47-55.1 parking brake

[nvrdone]

ok, thanks for all the input. The pedals mounted to the left of the clutch seem like they would block the air vent but it may be a possibility.
So far I'm liking the one from Summit racing or that style. Seems like it would be the easiest to mount either between the door and the end of the seat. Another possibility is to mount it on the floor to the left of the shift, but that may be a bit too much of a reach.
So now the investigation begins. Wish me luck.

[_Ogre]

depending on your setup, look at mounting the lever sideways in front of the seat.

[51 3600]

Originally Posted by _Ogre

depending on your setup, look at mounting the lever sideways in front of the seat.

I've been following this thread knowing it won't be long before I'll have to solve the parking brake problem myself. Have thought about doing just the setup you mention Ogre. Seems very practical.
I'm saving the inner cowl side for fuse panel and don't have floor shift so don't want lone brake lever in middle of floor (4L60 gets in the way too). Stock bench seat means not much room between seat and door. Would be helpful if anyone has implemented this idea and had info/pics to share.

[dsraven]

some older city delivery cab over style trucks used a hand lever style park brake that sat in the door opening about where the seat back would be, bolted to floor. brake on=lever straight up, brake off = lever horizontal. could do the same idea with a hand brake from a center console style vehicle I suppose.
the toyota style straight out pull type could be more easily hidden under the lip of the dash but easily accessible. only the T handle would be seen unless the brake is on.

[nvrdone]

ogre: thanks for the idea of mounting the handle parallel to the seat. That may work well.
My first thought is to mount it to the left of the seat. Then run the cable thru the floor and back to the left end of the cross rod (?). That way the cable would pull equally on both rear brakes. But with mounting the handle in front of the seat I would just have to add a pully on the left frame rail.

[_Ogre]

keep in mind that it is a parking brake, not an emergency brake. one cable going to one caliper is good for a parking brake.

[leegreen]

So what is the difference between a parking brake and an emergency brake and how could you justify not having an emergency brake?
'never needed one so far' would be a weak justification for omitting a safety feature every vehicle built since the '30s has had.

[dsraven]

parking and emergency brakes are both an auxilliary brake system seperate from the service brake system. they are the same thing but if you use it when parking, to take strain off the auto trans park pin or because you drive a standard and need the extra peace of mind, then it is called a park brake. it can also be used in an emergency to help slow the vehicle should the service brakes fail. then it would be called an emergency brake. different manufacturers call it different things but just know the system may slow the vehicle and eventually come to a stop if used in an emergency, depending on the situation with vehicle weight and incline of the roadway, but it will likely not stop anything like the service brake would. they normally only work with the rear wheel brakes but some larger vehicles (like dual wheeled delivery trucks that use hydraulic brakes instead of air brakes) use a driveshaft brake for this. on regular vehicles the rear drum brakes are used and applied with the park brake. on vehicles with rear disc brakes some systems use a mechanism that applies the disc brake mechanically using the hydraulic brake caliper piston and some use a seperate drum brake located in the center area of the brake rotor. usually reffered to as the "top hat" design since the rotor looks like a top hat when it is removed. a lot of people don't use the auxilliary brake thinking they don't need it. on drum brakes the park brake system is part of the shoes adjustment so it actually helps to have it operational. if not used the cables sieze up or the mechanism in general siezes up. even if you have an automatic trans the park brake should likely be used when parking on an incline anyway. stop, apply the park brake, then put the trans into park. it puts the whole shifter and trans internal mechanism under less stress. in an auto trans there is a notched wheel on the output shaft and there ia a pawl activated into that notched wheel when the trans is placed in park. that is the only thing holding the vehicle in place when the vehicle is parked and no park brake is used. that pawl can be hard to release when the weight of the vehicle, through the gear ratio etc of the drive train, is resting on the pawl jamming it into the gear notch. it only makes sense to me to use the park/emergency brake (they are generally the same brake with different names).
google image automatic trans park mechanism for a pic. here is a link to a generic set of pics with trans in park and not in park.
https://streetsmarttransmission.com/...-parking-pawl/

[_Ogre]

parking brake is required in states that have inspections. a single disc brake used as an emergency brake probably has more stopping power than a poorly maintained drum brake system. just throwing out options. truk doesn't have a parking brake, it should but i never got around to it during the build

[mobileortho]

[QUOTE=dsraven;9236397]there is the electrically operated linear actuator style, like newer cars have. just a button on the dash. there is probably a kit out there somewhere. /QUOTE]

I bought a kit like that awhile back but haven’t gotten around to installing it yet.

[dsraven]

back in the day some guys who drove our original trucks would carry a rock or a firewood block in the box. when they stopped they would drop the block in front of the wheel as a park brake since the park brake was something they considered extra and not really needed. they were also the guys who said the service brakes work good but you have to pump them up a bit. they didn't realize the park brake helps in brake adjustment, they also probably never adjusted the service brake either. haha.

[nvrdone]

Ha Ha - Ive been carrying a block in the bed for years. Not because the brakes dont work good, but because I dont trust the park brake to hold on a slope. The bar that goes around the rod that goes thru the floor is worn to the point that it will not hold. So its time to do an up grade.

[dsraven]

kabwe aka bam, a fella with a build on here, put the electric actuator on his task force truck. he built it himself. his build is at this link
http://67-72chevytrucks.com/vboard/s....php?t=440079/

[dsraven]

BAM'S BUILD shows the electric actuator he built for the park brake on page 86 post 2150 if anybody is interested.
http://67-72chevytrucks.com/vboard/s...440079&page=86

[leegreen]

Originally Posted by dsraven

BAM'S BUILD shows the electric actuator he built for the park brake on page 86 post 2150 if anybody is interested.
http://67-72chevytrucks.com/vboard/s...440079&page=86

That is clever!

If you build something like that I'd give some thought to how you would release it from underneath with whatever tools are kept in the truck.

First hot day last spring, out of town, the wife's jeep battery suffered an internal thermal runaway and it shut off, coasted most of the way to the side of the road, tried a restart. Put it in park + brake to get out and look under the hood and that was all the battery had in it, could not even run 4-way flashers. I know (now) how to take the console apart to release the shifter, but without power to wind back the rear brake pistons it is just a large roadside brick. I had to have it towed to a place I could buy a battery and pair of vice grips. Thank goodness I knew what an almost too hot to touch battery meant, tow truck driver wanted to drop us off at the dealership - at 4pm on the Saturday of a long weekend !

[dsraven]

smarter than your average bear, huh LG. good thing you can think outside the box.
good point aboit electrically operated stuff. battery goes out and you're hooped.

[vintovka]

Here a couple of poor pics of the parking brake in mine showing both up and down positions. Its an unaltered one from the 84 k10 GMC donor chassis. The position and travel is such that its almost as easy to depress pedal with left foot or either hand when seated. Was considering altering it for easier foot use but have grown accustomed to it. It is also easy to use from outside of cab with door open. Release knob set up to dash is original 54. Sorry pics are upside down. Tried 3 times to fix and failed. If someone can help please do.

[mr48chev]

Lets see what that looks like when you aren't standing on your head.

I'll see if I can wack my way though the weeds to my truck and get a shot or two. My pedal is way too high but could be placed a lot lower pretty easily.

[vintovka]

Originally Posted by mr48chev

Lets see what that looks like when you aren't standing on your head.

I'll see if I can wack my way though the weeds to my truck and get a shot or two. My pedal is way too high but could be placed a lot lower pretty easily.

Thanks. Cannot get them to load right even if I purposely post them upside down. Any way i could refigure the park brake arm but not really an issue at this point. Happy they work and are reliable. Long ago the original old one slipped in a downtown high rise parking building and luckily only rolled into the aisle. They did tow it so wound up with sizeable tow bill at time. Chocked it after that until the chassis swap and "new" brake set up came along.

[1project2many]

Originally Posted by leegreen

So what is the difference between a parking brake and an emergency brake and how could you justify not having an emergency brake?
'never needed one so far' would be a weak justification for omitting a safety feature every vehicle built since the '30s has had.

That's a great question. It's been that way since at least 1981.
https://www.ecfr.gov/current/title-4...ection-571.105

FMVSS105 describes braking standards for most road vehicles. Most of the rules are built around stopping a vehicle within a given weight class, travelling at a specific speed, within a specific distance. S5.2 is titled "Parking Brake" and it's slightly different than the service brake standard. For most of us, the park brake standard is this: "Except as provided in § 5.2.2, the parking brake system on a passenger car and on a school bus with a GVWR of 10,000 pounds or less shall be capable of holding the vehicle stationary (to the limit of traction on the braked wheels) for 5 minutes in both a forward and reverse direction on a 30 percent grade." Vehicles less than 10,000 lbs are considered passenger cars.

For 11 months in 1981 the grade was decreased from 30% to 20%, but in December '81 the grade was changed back to 30%.

In a document dated 6-30-05 a representative of the NHTSA speaking in regard to changes to FMVSS105 stated "...the service brake system is required to function with a variety of failed components. The parking brake system on hydraulically-braked vehicles has never been required to provide an emergency brake function." I have not yet researched the accuracy of this claim, but here's the document with the claim.

https://www.federalregister.gov/docu...-brake-systems

I grew up with vehicles equipped with an "emergency brake" and I was taught to always think about how I would apply that brake if I needed it. I also think about how changing my rear brakes on my '99 Suburban to disc would reduce the effectiveness of the park brake when loading a car trailer. With the experience I have with inoperative and minimally effective rear disc/drum park brakes, I have to vote for larger drums on the 'Burban instead of discs.

[mr48chev]

If you have ever blown a wheel cylinder on a single piston master cylinder brake system you come to understand the emergency brake concept real quick. In those cases would far rather have a hand brake rather than a foot operated emegerncy/park brake.

[leegreen]

I'd intended my question as rhetorical, for light vehicles like our trucks 'parking' vs 'emergency' is just a word choice despite distinction made in the legislation.

Heavy vehicles with air brakes have true emergency braking as the brakes self apply if the system fails. Unlike our hydraulic brakes.

I regard the parking brake action of rear drums as superior to that you get with rear disk, regardless of the mechanical brake being part of the caliper or a miniature drum inside the hub. No personal experience with the sperate mechanical caliper some cars have / wilwood sells -but the pads look small

I'd never trust just having the rear wheels locked up for loading / unloading a car trailer or boat trailer. Service brakes applied, wheels chocked, locked up in 4wd - something to save you when the weight comes off the back wheels.

[vintovka]

Originally Posted by mr48chev

If you have ever blown a wheel cylinder on a single piston master cylinder brake system you come to understand the emergency brake concept real quick. In those cases would far rather have a hand brake rather than a foot operated emegerncy/park brake.

Thanks to where mine is i could use either hand or foot to engage it. Thats IF i remember its their in a panic.

[1project2many]

I'd intended my question as rhetorical, for light vehicles like our trucks 'parking' vs 'emergency' is just a word choice despite distinction made in the legislation.

I thought it was a good question. I often have to explain to company drivers that their training for testing the "emergency brake" each morning will result in brand new vehicles incorrectly being removed from service. I explain that today's vehicles have a "park brake" designed to hold the vehicle on a slight grade, not an "emergency brake" designed to stop the vehicle. Today's literature uses the term "park brake" so the explanation makes sense. But when you asked the same question I've been asking, about when the function of the brake changed, I thought I'd post what I'd learned. The thing that's really changed is what the driving public expects from the mechanical brake.

The fact that the mechanical brake is minimally effective and folks don't seem to care speaks to how little thought most people give to what to do if the service brakes fail.

If you have ever blown a wheel cylinder on a single piston master cylinder brake system you come to understand the emergency brake concept real quick.

Exactly.

[leegreen]

yes, and everyone drives automatic , sticks it in park and walks away, after 5-10 years of that they wonder why their park brake they never used does not work.

I haven't blown a wheel cylinder, but I have blown a brake line - in a panic stop.

go find the 1300HP comet crash video for a reminder that the tranny park pawl just makes noise if you try and use it to stop the car.