Single reservoir master cylinder on deuces ?

[Rattlewagon]

Proportioning valves are only used on disc brakes. What is used is a pressure differential valve. This is only useed so if one half of the braking system fails the spool inside the valve is pushed to one side to activate the switch for the brake light to indicate there is a failure in the brake circuit.

I see your point. The truck doesnt have a prop valve now so what would be the advantage to putting one on after moving to a multiple zone system... I saw the drawings and assumed it was indeed a prop valve.

so with that said, how would one calculate the requirments for volume and pressure needed from a master cylinder with two zones?

If I am thinking correctly here, the diameter of the MC pistion would be the most important part with the stroke or volume of the cylinder of the MC would be second.

Anyone have any experience with fluid dynamics?

 

[5_TON_TOMATOE]

Ever had a failure on a dual circuit system? I have, you lose more than half your braking ability.

It is like a small twin engined airplane, you are fine if the failure happens when you don't need 100%. But when if fails you in dire times, it can lead to more trouble, as in you THINK you can make it.

The most common failure point is the hoses. They are covered in rubber which protects the steel braid. Any break in the rubber lets corrosion in, then when the steel strength member is gone, the hose ruptures. It is far easier to see corroded tube steel lines, the paint blisters..

The use of silicone brake fluid is another problem area, it allows trapped water to migrate to the wheel cylinder, these don't catastrophically fail, they just leak BUT if you don't do correct PMCS, adding brake fluid every so often, it will eventually get you. And silicone brake fluid soaked shoes don't stop too well. Yes, you can clean the shoes with methylene chloride, IF you can find this solvent (hard since the Clean Air Act amendments and Montreal Protocol restrict its use). Or $50 for new shoes.

Finally, if you have a poppet breather on the master cylinder cap, consider retrofitting to the air vent line. Why? If you have a slow leak, a vacuum can build in the system. This will cause complete loss of braking since the wheel cylinders will retract to the point the master cylinder volume will not be enough!

My 818 has a tag that reads: Use silicone brake fluid only- Has this truck been upgraded? 1970 Kaiser

 

[BugEyeBear]

My 818 has a tag that reads: Use silicone brake fluid only- Has this truck been upgraded? 1970 Kaiser

My '71 M35A2 has the same sticker...
I don't think it is an upgrade.

 

[doghead]

Silicone DOT5 is the Standard Brake fluid.

 

[Rattlewagon]

I don't know, there is bunch of med duty trucks in junk yard all over I know of some international that use air brakes and the same disk as f4-550

I think the majority of the cost would be in the adaptation of the new parts. There is bound to be some intricate machine work and fabrication. Not that it would bother me, it would just get spendy.

I personally like the idea if an all airbrake deuce. Especially if it has parking brake chambers or maxi's.

 

[SasquatchSanta]

Rattlewagon wrote:

I personally like the idea if an all airbrake deuce. Especially if it has parking brake chambers or maxi's.

Wouldn't straight air brakes change the classification of the truck and/or the licensing requirement for the driver?

 

[Rattlewagon]

Rattlewagon wrote:



Wouldn't straight air brakes change the classification of the truck and/or the licensing requirement for the driver?

If the brakes are actuated by air alone, operating the vehicle will require a CDL with an air brake endorsement.

The conversion would probably generate an interesting conversation at inspection time I'm sure. But I think it could be worked out in the end.

It would be far easier to find a dual zone master cylinder with a pistion size compatible with the requirments for the truck and simply adding an additional airpack. This would be my first choice.

 

[emr]

I think M-35 tom has it, and I would like to ad, I think some of U guys want a different truck, just saying, i enjoy all types of tectalk, and this too, but for real, the ones u have work, for many many many years in all types of climates in all types of conditions, ...Randy

 

[Snarky]

I haven't had a catastrophic failure yet, but I keep my system inspected. Some people here have had failures, and they are people who also inspect their trucks. The bottom line is that there are six brake cylinders, several rubber/steel braid lines, meters of steel line, one quirky master cylinder, one mysterious airpack.

If any of these things springs a leak, or fails internally, the truck has no brakes, you have a mechanical transfer case mounted emergency brake controlled by a piece of wire trying to stop a 7 ton vehicle traveling ~50 miles per hour, good luck.

I think that it MAY be possible to use today's technology improve upon a braking system that was designed in 1949. There are any number of hydroboosts, dual circuit masters, air brake systems, disk brakes, and other technology that can be used to help make the M35A2 safer and less of a road missile.

 

[BugEyeBear]

There is nothing wrong with making improvements to the Deuce. Especially safety improvements!

Many of us update the filters used, we use better lubricants, we mount better tires, we install electric wipers, we restore & even improve the paint & seats.

WHY NOT improve what is arguably THE MOST IMPORTANT system on the truck?!?

Yes, the single circuit system is a good design that has served us well for many years.
Yes, it works well if it is maintained & if nothing unexpected happens.

BUT, a dual circuit system is undeniably a better & safer design!
AND, even the best maintained system can fail unexpectedly!
ADD TO THIS the fact that even a Duece that has been "fully restored" STILL HAS some 30-50+ year old parts on it!

I still have the stock brakes on my Deuces.
I check my brakes before and after every drive, and I make extra certain that my emerg brake is always in perfect working order!

But I'd still sleep better (AND probably drive them more) if I could install a proven dual-circuit system!

I'm just thankful that most Deuce owners practice similarly diligent PM on their brake systems.

-Bear-

 

[BugEyeBear]

SIDE NOTE:

I also collect, restore, & race British Sports Cars from the 50's & 60's.

Many of these cars originally came with single-circuit brake systems, drum brakes all around, bias ply tires, and no seatbelts.

Vintage Racing circuits REQUIRE that dual-circuit brakes be installed, front disks, modern tires, and of course seat belts. (Add to this roll cages, fire ext systems, fuel cells, master power cut-offs, etc. etc.) But that is for racing...

On the street, and amongst car collectors it is COMPLETELY ACCEPTABLE and EXPECTED that these same systems (brakes, seat belts, tires) be upgraded to more modern components. ALL OF THIS is designed to improve the safety of these cars, protect the owner's investment, improve drivability, and protect the other drivers who share the road. These upgrades are not looked upon as having a negative impact on the originality of the cars as it is recognized that these technologies simply weren't available/common when these cars were originally manufactured, but certainly would have been if available.

That's MY !

-Bear-

 

[Rattlewagon]

I think M-35 tom has it, and I would like to ad, I think some of U guys want a different truck, just saying, i enjoy all types of tectalk, and this too, but for real, the ones u have work, for many many many years in all types of climates in all types of conditions, ...Randy

I'm not familiar with what M35Tom is referring to. Can any more information be provided?

When the truck was designed it was customary and acceptable to have a vehicle with single zone braking. Today, this is not the case.

I read all the time on this BB where people are chided for driving vehicles whose repair is in question and what were to happen to our hobby as well as what the legal ramifications would be if something were to happen.

If the master cylinder were to be upgraded and if something were to happen and you were questioned about the braking system on the vehicle, you at least have the opportunity to say that you have done as much as you can in regards to safety.

I have driven many vehicles of the era and have had very few issues but I have had issues. On one occasion more memorable than I would care to participate in again was where a friend’s 63 Falcon split an otherwise healthy looking brake line and of course, we lost our brakes. We were getting off of the interstate and at the bottom of the ramp was a stoplight that was red. He steered it into the woods instead of hitting stopped cars. As a result, the Falcon was destroyed. But nobody was injured and that is the most important thing to remember.

But as you can see from what I have explained, he had a vehicle that had the proper maintenance. He had bled the brakes shortly before that and nothing looked out of the ordinary, but the line still failed.

How the truck was designed and built has no relevance from my perspective. Maybe an M35 isn’t for me but for what it would take to alter the trucks brakes to a dual zone system it seems the only responsible thing to do.

Some have argued that with due diligence and proper maintenance the truck is just as dependable as any other vehicle matching its description and that even with a dual zone brakes having a failure in part of the system doesn’t guarantee good brakes. Ill agree, but, if I were to have a failure in a dual zone system and only have the use of the remaining, functioning zone I will still have better brakes than having none at all.


I am not looking to reinvent the wheel in any way. Just make the wheel safer.


I apologize for the length but I tire of dancing around the point.

Thank you

 

[AceHigh]

I dunno. All a lawyer has to do is sway a jury that you were in there redesigning a brake system that was adequate until modified and suddenly the truck failed to stop after you made changes.

No problem if you are an engineer, but me...

 

[Rattlewagon]

I dunno. All a lawyer has to do is sway a jury that you were in there redesigning a brake system that was adequate until modified and suddenly the truck failed to stop after you made changes.

No problem if you are an engineer, but me...

If something happens to the brakes on a truck and things end up in court and your talking to a lawyer, Ill bet that truck has single zone brakes...

 

[frodobaggins]

Some of you guys are so scared of lawyers and civil suits that I wonder how you guys function at all. You gotta use some common sense of course, but don't come in knocking a reasonable discussion.

 

[Rattlewagon]

Some of you guys are so scared of lawyers and civil suits that I wonder how you guys function at all. You gotta use some common sense of course, but don't come in knocking a reasonable discussion.

I couldnt agree more. Would anyone really sacrafice their personal safety or their childrens for that matter (yes, my kids will ride in this truck) because of potential legal battles IF something were to go wrong?

didn't think so...

 

[BugEyeBear]

I would have to say that as long as you based your components on a proven system you'd be safe, even in court.

So if you used similar sized components to that of the A3 you'd have a good basis to stand on.

OR if you simply duplicated component sizes from the A2, just with a dual-zoned system you'd also be OK.

People install dual-circuit systems on old cars (that originally had single-circuit systems) ALL THE TIME! This isn't rocket science!

-I'd start with trying to obtain the specs for an A3 system.
-Alternately I'd linvestigate if our stock single-circuit mastercylinders were ever used on any other car/truck that later switched to a dual-circuit system, and then go fishing down that stream.

That's another from me...
(am I up to a dollar yet??)