HDC query

The TC is monitored all the time but only activates to stop spinning wheels if they spin.

HDC works the same on an auto as a manual. It only works when in first or reverse gear as long as yer feet are oft the pedals. If an auto then the lever has to be pulled fully back to position 1, and not D in first gear. HDC is for limiting speed to stop you going too fast downhill. It will work on level ground but once it's slowed you down (if needed) tick-over won't make you go fast enough for it to activate again. If you put your foot on the brake or accelerator it will stop working. Take yer foot oft and it will operate if it needs to reduce yer speed.

Both TC and HDC are disabled if the brake system overheats. The ABS does a theoretical calculation and shuts oft TC and HDC if it thinks the brakes are too hot.

Skinny Mike said:

The hdc will not go over 5 mph that's why the brakes engaged and made noises.
It also works great uphill if on ice/snow. And on levelish ground if in deep mud or on a pebble beach etc. In fact if you get stuck just switch it on and engage first, it's never failed to pull me out of what I'm stuck in yet.
Cheers
Mike

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Hill Descent Control applies the brakes to keep the car at 5.6mph, afaik it doesn't work on the level or going uphill.

Wow my car must be really special. I put it in position 1 press hdc don't touch anything but the steering wheel and it never goes over 5 mph, brakes on level ground, drags its ass out of mud all on its own. Think I'll put it on eBay ' Undiscovered Landrover test vehicle for people with no legs'
Think I'll put a reserve of £20 on though!

Skinny Mike said:

Wow my car must be really special. I put it in position 1 press hdc don't touch anything but the steering wheel and it never goes over 5 mph, brakes on level ground, drags its ass out of mud all on its own. Think I'll put it on eBay ' Undiscovered Landrover test vehicle for people with no legs'
Think I'll put a reserve of £20 on though!

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to be fair it would do that if you did it without hdc engaged

Freelaner said:

mine makes a right racket when in hdc and always has, i'd assumed that is was a normal feature. sounds like a gear type rattly sound.

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that is your arse making that noise,just in case it might break down.again.

Freelaner said:

to be fair it would do that if you did it without hdc engaged

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No, it just sits and sulks then goes wrong if I don't push buttons.

So is there any point to it?

Take your feet off the pedals and rather than the engine braking, the HDC will use the brakes to keep speed down - until its overheated the brakes and then you are left with just engine braking because the brakes are cooked.

Would it not be better to use engine braking and 'periodic/intermittent' manual braking with ABS assistance for a more reliable decent?

Without low-range the Freelander is difficult to stop going down steep decents, but isn't it better to have a reliable system to work with? ie You'll start the decent quicker but won't end up hurtling down to oblivion.

Anyway, I thought brakes were not to be used on a steep decent - or does ABS mean its OK to do it these days?

The hdc uses the brakes to maintain a steady rate of descent by monitoring the wheel speeds and the use of a motion sensor. If you use the brakes yourself there is a good chance you will lock up. ABS helps but doesn't use the sensor that the HDC does.... So you could potentially have all 4 wheels locked and then slide down the hill.

If you don't have HDC on a freelander you don't have ABS so best not braking, use the low gear engine braking routine that is normally recommended.

It must be a very long hill for the HDC to overheat the brakes. I have never had a problem yet.

Learn to trust it. It works....... Well mine does anyway.

Epicuser said:

It must be a very long hill for the HDC to overheat the brakes. I have never had a problem yet.

Learn to trust it. It works....... Well mine does anyway.

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That's a whole new thread, who's HDC actually works!
Mine does, but as discussed, in a bit of an odd way.
Mike

Ive braked on snow/ice going down hill, the abs kicks in and keeps you going in a straight line. With out the abs going down same hill you get all side ways as you lockup (3 Amigos mode), you can straighten up again by releasing the brake momentarily. ...you are now the abs never tired hdc to be honest but I pressume its just auto abs????? I wonder if the abs fades out if your using the brake a lot and activating abs all the time......just because the brakes are getting hot, should not mean they fade out.....otherwise I'd have no brakes..

jedi said:

Ive braked on snow/ice going down hill, the abs kicks in and keeps you going in a straight line. With out the abs going down same hill you get all side ways as you lockup (3 Amigos mode), you can straighten up again by releasing the brake momentarily. ...you are now the abs never tired hdc to be honest but I pressume its just auto abs????? I wonder if the abs fades out if your using the brake a lot and activating abs all the time......just because the brakes are getting hot, should not mean they fade out.....otherwise I'd have no brakes..

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When brakes get very hot they stop working, I've had it happen on my old Disco 1 going down a long hill, luckily it happened near the bottom and it just coasted onto the flat! Learnt after that that its not just off roading where you need to consider engine braking more. Sat there for an hour and they were back to working again. Its happened to a mate with a Rangie as well.

GrumpyGel said:

When brakes get very hot they stop working, I've had it happen on my old Disco 1 going down a long hill, luckily it happened near the bottom and it just coasted onto the flat! Learnt after that that its not just off roading where you need to consider engine braking more. Sat there for an hour and they were back to working again. Its happened to a mate with a Rangie as well.

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Drum brakes do that. Discs get better when warm, and if you have ceramic pads the hotter the better

Maybe your brake fluid boiled.....?

One thing I do know. After the HDC has faded out because it thinks the brakes are overheated. They aren't. I tested mine last year. After the HDC stopped working, I stopped the car and measured the front brake discs. They were showing under 150° C. Which isn't hot at all for a brake disc.
The system definitely plays safe.

HDC pulses the brakes as required. There is a need for HDC. It stops yer Freelander going to fast downhill. Engine braking and low gear is already involved in the process. Covering the brakes going downhill is ok if you do it right. With experience you will be ok. If your going way too fast to start with then yer need to think about not going too fast instead. It's one thing having these systems but you can't rely on it correcting stoooopid mistakes or bad driving.

^^^^ wot he says

Skinny Mike said:

The hdc will not go over 5 mph that's why the brakes engaged and made noises.
It also works great uphill if on ice/snow. And on levelish ground if in deep mud or on a pebble beach etc. In fact if you get stuck just switch it on and engage first, it's never failed to pull me out of what I'm stuck in yet.
Cheers
Mike

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Skinny Mike said:

That's a whole new thread, who's HDC actually works!
Mine does, but as discussed, in a bit of an odd way.
Mike

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Unfortunately you have mixed up what TC and HDC do. TC stops spinning wheels by abs pulse braking spinning wheels to put the power into the wheels with grip. HDC is a speed limiting device only. It reduces speed if the speed is above the preferred limit, HDC is enabled, yer in 1st or reverse gear with yer feet oft the pedals. On the flat it will only slow you down if yer above speed, once. Once below speed you'll never go above the set limit on tickover alone. Tickover isn't that fast in a manual or auto so won't make you go fast enough for HDC to activate a second time, unless you accelerate then take yer foot oft or start going down a hill. HDC can pulse brake wheels individually to help to slow yer Freelander down and also gain control of skidding wheels.

Regarding uphill and ruts etc, yer mixing up what TC does. Even with HDC enabled in 1st gear... The TC is there to stop spinning wheels. Like when yer cross axled. Your TC and HDC works the same way as other Freelanders 1's do, and is no different. It's more a misunderstanding of what each systems does, and when it activates. Up hill you will have to apply power as tickover won't get you up. Hence HDC will be disabled regardless of you selecting it as yer feet are on the pedals. When yer feet are on either the brake or accelerator HDC is disabled even though you may have selected it. If you feel the ABS kick in up hill then this is the ABS controlled by the TC due to a spinning wheel, not HDC using the ABS. Same on an auto or manual.