sled_dog
1 ton status
you COULD do it, but its pointless. You can turn the front wheels, if I had rear steer I wouldn't think about cutting brakes.
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.
Cutting brakes, can someone explain a bit to me?
- Thread starter sled_dog
- Start date
84gmcjimmy
1 ton status
but it could still be at advantage couldn't it?
sled_dog
1 ton status
some reason I envision the front end just pushing
It would not work. He's right, it would just push through if it's not rolling. It works in the rear because it creates a pivot for the front to swing around. Locking the front would just reduce the traction/friction trying to move the front in the desired direction.
Try this. Get a short cardboard box and lay it on the floor. Something like a cereal box lain on its side, or even a piece of heavy cardboard. If you have a model car or something with turning wheels and steering that would be even better. Pick one end to be the front. Now, put your finger on one "rear" corner and push the other. Notice how it moves? If you picture tires on the front, turned the desired direction and also pulling, can you see how it all works together more-or-less to pivot on the braked tire with relatively little binding? Next, put a finger on the front left and do the same. Now you've eliminated one tire that otherwise would be pulling you the desired direction, and the rear is pretty much pushing into the "braked" corner. In fact, to pivot on that corner, the rear end would have to slide around side ways! A more complicated description would utilize force vectors and some trig, but this model demonstrates the issue fairly well I think...
Try this. Get a short cardboard box and lay it on the floor. Something like a cereal box lain on its side, or even a piece of heavy cardboard. If you have a model car or something with turning wheels and steering that would be even better. Pick one end to be the front. Now, put your finger on one "rear" corner and push the other. Notice how it moves? If you picture tires on the front, turned the desired direction and also pulling, can you see how it all works together more-or-less to pivot on the braked tire with relatively little binding? Next, put a finger on the front left and do the same. Now you've eliminated one tire that otherwise would be pulling you the desired direction, and the rear is pretty much pushing into the "braked" corner. In fact, to pivot on that corner, the rear end would have to slide around side ways! A more complicated description would utilize force vectors and some trig, but this model demonstrates the issue fairly well I think...
84gmcjimmy
1 ton status
okay I understand now. Thanks for explaining it to me /forums/images/graemlins/bow.gif
[ QUOTE ]
Typically the levers you've seen actuate small master cylinders that apply each rear brake independently. If you have a selectable locker, you can just put it in "open" mode and lock one wheel to try to pivot on the locked corner. How well it works depends on weight transfer and terrain. With an auto-locker rear, you put it in front drive and then you can apply only one lever to lock one side with the other free-wheeling. And with welded, it's like an auto locker except that you can not lock only one side and let the other free-wheel. Many people find that this works just fine and may work better than single side in some terrain and orientations.
Some also use line-locks, but they don't have levers and are not as easy/fast to use since they require hard brake pedal, apply lock, release, do maneuver, apply brake, release.
Physical installation requires considerable re-plumbing to get separate lines to the rear brakes but is not terribly difficult.
[/ QUOTE ]
Are you absolutely sure about this? It was my impression the lever still required you to push down the brake pedal first, then pull the lever to "hold" the fluid to the caliper.
If what you say is true, is there some sort of bypass required for regular braking? Elaborate on this a bit more and even a complete plumbing flow diagram would be helpful.
I'm going to order my CNC cutting brake kit and junk the Hurst Line Locks I currently have.
Good Topic guys! /forums/images/graemlins/peace.gif
Typically the levers you've seen actuate small master cylinders that apply each rear brake independently. If you have a selectable locker, you can just put it in "open" mode and lock one wheel to try to pivot on the locked corner. How well it works depends on weight transfer and terrain. With an auto-locker rear, you put it in front drive and then you can apply only one lever to lock one side with the other free-wheeling. And with welded, it's like an auto locker except that you can not lock only one side and let the other free-wheel. Many people find that this works just fine and may work better than single side in some terrain and orientations.
Some also use line-locks, but they don't have levers and are not as easy/fast to use since they require hard brake pedal, apply lock, release, do maneuver, apply brake, release.
Physical installation requires considerable re-plumbing to get separate lines to the rear brakes but is not terribly difficult.
[/ QUOTE ]
Are you absolutely sure about this? It was my impression the lever still required you to push down the brake pedal first, then pull the lever to "hold" the fluid to the caliper.
If what you say is true, is there some sort of bypass required for regular braking? Elaborate on this a bit more and even a complete plumbing flow diagram would be helpful.
I'm going to order my CNC cutting brake kit and junk the Hurst Line Locks I currently have.
Good Topic guys! /forums/images/graemlins/peace.gif
To my knowledge, though I can't say for sure on all brands, my statements are correct.
What you describe are line locks used to implement cutting brakes. These may be electrical or mechanical valves placed in line to "hold" the pressure when provided by the master cylinder.
The only plumbing diagram I have off-hand is the one posted above, but no internal valving diagrams.
Yes, there is a sort of "bypass" in them. From what I understand, when the levers are in the neutral position, the brakes work as normal with fluid/pressure passing straight through the cutting brake body. Once you engage one of the cutting brake cylinders, a one-way valve keeps pressure from back feeding on the system and sends the pressure generated by the cutting brake cylinder (note the different bore sizes?) to the indicated brake cylinder. It's basically just a mini master cylinder with a one-way valve keeping pressure going the wrong way.
[Edit] I would call up CNC and get the scoop straight from them. Maybe they can also provide the valving diagram.
What you describe are line locks used to implement cutting brakes. These may be electrical or mechanical valves placed in line to "hold" the pressure when provided by the master cylinder.
The only plumbing diagram I have off-hand is the one posted above, but no internal valving diagrams.
Yes, there is a sort of "bypass" in them. From what I understand, when the levers are in the neutral position, the brakes work as normal with fluid/pressure passing straight through the cutting brake body. Once you engage one of the cutting brake cylinders, a one-way valve keeps pressure from back feeding on the system and sends the pressure generated by the cutting brake cylinder (note the different bore sizes?) to the indicated brake cylinder. It's basically just a mini master cylinder with a one-way valve keeping pressure going the wrong way.
[Edit] I would call up CNC and get the scoop straight from them. Maybe they can also provide the valving diagram.
PJTPW
1/2 ton status
On the CNC brakes, you can lock the tire by pulling up on the lever only. The braking power comes from the cylinders in the cutting brakes themselves.
When not in use they are "open" and allow fluid to pass through the unit.
BTW I've used the cutting brakes a lot in the last few weeks, and I can lock up a 44" TSL with 4lbs in it on slickrock really easily. They have plenty of pressure to hold it locked. In sand you drag the locked tire a little more, but on slickrock, it pretty much pivots off the locked tire.
Ryan
When not in use they are "open" and allow fluid to pass through the unit.
BTW I've used the cutting brakes a lot in the last few weeks, and I can lock up a 44" TSL with 4lbs in it on slickrock really easily. They have plenty of pressure to hold it locked. In sand you drag the locked tire a little more, but on slickrock, it pretty much pivots off the locked tire.
Ryan
BadDog - again, You Da man! Thanks for the good technical info, you never cease to amaze me. /forums/images/graemlins/thumb.gif
Ryan, thanks also for clearing this up. Im even more stoked about getting the CNC setup. I have used my line loc setup for over 2 years now, but having the simplicity of the lever system, I will be good to go.
And the S-TON progress moves on... /forums/images/graemlins/pimp1.gif
Ryan, thanks also for clearing this up. Im even more stoked about getting the CNC setup. I have used my line loc setup for over 2 years now, but having the simplicity of the lever system, I will be good to go.
And the S-TON progress moves on... /forums/images/graemlins/pimp1.gif
Brought this one back to life. One question about the cutting brakes. Can you use your same MC witht he cutting brakes? Also What did you do with your proportioning valve without the rear brake lines going into it?
Anyone have anyexperience using the cutting brakes as an e-brake or would you not recommend this?
Anyone have anyexperience using the cutting brakes as an e-brake or would you not recommend this?
Everything can stay the same as without cutting brakes. The cutting brakes are inserted in the rear brake system downstream from the p-valve. Nothing upstream will 'know' the cutters are there.
It's generally a bad idea to use hyd brakes for parking brakes. The reason being that hyd brakes will bleed off pressure over time. So for a qwik jump out to check something, OK. For overnight or longer parking, NFG. I've posted this response b4 & I've had people post back saying that they've done it (used a hyd brake for long term parking). All I can say is that they are tempting fate and one day it's going to bite them in the arse. There are some things that shouldn't be done even though they're possible, this is one of them.
Those states that have more of a whole vehicle check (as opposed to just an Emissions Check like KA) may require a non hyd Emergency brake. No experience there.
It's generally a bad idea to use hyd brakes for parking brakes. The reason being that hyd brakes will bleed off pressure over time. So for a qwik jump out to check something, OK. For overnight or longer parking, NFG. I've posted this response b4 & I've had people post back saying that they've done it (used a hyd brake for long term parking). All I can say is that they are tempting fate and one day it's going to bite them in the arse. There are some things that shouldn't be done even though they're possible, this is one of them.
Those states that have more of a whole vehicle check (as opposed to just an Emissions Check like KA) may require a non hyd Emergency brake. No experience there.
sled_dog
1 ton status
Pennsylvanias law I know makes no mention of hydraulic vs mechanical. Their only mention is that the Emergency/Park brake has to be seperate of the service brake system. So Cutting brakes held closed would not be legal here. But a transfer case mounted E brake with a hydraulic setup would be legal.
blk87K5
1/2 ton status
UPS guy just brought my cutting brakes from Fun Runner, hope to get em installed in the next day or so and give them a thorough test. Im digging the chrome on everything.
