Emergency stopping questions

[panzerjunky]

In getting into these brake questions and reading the posts from fellow deuce owners as the the inherent dangers of the single circut brake system should the system fail.

so should the system fail what is the correct way to slow down 13,500 lbs of steel
I am guessing downshifting but what if you don't have the time to do this would you advise slamming it into neutral then grabbing the parking brake and applying pressure with that?

Also I see on e-bay someone advertises a cd to install dual circut brake systems for the M35 has anyone bought this or tried it i know there is at this time no "kit" availble to up grade to dual but I am understanding the A3 has dual circut brakes so it can be done has anyone tried it?
Thanks Jerry

 

[hndrsonj]

That manual is on SS. There are a couple parts you will not find or be able to get. More than likely, the PARKING (not emergency) brake will not stop you just slow you down a bit. Go through the brake system and ensure everything is working and you will be fine.

 

[Wildchild467]

I agree with hndrson..... plan B is always head for something soft and cheap

 

[gtsig]

shut the engine off (pull the kill switch) in gear. The engine will not like you for it but it will stop.

 

[Hawkshaw]

As we found out when I brought my duece home the emergency brake is good for one panic stop and then it is gone. We were only going 44 mph and it was all we could do to get it slowed down to keep from rear-ending the cars in front during a Birmingham traffic jam on I-59. Luckly the traffic began to move some when we got up there. The brakes were gone, when they go there is nothing left. Definately a pucker moment.

 

[rosco]

THE OLD "SINGLE SYSTEM" brakes were good. They were used for years. We didn't know they were dangerous. They seldom failed completely, and when they did, you could tell that before you moved the truck. When maintained properly, they are very dependable and serviceable.

Lee

 

[cattlerepairman]

THE OLD "SINGLE SYSTEM" brakes were good. They were used for years. We didn't know they were dangerous. They seldom failed completely, and when they did, you could tell that before you moved the truck. When maintained properly, they are very dependable and serviceable.

Lee

YES, WHEN THEY WERE NEW or constantly being rebuilt on schedule.

Fact is, that with 35+ year old trucks that often DO NOT get the care and maintenance they got in an environment where time, parts expense and manpower did not matter, there are trucks out there - and it may not be yours - that run a higher risk of brake failure than ever before. While there are failure modes that do give you warning (a slow leak at a brake cylinder that may not get much worse) there are also failure modes where the truck stops perfectly fine one moment and then you have no brakes the next (blown flex hose). So - it depends (coincidentally the product you want to have handy when it happens to you, downhill, loaded).

Many trucks out there may get better treatment and PM now than they got in the service and those are the owners that know darn well that running these trucks sensibly requires more than buying one, driving it off an on and ignoring it for the rest of the time until something obviously breaks.

You can enhance your chance to stop by having a larger brake reservoir (i.e. more brake fluid volume) so that you might have line pressure longer for that last stop when the life blood is draining away through a brake leak.

PM on the brakes is paramount and there is no such thing as "paranoia" when it comes to single circuit system maintenance.

 

[Parker2]

YES, WHEN THEY WERE NEW or constantly being rebuilt on schedule.

Fact is, that with 35+ year old trucks that often DO NOT get the care and maintenance they got in an environment where time, parts expense and manpower did not matter,.

There is no excuse for any owner of a vehicle not to make sure that the brakes are 100% operational on a regular basis. The age of these trucks shouldnt matter if you go thru the brakes and maintain them properly. There shouldnt be any 35 year old parts in the brake system.

 

[juddspaintballs]

toss an anchor in the bed and fling it out the back in case of emergency

honestly though, as long as it's maintained, the brake system shouldn't be a safety issue at all. in the event of a failure, however, gtsig's suggestion of killing the engine while in gear followed by a smooth and firm application of the parking brake should be enough to stop you pretty quickly.

 

[LanceRobson]

shut the engine off (pull the kill switch) in gear. The engine will not like you for it but it will stop.

This won't help much. Unlike a gas engine the diesels don't have a throttle plate in a carb or throttle body.

On a gas engine when you go to idle and the throttle plate closes the pistons are pulling against a partial vacuum on each intake downstroke. That partial vacuum has the effect of pulling up on the piston dome. As a result a gas engine has significant engine braking potential.

On a diesel ehgine the only braking you will get is from friction. The air is not restricted by a throttle plate so each piston gulps a full load on every intake stroke. On the compression stroke is is compressed, which does take a lot of energy, but the air is now sitting there as potential work. When the piston starts back down it is being pushed by more than 250 PSI of pressure.

The end result is that driveline friction, engine bearing friction and any accessory loads are all the braking that's going on.

Driving defensively and trying to keep a good space cushion in front of you is an important safety techinque. On a road with a single lane in each direction that is pretty easy. In heavy traffic on a highway with multiple lanes you may want to drive about 2-3 MPH slower than traffic. That creates a self propagating space in front of you. You will find that you average a lot more room in front of your bumper than if you drive the speed of traffic.

Lance

 

[jesusgatos]

Good point Lance. What about if an air cutoff switch is installed though? That would behave similarly to a throttle body / butterfly closing, right?

 

[Hawkshaw]

jake brake

 

[jimm1009]

Suffice it to say, all owners should go through their wheel bearings and brakes when they pick up their new rides.
That is the ONLY way that you can know what YOU really have.
A single circuit system is good and will last for several years but you have to step over that line in the sand to start somewhere.
Rebuilding or replacing all the wheel cylinders, the air pack, and the master cylinder is the only way to go if you want to ensure 100% integrity of the system of your truck. This also includes checking all the soft hoses (5 total) and inspecting all the hard lines for chafing, rust, etc. Also adjusting your brakes per the TM will help ensure maximum efficiency.
Just my 1.7 cents worth but if a 1946 CJ2A can have it's brakes last for 30 + years with general upkeep, then so can an old deuce.
jimm1009

 

[wreckerman893]

I agree with doing proper PMCS on your vehicle...but even with all that there is the Murphy Factor.....anything that can go wrong will...usually at the worst possible moment.

Instant brake failure (pedal goes to the floor with a baaaaad THUMP sound) is very rare in a deuce...if you are leaking fluid you should smell it and see if (if you do a walk around inspection every time you stop).

If it does and you are not in a panic stop situation you can downshift until you get to 28 MPH....shift up to 5th and drop her in LOW RANGE......you will slow down.
If you leave it in 4th you may lock up the rear wheels but you will slow down even faster (not reccommended), usually with your face on the rim of the steering wheel.

I have driven short distances in low range with NO BRAKES AT ALL but it was in an emergency and almost no traffic. The parking/emergency brake will help slow you down but with any kind of load on it is more wishful thinking than reality.

 

[williamh]

I Agree , i am doing a brake job on a friends shop van ... it started with the every month start ... break pedal went to the floor , didn't have any problems until straight to the floor, started pulling the wheels , found bad bearings, one installed wrong ... inside bearing on outside ..( how can you do that ?? ) all of the wheel cyl. leaked and had to be replaced/rebuilt, master cyl. replaced, im still not done .. found tires with damage between duels .. if your going to fix it .. do it all !!