Thread: Use of handbrake on downhill

Originally Posted by Blknight.aus

so far landrovers work on 60% approach/depart and 40% side I think it even holds for a Freelander.

0 degrees=0%=flat ground
90 degrees=100%=a wall

1%=.9 degrees
1 degree=1.11111 percent

so a rover can do near enough to 55 degrees up and down and 36 degrees side slope.

Limiting factors for front/rear slopes being the lubrication factors and fuel pick up (with less than 1/4 in the small tank on a series you starve out at about 40 degrees) and side to side being the lateral traction and vehicle stability.

Most people hit the pucker factor long before they come anywhere near the limits of a rover.

To set the record straight .........

45 deg = 100% (1 in 1) ... i.e. (1/1)*100 = 100%
90 deg = infinity% (1 in 0) ... (1/0)*100 = infinity%
60% = 1 in 1.66667 = 31 deg
40% = 1 in 2.5 = 21 deg

Cheers

I am pretty much of the opinion that transmission mounted handbrakes are rubbish anyway (ducks for cover expecting hurled abuse, etc ).

Just put a Rover in a steep hill cross axle situation and see if the handbrake will hold it there. The front and rear differential action will allow the vehicle to move down hill without the propshafts turning at all.

My preference is for the handbrake to work directly on the rear wheels, that way you know that they will not turn. Given that in this situation the CDL will be locked (won't it?), then the front propshaft can't turn and the front wheels will also aid the brake operation.

Now I will sit back and wait for the comments...

Originally Posted by cewilson

This has been an interesting conversation. But in all seriousness, what we are talking about is some pretty damn advanced four wheel driving as a rule. It is beyond what most people would do with their family in the car

Hey,we are Landy(and Rangey),not Pajero owners,are we not?? Thats precisely why we have one for a family car.The family can always get out for the really tricky bits.For my two cents,I only ever use the foot brake(lightly,and carefully of course)if the old girl is getting away from me.Dunno about the handbrake,I was told by the dealer(not saying he'd know but) to never apply the handbrake when moving.If you can though,it makes sense to me that applying braking force to the drivetrain,would have less chance of locking up a wheel.

Originally Posted by Blknight.aus

so far landrovers work on 60% approach/depart and 40% side I think it even holds for a Freelander.

0 degrees=0%=flat ground
90 degrees=100%=a wall

1%=.9 degrees
1 degree=1.11111 percent

so a rover can do near enough to 55 degrees up and down and 36 degrees side slope.

Limiting factors for front/rear slopes being the lubrication factors and fuel pick up (with less than 1/4 in the small tank on a series you starve out at about 40 degrees) and side to side being the lateral traction and vehicle stability.

Most people hit the pucker factor long before they come anywhere near the limits of a rover.

I watched a pommie driver training video and the instructor was taking students along a side slope of 40 degrees saying that most would flinch at a lot less than this, he was driving a S1 Disco (ex camel trophy).

This a great disscusion, personnally i've never used the handbrake to slow my decents, mainly because i couldn't handle the whinging when she got back in the car

Baz.

Originally Posted by Redback

This a great disscusion, personnally i've never used the handbrake to slow my decents, mainly because i couldn't handle the whinging when she got back in the car

Baz.

I'll pay that one Baz, very good.

I personally havent used the park brake for slowing on steep slopes, i use the foot brake in moderation, to wipe speed off by periodically applying it. Matt

Originally Posted by drivesafe

This is one of those subjects that can have many arguments, both for and against, but which ever way you look at it, it is most definitely an education.

Prior to this thread starting, I personally would never have contemplated using my hand break in the way described but when you read how correct use can be a life saver in worst case scenarios, like that which Incisor found himself, it has to make you rethink the whole additional potential safety advantage this operation can give.

I for one would like to see ( and experiment myself ) the use of the hand brake in a controlled situation. Any ideas on how this could be done?

Again, anyone with a D3 or RRS, DO NOT try this. The electronically activated park break does not operate in the same manor as a conventional hand break.

Cheers

We teach this technique regularly at the LROC (Sydney Bch) training weekends. But I guess we are a bit far from the Gold Coast for you to attend!!
Therefore, for all those who wish to try this method, I submit the following detailed procedure:-


Automatic

Automatic 4WD’s do not stall in gear so normal stall recovery techniques do not apply.
Some automatic 4WD’s do not have a transfer case diff lock but do have a viscus coupling traction aid or rely on hill descent control.
With the following technique, total control is maintained at all times as easing off the accelerator will immediately slow the vehicle due to the constant action of the handbrake which, being a transmission brake is acting through all four wheels.
· Select low range and select drive to ascend the slope
· Forward momentum ceases due to lack of traction
· Back off accelerator completely
· Place foot on foot brake
· Apply the handbrake fully, take a breath and assess situation and your options
· Keeping foot on brake, select reverse gear
· Do not release handbrake
· Gently ease foot off brake. Vehicle should not move
· Gently accelerate the motor until the engine drives the vehicle to overcome the handbrake resistance
· Reverse the vehicle in this mode until the vehicle is facing the right direction or has moved to a location where traction has been resumed. It is now safe to descend normally
· Place foot on foot brake, at the same time release the handbrake
· Descend slowly using cadence braking technique, if required
· Do not lock up wheels
· When vehicle is safely at the bottom, ask yourself ‘do I need to ascend this slope?” If yes engage ‘drive’ and apply more revs if appropriate
· Improve traction – Wheel spin may be reduced by slightly decelerating and turning the steering wheel repeatedly from side to side. This may help to regain traction on loose surfaces.

NOTE:
If this technique of driving ‘through’ the hand brake is not used, then an automatic vehicle will run away initially and descend faster than is desired or safe. This is due to the initial take up of slack in the torque converter and higher gearing in automatics than manual vehicles.

Hope this is of some assistance in understanding the technique and also in practising it.

Roger

Hi Xtreme, thanks for that info.

I’ll have to give it a go and soon. That’s a good excuse to go for a bit of off roading.

Cheers.

i have just the spot for you to do it too tim ! :P