The reason they don't work so great in reverse is that the ancient relic known as drum brakes use a cam action to work, but only when rolling forward.

<a href=https://answers.yahoo.com/question/index?qid=20101127152927AAOfYbt>This</a href> post that I stole from Yahoo! Answers explains it better than I ever could:

 

Hi Dixie,
All that is true. That's why they don't work as well in reverse. But it my thought that they should still work in reverse.

How else can I explain all my other vehicles being able to hold, easily I might add.

Thinking about it, I have a theory. I will try to test it.

I think it might be a pressure problem. The amount of force needed to seat the drums on the bigger truck might take more effort than say my f150 shortbed 4x4.

It might take a brake pedal that increases the amount of pull on the longer cables and heavier hardware.

What would that be? The fulcrum effect.

This is where we need someone much smarter than me.

But for testing I can increase the pull on the rear brakes and see if it works.

Thanks,

Joe W

 

i wonder i your front cable need to be tightened Joe.
under the cab on the driver side outside o the frame is the cable setup the two rear cables connect to the front cable with an adjustable bolt type deal. to make the e-brake hold tighter make the adjuster shorter.
unfortunately, most of the time the adjuster is rusted solid

 

I would like to see this "law"

 

I will have to check if it's free.
F350 1990 suggested a possible stretched cable, so I was going to see if the ft cable could be shortened, since the 2 rear are pretty fresh.

If it's free I will adjust that. If not I will experiment with it.

It rained all day yesterday so I didn't play in the drive way. My wife took the truck today.
I will play with it and see if it can be improved.

I tightened it up again and got it to hold by really pressing down hard.

Thanks for the suggestion.

Joe W

 

Do you honestly believe Ford is going to put a parking brake in a car that only holds in one direction? (Ford's lawyers would have flashing hot pink warning signs all over the dash, the parking brake mechanism, and owner's manual if that were the case)


From the US Code of Federal Regulations (Nat'l Highway Transportation Safety Board)

(1) Each singly driven motor vehicle not subject to parking brake requirements of FMVSS Nos. 105 or 121 at the time of manufacturer, and every combination of motor vehicles must be equipped with a parking brake system adequate to hold the vehicle or combination on any grade on which it is operated, under any condition of loading in which it is found on a public road (free of ice and snow).

(2) The parking brake system shall, at all times, be capable of being applied by either the driver's muscular effort or by spring action. If other energy is used to apply the parking brake, there must be an accumulation of that energy isolated from any common source and used exclusively for the operation of the parking brake.

(3) The parking brake system shall be held in the applied position by energy other than fluid pressure, air pressure, or electric energy. The parking brake system shall not be capable of being released unless adequate energy is available to immediately reapply the parking brake with the required effectiveness.

 

That's pretty vague and with a lot of gray areas. If you changed the direction of the vehicle, it will hold on any grade.

Ford has good lawyers and have dealt with lawsuits before (Bronco II rollovers, Firestone tires, etc).

Going back to the OP, I'm glad to hear it worked by pressing the pedal down harder as a temporary fix. Let us know what you find when you're able to look under the vehicle.

 

Man --- are you kidding?

What don't your understand about the word "grade" --- car goes up or car goes down---pointy end points up or the pointy end points down.

 

I understand it, but I could see that wording being a loophole. If the vehicle holds on a grade with it's front pointing downwards it technically does as required by law even if the vehicle wouldn't be able to hold when rotated by 180 degrees. It's all just perspective when you get lawyers involved.

 

Under FMVSS Nos. 105 it does specifically state "forward and reverse",

S5.2.1. Except as provided in § 5.2.2,
the parking brake system on a pas-
senger car and on a school bus with a
GVWR of 10,000 pounds or less shall be
capable of holding the vehicle sta-
tionary (to the limit of traction on the
braked wheels) for 5 minutes in both a
forward and reverse direction on a 30
percent grade.


Includes wording toward effort required to do so,

125Lbs if applied by foot, 90lbs if by hand. (again under 10,000lbs gvwr)

Odd they found it acceptable to limit it to five minutes though!

Yes should work in forward and reverse but it is common to loose effective hold in reverse, if shoes are worn out of adjustment by just a little bit hold suffers. If drums are at or near wear limit its even worse, best hold is when shoes and drums are new very little to no wear on them, cam action previously mentioned has all to do with it big shoe little shoe.

If rear brakes are in decent enough shape and properly adjusted it should hold "no load" at minimum.

 

Thats the wording I was looking for. No more loop holes.

 

Nowhere does that say in reverse or backwards

 

Thanks for the research guys.

That's pretty much what I would expect.

I see mention of a 30 deg hill. That's a big grade. My drive way is 8% where I normally park and higher on the way up.

To the people who mentioned turning your truck around to hold on a grade.

If you do that you could/would be pointing in the wrong direction on the street. Which is illegal and would be ticketed in places. Plus you can't do that on a 1 way street.

I haven't looked at mine again. But will in the next day or two I hope. Pretty busy this week.

turned out to be an interesting topic.

Thanks,
Joe W.

 

30 degrees is a REALLY BIG grade, that would be a 58% grade. But it was a 30% grade mentioned (which is still pretty steep at about 17 degrees).

 

interesting discussion ... i have owned many different american, japanese, and british vehicles and i dont recall any of them holding nearly as well in reverse as they did forward. i just came to accept it as normal. i am old school, i almost always apply my parking brake, even point my wheels to, or away from, the curb, as the situation dictates, but the real holding is done by the transmission, whether auto or manual.

had an auto trans parking pawl in my hand once and remember being surprised at how small it seemed ... but i have never heard of one breaking under normal use.