ob1 Posted May 5, 2009 Share Posted May 5, 2009 As an answer to a problem, here was a suggestion on one of our forums in South Africa. Rhe problem is with a short wheel base as the 90, it is common to have a situations where cross axile wheels are in the air (Left front and Right back). As we know these wheels will spin helplessly when CDL is engaged. To cure this, ARB's or Detroits at the back at least. Now the price come into play, as well as change of handling etc. How about this: Electric shut off valves installed on each of the 4 breaking lines, that you can switch on from the cab. When the two wheels are in the air, you switch each valve on these on, and by gently appying the brakes, stop them spinning, transferring the power where it is needed. Preferably install a buzzer when the system is active to stop some interesting breaking later (forget to switch off) Anybody tried this yet? Possible? Possible pros or cons? Regards Quote Link to comment Share on other sites More sharing options...
Mo Murphy Posted May 5, 2009 Share Posted May 5, 2009 Left foot braking is the cheapest method Mo Quote Link to comment Share on other sites More sharing options...
mickeyw Posted May 5, 2009 Share Posted May 5, 2009 Left foot braking is the cheapest method Mo ^^^ Like Mo said Use with caution though, over zealous use breaks half shafts. How do I know? Quote Link to comment Share on other sites More sharing options...
Aragorn Posted May 5, 2009 Share Posted May 5, 2009 a gentle application should be all thats needed, although you may find that trying to modulate brakes with your left foot is a tricky task. Might want to try it a little on the road (in a safe manner obviously) before trying to use it to get you out of trouble. Quote Link to comment Share on other sites More sharing options...
poohbear Posted May 5, 2009 Share Posted May 5, 2009 Could always fit 'fiddle brakes' which would allow you to brake an individual wheel as and when necessary - might mike your interior look a little like a JCB though! Dave. Quote Link to comment Share on other sites More sharing options...
landmannnn Posted May 5, 2009 Share Posted May 5, 2009 Electric shut off valves suitable for a braking system are around £90. For four of these and suitable switches/wiring/plumbling you could buy a detroit or get most of the way to an arb. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted May 5, 2009 Share Posted May 5, 2009 Electric shut off valves suitable for a braking system are around £90. Or $25 up in a variety of shapes and sizes. Quote Link to comment Share on other sites More sharing options...
Ex Member Posted May 5, 2009 Share Posted May 5, 2009 They are called fiddle brakes. Common for comp vehicles. Quote Link to comment Share on other sites More sharing options...
landmannnn Posted May 5, 2009 Share Posted May 5, 2009 Or $25 up in a variety of shapes and sizes. Are you sure? The non-electric ones are about that money. Quote Link to comment Share on other sites More sharing options...
BogMonster Posted May 5, 2009 Share Posted May 5, 2009 Left foot braking is the cheapest method I've never understood the logic in that - brakes apply equal force to both wheels thus the one with least resistance will still spin - borne out by the fact that while I have played with doing it once or twice out of curiosity while stuck and with time on my hands, I could never get it to make the slightest bit of difference in a practical situation. The exception would of course be with ABS fitted in which case the wheel that was "locked" (the one with grip) would have the brakes released which should work. I managed to break the ABS in my old Discovery trying it though Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted May 5, 2009 Share Posted May 5, 2009 Are you sure? No, I made it up Last time I looked electric ones started at around $25 but it was a while ago. No idea who/what/where I saw 'em before you ask Quote Link to comment Share on other sites More sharing options...
howard14 Posted May 6, 2009 Share Posted May 6, 2009 As an answer to a problem, here was a suggestion on one of our forums in South Africa. Rhe problem is with a short wheel base as the 90, it is common to have a situations where cross axile wheels are in the air (Left front and Right back). As we know these wheels will spin helplessly when CDL is engaged. To cure this, ARB's or Detroits at the back at least. Now the price come into play, as well as change of handling etc. How about this: Electric shut off valves installed on each of the 4 breaking lines, that you can switch on from the cab. When the two wheels are in the air, you switch each valve on these on, and by gently appying the brakes, stop them spinning, transferring the power where it is needed. Preferably install a buzzer when the system is active to stop some interesting breaking later (forget to switch off) Anybody tried this yet? Possible? Possible pros or cons? Regards My 1997 Volvo V70AWD Has a system called TRACS. It's very similar to this, except that it is totaly automatic, I can switch it off or on, but that is all.I think it works very well, in snow I seem unable to promote any wheelspin, just as I seem unable to lock a wheel when braking with the ABS. It can produce some shocks though, like when accelerating over a wet, fairly fast cattle grid, and feeling the BANG as it works. It's also got an LSD. That works too! As for off road on a LR, well, try it and let us all know.... Best regards. Howard. Quote Link to comment Share on other sites More sharing options...
ThreeSheds Posted May 6, 2009 Share Posted May 6, 2009 I've never understood the logic in that - brakes apply equal force to both wheels thus the one with least resistance will still spin - borne out by the fact that while I have played with doing it once or twice out of curiosity while stuck and with time on my hands, I could never get it to make the slightest bit of difference in a practical situation. I have used it once: Series One on a building site (I was young and irresponsible and they didn't fence them off in those days) and got a little cross-axled on 'slip'. I just got the wheels spinning slowly and eased on the brake with my left foot and it drove out nicely. Of course it might have been going to do that anyway as the spinning wheels finally cleared the goo, but it seemed to make a difference.. Strangely I had forgotten all about it until now and can't recall hearing of anyone ever using it. I just spent ten minutes trying to explain my thoughts on how it works - but I can't. I know torque will be re-directed, but the stumbling block is always that the torque required to move a wheel against a brake will always (in theory) be higher on the static wheel... Worth a try if you are stuck though? Quote Link to comment Share on other sites More sharing options...
ob1 Posted May 6, 2009 Author Share Posted May 6, 2009 So we need somebody to go off and try it... I will have a go at getting something like this up and running(or stopping). Might be a while Quote Link to comment Share on other sites More sharing options...
Aragorn Posted May 6, 2009 Share Posted May 6, 2009 the point is that the wheel thats still on the ground isnt neccesarily stuck, but the diff will shunt power to the wheel thats off the ground because its easier to turn. By gently applying the brakes, you make both wheels equally difficult to turn, and power will get split evenly between them. infact if anything, the wheel off the ground would probably become more difficult to turn, as the heat generated by the spinning wheel will make the brake pads on that side more effective... Clearly if your properly stuck its unlikely to help, as your still limited by how much torque you can apply, but it can help in some situations. Quote Link to comment Share on other sites More sharing options...
Peter_110 Posted May 6, 2009 Share Posted May 6, 2009 the point is that the wheel thats still on the ground isnt neccesarily stuck, but the diff will shunt power to the wheel thats off the ground because its easier to turn.By gently applying the brakes, you make both wheels equally difficult to turn, and power will get split evenly between them. infact if anything, the wheel off the ground would probably become more difficult to turn, as the heat generated by the spinning wheel will make the brake pads on that side more effective... Clearly if your properly stuck its unlikely to help, as your still limited by how much torque you can apply, but it can help in some situations. It's the friction inside the diff which makes this work. Even an 'open' diff acts as a very slight ltd slip. But don't expect much effect. It may equal to two persons pushing in a crossaxled situation where you apply the brakes modestly. cheers Peter Quote Link to comment Share on other sites More sharing options...
C18RCH Posted May 6, 2009 Share Posted May 6, 2009 I believe and i'm sure someone will correct me if I am wrong that it is illegal to fit devices that restrict braking on road vehicles. There is a security device on the market that is designed to lock off the brakes but has to be fitted to the clutch in this country due this restriction. As above left foot braking is cheapest option. Quote Link to comment Share on other sites More sharing options...
Peter_110 Posted May 6, 2009 Share Posted May 6, 2009 As an answer to a problem, here was a suggestion on one of our forums in South Africa. Rhe problem is with a short wheel base as the 90, it is common to have a situations where cross axile wheels are in the air (Left front and Right back). As we know these wheels will spin helplessly when CDL is engaged. To cure this, ARB's or Detroits at the back at least. Now the price come into play, as well as change of handling etc. How about this: Electric shut off valves installed on each of the 4 breaking lines, that you can switch on from the cab. When the two wheels are in the air, you switch each valve on these on, and by gently appying the brakes, stop them spinning, transferring the power where it is needed. Preferably install a buzzer when the system is active to stop some interesting breaking later (forget to switch off) Anybody tried this yet? Possible? Possible pros or cons? Regards You may find this interesting: Haultech traction control Quote: But here is a quick run down on how it operates: We put speed sensors on each wheel which normally consists of a thin steel disc with lots of 12mm holes in it that the speed sensor looks at. This disc just sits in behind the wheel over the studs. The latest way that we are doing this is to place a band of thin steel with the holes in it over the disc brake hub and have the sensor looking at that. The sensor normally mounts off the brake caliper mount bolts. For a drum brake the sensor plate sits on the inside of the drum and so does the speed sensor itself. The sensors (4 of them) are connect back to a computer that makes decisions about whether it should apply brakes to any wheel. The way it applies the brakes is by controlling air soleniod valves (like the ARB locker valves). The valves apply air pressure into 4 individual air chambers that apply force to the 4 brake master cylinder that apply the brakes to the 4 individual wheels via the existing wheel brakes. So this is why you need an air compressor to run the system. Also you can see that the individual master cylinder must have an individual brake line running to each wheel brake which is why you need "4 channel" brakes. If you only got 3 or 2 channel brakes (or 1 channel for that matter) then it doesent matter cause you just run extra brake lines and flex lines if needed. I don't think you get away cheap with this option. cheers Peter Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted May 6, 2009 Share Posted May 6, 2009 Isn't that just Land Rover's ETC but vastly more complicated plumbing? Seems to me the easy option for automated TC would be to find a land rover ETC ECU and ABS valve block from something and persuade it to work rather than faff about with haultech. Fiddle brakes usually add an additional caliper on the back wheels to remain totally separate from "road" brakes, you could do this on all four wheels either with the traditional levers or again use an ABS valve block or similar, or you could run line-locks - I've never heard of it being illegal to fit such things but it's possible. Quote Link to comment Share on other sites More sharing options...
nicks90 Posted May 6, 2009 Share Posted May 6, 2009 left foot braking does work, use it quite frequently when trialling and it does make a difference. Not the all singing all dancing difference a locker will make - but if i'm getting wheel slip on a steep climb or crossaxle, i gently apply the brake and it oftens pops through. if that fails then i immediately do the 'quick throttle blipping' along side the gentle braking and that usually does the trick. Not very sympathetic to the shafts and diffs - but my motor has to work hard for a living! Quote Link to comment Share on other sites More sharing options...
Off Road Toad Posted May 6, 2009 Share Posted May 6, 2009 Surely applying a braking force to a wheel is just the opposite of what you actually want? by the time you've worked out which of your wheels, as it's probably going to be more than 1, is spinning and applied the braking force , you'll then be possibly back on firm ground with your brakes firmly applied thus holding you back?. Just a thought, as i'm also aware of how quickly that traction control can/will also eat through your brake pads when used heavily over even a day or two. interesting tho. what about using a self returning type of activation like they use on the rear steer of monster trucks? you hold it on to steer, or in your case brake and as soon as you let go of the switch it returns to straight ahead or "unbraked"? Steve Quote Link to comment Share on other sites More sharing options...
BogMonster Posted May 6, 2009 Share Posted May 6, 2009 A guy who worked for Land Rover told me once that in testing they wore out a set of brake pads on a P38 Range Rover in less than 50 miles when ploughing around in mud with ETC going all the time. Quote Link to comment Share on other sites More sharing options...
Daniele Posted May 6, 2009 Share Posted May 6, 2009 I agree with you. Quote Link to comment Share on other sites More sharing options...
hattymender Posted May 6, 2009 Share Posted May 6, 2009 Another vote for left foot braking. But not LR. Moggy 1000 on wet grass and Nissan Serina on anything (carp traction with no weight in back) also works. Gentle application, just enough to slow the spinning wheel and off you go. Probably. But your left foot is used to stamping on the clutch and it's very hard to apply gentle force without practice. Quote Link to comment Share on other sites More sharing options...
missingsid Posted May 6, 2009 Share Posted May 6, 2009 Another vote for left foot braking.But not LR. Moggy 1000 on wet grass and Nissan Serina on anything (carp traction with no weight in back) also works. Gentle application, just enough to slow the spinning wheel and off you go. Probably. But your left foot is used to stamping on the clutch and it's very hard to apply gentle force without practice. Good thread I have been contemplating this for some time. Both of my motors are dead at the mo so I could not confirm to myself. This thread mirrors my thoughts so thanks. Marc. Quote Link to comment Share on other sites More sharing options...
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