware (clutch and brake pedals, shafts, etc) are the same or interchangeable (the USAF trucks did have taller pedals, but they're otherwise the same).

Since the new, aluminum master cylinder is shaped in a way that the PTO shifter bracket can't mount to it, they designed the dual circuit mount to have an "ear" cast into it. It's actually pretty clever, you can use the earlier PTO handle and everything. The old PTO handle simply bolts to the ear where it used to bolt to the U-shaped bracket. So you can use all the early stuff on a later truck (and vice versa).

All USAF dual circuit trucks have the ear cast into the mount, regardless of whether they have a winch.

Single circuit:

And dual curcuit:

frank8003 · Dec 5, 2016

http://www.steelsoldiers.com/showth...rake-Engineering-Thread&p=1496631#post1496631

Had one complete sold it post 109
but thread has all information you need like....

ID: 478054I found out that all the 1987 to 1989 M35A2C trucks came with the bracket to mount a PTO handle. Here's some pictures.
Thanks Peashooter.

frank8003 · Dec 5, 2016

The air tanks are different also and the MC are expensive

saddamsnightmare · Dec 8, 2016

December 8th, 2016.

But not as expensive as either wrecking the truck or running someone over on a brake systems failure..... It does amaze me that they scrapped the M151's and let the unmodified deuces out.......

clinto · Dec 8, 2016

frank8003 said:
The air tanks are different also and the MC are expensive

There is a lot of difference between the 1949-1986 system and the 1987-1989 system. The M44A3 system is roughly the same, except it uses a master cylinder mount that won't really work, as it has no provision for a clutch pedal. Yeah, you can make it work, but it's not good enough for me.

The 1987-1989 system has a pressure switch in it, like modern vehicles, to alert the operator to issues. This switch activates the parking brake light on the instrument cluster. This is the same as most 1960's cars.

One of the air tanks is deviated-it has two drain cocks on the bottom, one for each chamber. I figure installers can add a third tank on the right side of the frame, across from the stock airtanks in order to copy the factory split system. If you're really ambitious, you could cut your tank in half, weld a baffle in it, drill and tap a hole for the drain, pressure test it, then weld the two halves back together.

I'm working on a master cylinder that's reasonable.

saddamsnightmare said:
December 8th, 2016.

But not as expensive as either wrecking the truck or running someone over on a brake systems failure..... It does amaze me that they scrapped the M151's and let the unmodified deuces out.......

I think the deuces had been surplussed since the 1950's, so stopping surplus of them after thirty years probably seemed like shutting the gate once the horses were out.

I think the 151 story is pretty interesting. Read posts #4 and #9: http://www.steelsoldiers.com/showthread.php?46859-M1152A1-Performance

rustystud · Dec 9, 2016

clinto said:
There is a lot of difference between the 1949-1986 system and the 1987-1989 system. The M44A3 system is roughly the same, except it uses a master cylinder mount that won't really work, as it has no provision for a clutch pedal. Yeah, you can make it work, but it's not good enough for me.

The 1987-1989 system has a pressure switch in it, like modern vehicles, to alert the operator to issues. This switch activates the parking brake light on the instrument cluster. This is the same as most 1960's cars.

One of the air tanks is deviated-it has two drain cocks on the bottom, one for each chamber. I figure installers can add a third tank on the right side of the frame, across from the stock airtanks in order to copy the factory split system. If you're really ambitious, you could cut your tank in half, weld a baffle in it, drill and tap a hole for the drain, pressure test it, then weld the two halves back together.

I'm working on a master cylinder that's reasonable.

I think the deuces had been surplussed since the 1950's, so stopping surplus of them after thirty years probably seemed like shutting the gate once the horses were out.

I think the 151 story is pretty interesting. Read posts #4 and #9: http://www.steelsoldiers.com/showthread.php?46859-M1152A1-Performance

Actually haven driven this little death traps in the Marines I'm glad they never allowed them to be sold. I almost rolled one just doing 20 MPH on base once. Yes they where great little goats out in the boonies as long as you where going under 10 MPH. Most of the guys in the motor pool would rather drive a 5 ton then one of the M151's . I actually preferred driving the Tanks. Never had a problem with "rollovers" with a Tank. Just a problem with what I rolled over !
:tank:

A Blind Man · Dec 10, 2016

I'd definitely be interested in something like this, Recently purchased a deuce and am going to overhaul the entire brake system once i get a chance to get it all apart. I've been hunting at the local truck parts lot through the deuces/5 tons that they have hoping to luck out and catch one with a dual circuit, but no dice yet.

clinto · Dec 10, 2016

A Blind Man said:
I'd definitely be interested in something like this, Recently purchased a deuce and am going to overhaul the entire brake system once i get a chance to get it all apart. I've been hunting at the local truck parts lot through the deuces/5 tons that they have hoping to luck out and catch one with a dual circuit, but no dice yet.

I am determined to bring this to market and I have two extremely competent friends with manufacturing expertise in my corner, so I am confident I can make one. Question is going to be at what price and how many do I have to make and how many master cylinders to I have to buy in order to get them cheap enough to bring them to market.

If I can unravel the master mount and master cylinder part of the mystery, then users can find their own solutions to mounting the second airpack, 3rd chamber on the air tank, etc.

A Blind Man · Dec 10, 2016

clinto said:
If I can unravel the master mount and master cylinder part of the mystery, then users can find their own solutions to mounting the second airpack, 3rd chamber on the air tank, etc.

Agreed, there is enough places to tuck stuff away on the frame you could prolly stash an entire extra deuce under there.

yolner · Dec 10, 2016

clinto said:
I am determined to bring this to market and I have two extremely competent friends with manufacturing expertise in my corner, so I am confident I can make one. Question is going to be at what price and how many do I have to make and how many master cylinders to I have to buy in order to get them cheap enough to bring them to market.

If I can unravel the master mount and master cylinder part of the mystery, then users can find their own solutions to mounting the second airpack, 3rd chamber on the air tank, etc.

Do you really need to include the master? Offering it as an optional addon might be good, but I think most people around here would rather just get the bracket to mount it.

clinto · Dec 10, 2016

yolner said:
Do you really need to include the master?

No.

yolner said:
Offering it as an optional addon might be good, but I think most people around here would rather just get the bracket to mount it.

That's my plan; I'm going to offer the kit both ways. With and without. Reason I'm working on finding a master is that the correct ones are hard to find and expensive. I am going to find a better solution.

yolner · Dec 10, 2016

clinto said:
No.

That's my plan; I'm going to offer the kit both ways. With and without. Reason I'm working on finding a master is that the correct ones are hard to find and expensive. I am going to find a better solution.

Ohh didn't realize that's what you meant. Using something cheaper and easier to find would be great.

clinto · Jan 23, 2017

Ok, before I ask someone to take their truck apart, does someone have one of these that they've already removed and hasn't gotten around to installing it yet? I only need it for a month or so and I'll send it back ASAP, I promise.

Thanks

texas30cal · Jan 23, 2017

I just got a air force truck for parts (blue paint underneath) of unknown year, but I just went and looked, it has single air pack, sorry I couldn't help.

bachman502 · Jan 23, 2017

I really would love to see some development from this thread. There seems to be way to many threads that just die off regarding the dual circuit brake solution. Hopefully somebody can help.

frank8003 · Jan 23, 2017

I sold the entire rig, complete, cut out of a truck
search "survival 109 build"
Post 112, 198, and 310 and on
He has posted all the pictures and has all the information you desire

Had it for sale long time
Nobody wanted the setup until Rayzer and Quadjeeper arrived one day and then it was gone.
Ask them for the help you need.

Picked up the parts to convert my single circuit brake system to the Air Force truck dual circuit system. Planning on doing the conversion sometime this winter.
View attachment dual brakes quadjeeper 09262014.docx

frank8003 · Jan 24, 2017

what it is what it was
Hanging in the tree

I need to borrow an 87-89 USAF dual circuit master cyl. mount temporarily

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