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TheWojtek



Member Since: 08 May 2015
Location: Poznań, Poland
Posts: 737

Poland 2010 Range Rover Sport TDV8 HSE Buckingham Blue

Don't get me started Rolling with laughter

Short story is exactly what RRSDV8 wrote. Braking is nothing more than converting kinetic energy to heat (still energy) by means of friction between the pads and discs. Regards etc.,

Wojtek

---
WAS: 2006 RRS Supercharged
IS: 2010 RRS TDV8 HSE

Post #633974 Tue Jun 27 2023 9:39pm
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RRSTDV8



Member Since: 12 Aug 2011
Location: Northamptonshire
Posts: 8988

United Kingdom 2012 Range Rover Sport SDV6 HSE Orkney Grey

Col wrote:
So you mean it's not the "energy" exerted from my right foot on to the brake pedal, through the hydraulic system to the caliper, which pushes the piston into contact with the brake pad which creates friction with the brake disc, which in turn slows the vehicle?

Cheers
Col

Ultimately, it's the creation of heat that slows the vehicle. The mechanism used to achieve that is irrelevant.

It could just as easily be a big wedge-shaped brake pad that is lightly flicked by your finger in to the gap between disc and calliper to then be forced by the disc's rotation to press on the disc itself. You would have expended a miniscule amount of energy to achieve the braking action. Your energy wouldn't be doing the work of slowing the vehicle.

Alternatively, one could drop an anchor off the back of the vehicle. Then the slowing would be caused by friction (heat) and also by the transfer of kinetic energy to bits of ground as they are thrown around (which would also be dissipated as heat by way of friction with the air and impacts with the ground / other bits of flying ground).

It would still be an increase in entropy either way. 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

Post #633975 Tue Jun 27 2023 10:25pm
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Col



Member Since: 02 Sep 2012
Location: Hawkes Bay NZ
Posts: 4982

New Zealand 2013 Range Rover Sport Supercharged Autobiography Santorini Black

If it's been a recent development with the brakes, I think I would still be inclined to change the brake fluid, you say you know it's been changed, but I have had mine done by a dealer before and it was the cleanest brake fluid change I have ever seen, and they only used one liter to completely flush the old out and bleed the system. I used nearly that amount to just fill the reservoir. Could try 5.1 as it does have a lower viscosity and a slightly higher temp. operating range than Dot4.

Cheers
Col

Post #633976 Tue Jun 27 2023 11:11pm
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RRSTDV8



Member Since: 12 Aug 2011
Location: Northamptonshire
Posts: 8988

United Kingdom 2012 Range Rover Sport SDV6 HSE Orkney Grey

I agree with Col and others. Change the fluid first and see where you are then. 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

Post #633977 Wed Jun 28 2023 7:28am
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BJH1959



Member Since: 25 Mar 2017
Location: Paredes de Coura, Portugal
Posts: 410

Portugal 2005 Range Rover Sport TDV6 HSE Cairns Blue

Thanks everyone. I will book it in to have the brake system checked and to have the brake fluid changed and replaced with DOT 5.1 LV.

I will update after it's been done and after I've driven it a bit to let you know how things are.

Thumbs Up Barrie.
2017-Jan 2024: 2005 RRS 2.7TDV6. Best car I ever had - until now!
Current: 2018 Ford Ranger Wildtrak 3.2

Post #633978 Wed Jun 28 2023 9:06am
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samd



Member Since: 21 Sep 2009
Location: Derbyshire
Posts: 125

England 

Col wrote:
So you mean it's not the "energy" exerted from my right foot on to the brake pedal, through the hydraulic system to the caliper, which pushes the piston into contact with the brake pad which creates friction with the brake disc, which in turn slows the vehicle?

Cheers
Col


...and, at my age, you can't discount the significant amount of energy required to even think about that action, in the first place!! Remembering which foot? 2017 3.0 SDV6 HSE

Post #633979 Wed Jun 28 2023 9:21am
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Col



Member Since: 02 Sep 2012
Location: Hawkes Bay NZ
Posts: 4982

New Zealand 2013 Range Rover Sport Supercharged Autobiography Santorini Black

If you do have a slight language barrier at times make sure they do realise it is Dot 5.1 and not Dot 5 or else you will be in trouble.

Cheers
Col

Post #633980 Wed Jun 28 2023 9:39am
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RRSTDV8



Member Since: 12 Aug 2011
Location: Northamptonshire
Posts: 8988

United Kingdom 2012 Range Rover Sport SDV6 HSE Orkney Grey

I'd be tempted to buy the right stuff and say "put that in". Thumbs Up 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

Post #633981 Wed Jun 28 2023 11:07am
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BJH1959



Member Since: 25 Mar 2017
Location: Paredes de Coura, Portugal
Posts: 410

Portugal 2005 Range Rover Sport TDV6 HSE Cairns Blue

OK... may well stick with the recommended DOT 4 then. Thumbs Up Barrie.
2017-Jan 2024: 2005 RRS 2.7TDV6. Best car I ever had - until now!
Current: 2018 Ford Ranger Wildtrak 3.2

Post #633986 Wed Jun 28 2023 1:42pm
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NoExpert



Member Since: 28 Jan 2022
Location: Poznań, Poland
Posts: 483

Poland 2011 Range Rover Sport 3.0 TDV6 HSE Lux Fuji White

Just be sure it’s DOT 4 LV. Plenty of options, I’m using Brembo stuff. Motul makes it as do a number of other reputable brands. Cost shouldn’t be much more than regular DOT 4. 2011 RRS HSE Luxury 3.0 TDV6 Fuji White on Ebony/Ivory
Born and raised in So Cal. Moved to the UK in 2018 for a few years. Now in Poland and looking at moving back to the UK.

Post #633990 Wed Jun 28 2023 4:41pm
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Col



Member Since: 02 Sep 2012
Location: Hawkes Bay NZ
Posts: 4982

New Zealand 2013 Range Rover Sport Supercharged Autobiography Santorini Black

So whats wrong with using Dot 5.1 fluid, it's a higher spec. fluid than Dot4 LV,it's a low viscosity fluid and totally compatible with Dot 4LV. I changed to it in my L320 S/C last time I changed the fluid which was a couple of years ago and certainly have no issues with the brakes.

Cheers
Col

Post #634013 Wed Jun 28 2023 9:40pm
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NoExpert



Member Since: 28 Jan 2022
Location: Poznań, Poland
Posts: 483

Poland 2011 Range Rover Sport 3.0 TDV6 HSE Lux Fuji White

It’s more hygroscopic than DOT 4 LV and should be changed more often. Other than that, nothing. BJH1959 said he may well stick with DOT 4, I was just reiterating it needs to be DOT 4 LV. If he or anyone else decides to run DOT 5.1 that’s up to them and will work fine in the system, just should be changed more often. 2011 RRS HSE Luxury 3.0 TDV6 Fuji White on Ebony/Ivory
Born and raised in So Cal. Moved to the UK in 2018 for a few years. Now in Poland and looking at moving back to the UK.

Post #634028 Thu Jun 29 2023 4:42am
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Col



Member Since: 02 Sep 2012
Location: Hawkes Bay NZ
Posts: 4982

New Zealand 2013 Range Rover Sport Supercharged Autobiography Santorini Black

No Expert, my response was not to you I was asking Barry why he was going to stick with Dot4 as opposed to the Dot5.1 which is higher spec fluid, however obviously what spec. fluid he choses to use in his own vehicle is entirely his choice.

Cheers
Col

Post #634031 Thu Jun 29 2023 7:10am
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BJH1959



Member Since: 25 Mar 2017
Location: Paredes de Coura, Portugal
Posts: 410

Portugal 2005 Range Rover Sport TDV6 HSE Cairns Blue

Thanks again to everyone for the info and advice.

I am still undecided as to whether to get DOT 4 LV or DOT 5.1 LV as there are clearly valid cases for using one or the other.

Considering everything I've seen and read here (and elsewhere) the issue seems very likely to be the quality of the fluid currently in the system.

On that basis I'll also see what the mechanics at the garage have to say about it now I have a starting point - for which I'm grateful to you all.

Thumbs Up Barrie.
2017-Jan 2024: 2005 RRS 2.7TDV6. Best car I ever had - until now!
Current: 2018 Ford Ranger Wildtrak 3.2

Post #634033 Thu Jun 29 2023 9:39am
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RRSTDV8



Member Since: 12 Aug 2011
Location: Northamptonshire
Posts: 8988

United Kingdom 2012 Range Rover Sport SDV6 HSE Orkney Grey

I'd use which ever you can most easily obtain. Either will do the job, so availability is the big factor. 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

Post #634042 Thu Jun 29 2023 3:15pm
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