D3 TDV6 Brake fluid options

[LR3 Disco Owner]

Ok, so I've been doing some research into brake fluid options as I recently replaced all discs, pads, shoes and sensors. Hopefully next time I have to do that I'll have a flat concrete floor to work on!
Anyway, after compressing all the pistons in the process of replacing the pads I had to drain off the excess fluid and it is looking fairly dark. In a syringe it has a greeny yellow tinge to it, but once the appropriate amount had been squirted into another container for disposal it was looking rather dark and opaque, so now I've added changing the brake fluid to my list of things to do.
I read previous threads on here about the use of different fluids, mainly Penrite and the OEM Shell fluid. There was talk of the Penrite Super Dot 4 and their Dot 4 ESP as alternatives to the Shell Dot 4 ESL.
The sticking point seems to be the ISO 4925 Class 6 specification, as many of the others I looked at including Castrol, Bosch, Valvoline, Nulon, the own brand ones and even the Penrite Super Dot 4 don't have that specification, rather they seem to be Class 3 or 4.
On looking at the Penrite website, they now actually specify their Dot 5.1 fluid for the Disco 3 TDV6, so I had a look at the specifications for the different fluids to properly compare them and they are shown below:




Penrite Super Dot 4

Penrite Dot 5.1

Penrite Dot 4 ESP

Shell Dot 4 ESL



Density at 20°C, kg/L

1.069

1.067

1.055

1.058



Viscosity, Kinematic, cSt at -40°C

1147

690

700

716



Viscosity, Kinematic, cSt at 100°C

2.23

2.04

2.1

2.1



Equilibrium Reflux Boiling Point (wet)

183

184

165

181



Equilibrium Reflux Boiling Point (dry)

275

274

260

273



As you can see the specs confirm that the Super Dot 4 seems to be a slightly different beast and although they have the information for it, I found mention that the Dot 4 ESP has actually been discontinued.
So moving forward do people feel that the Dot 5.1 is a readily available alternative, and at $30 for 500ml how does it compare to the dealership prices, as I'm waiting to hear back from my nearest dealer? Is anyone already using it and what are peoples thoughts on using DOT 5.1 rather than 4, are there any downsides apart from the price?

[DiscoJeffster]

For this reason I just buy a litre from the dealer every few years and suck up the cost. I don’t recall it being that much.

In fact, I added it to one of my online orders from the UK - 1 litre, GBP 11.05.

[PerthDisco]

The Nulon Dot 4 in yellow bottle in SCA has the ISO 4925 rating that’s important. Only needs to be Dot 4 with that rating and no more complex.

[DiscoJeffster]

The Nulon Dot 4 in yellow bottle in SCA has the ISO 4925 rating that’s important. Only needs to be Dot 4 with that rating and no more complex.

Sorry that’s incorrect. It needs to be 4925 class 6 which is very different. 4925 is broken into many specs. It saying 4925 and not specifying the class is useless. I note the specs for viscosity on their documentation for that fluid do not make it class 6 viscosity compatible.

Penrite have their DOT4ESP which is up to class 6 compatible.

[LR3 Disco Owner]

And there's the kicker, ISO 4925 Class 6 states that the viscosity has to be at or below 750 whereas Class 4 is at or below 1800.
Now the ISO standard also says that Super DOT 4 should be Class 6, but both the Nulon and the Penrite don't meet the Class 6 specification with viscosities of 1231 and 1147 respectively, instead they just list that they meet ISO 4925 and don't mention the Class, could this be to deliberately mislead, as people would rightly assume that since it is Super DOT 4 that it should be Class 6?
I'd be interested to see a graph of the viscosity against temp to see how they compare at around 0 degrees as that's probably more applicable here than -40!

[DiscoJeffster]

And there's the kicker, ISO 4925 Class 6 states that the viscosity has to be at or below 750 whereas Class 4 is at or below 1800.
Now the ISO standard also says that Super DOT 4 should be Class 6, but both the Nulon and the Penrite don't meet the Class 6 specification with viscosities of 1231 and 1147 respectively, instead they just list that they meet ISO 4925 and don't mention the Class, could this be to deliberately mislead, as people would rightly assume that since it is Super DOT 4 that it should be Class 6?
I'd be interested to see a graph of the viscosity against temp to see how they compare at around 0 degrees as that's probably more applicable here than -40!

Exactly. I did the same research. They’re deliberately misleading in my opinion hence I just went with genuine, but there are alternatives such as the Penrite, if you can find it

[LR3 Disco Owner]

Penrite have their DOT4ESP which is up to class 6 compatible.

Unfortunately their website says they are discontinuing it and that the 5.1 is the replacement.

[BradC]

Penrite have their DOT4ESP which is up to class 6 compatible.

I used this for my last flush. Car hasn’t burst into flames and the abs still works. I still need to flush the clutch slave, but I keep putting that off.

The fluid that came out of the front calipers looked like mud.

[101RRS]

I just buy mine from a dealer - is the same cost as some after market fluid from Supercheap.

[PerthDisco]

Sorry that’s incorrect. It needs to be 4925 class 6 which is very different. 4925 is broken into many specs. It saying 4925 and not specifying the class is useless. I note the specs for viscosity on their documentation for that fluid do not make it class 6 viscosity compatible.

Penrite have their DOT4ESP which is up to class 6 compatible.

And I thought for the first time I found the correct part without several days of research! I scanned Bodsy’s Bible who does mention Class 6 but I just saw the bit where he says 4925 is important.

[LR3 Disco Owner]

I just buy mine from a dealer - is the same cost as some after market fluid from Supercheap.

Can you remember how much that was? As the DOT 5.1 is $30 a bottle I reckon the main dealer price can't be too far off that. My local Supercheap and Repco don't have any of the DOT 4 ESP in stock and the dealer is 180km round trip, so if I was just topping up I'd probably just go the 5.1 but since I'm going to flush it out based on other comments I'd need around 1.5L(??) which then warrants the drive.

[DiscoJeffster]

I just buy mine from a dealer - is the same cost as some after market fluid from Supercheap.

Yeah same. It’s just easier and not expensive.

[PerthDisco]

And there's the kicker, ISO 4925 Class 6 states that the viscosity has to be at or below 750 whereas Class 4 is at or below 1800.
Now the ISO standard also says that Super DOT 4 should be Class 6, but both the Nulon and the Penrite don't meet the Class 6 specification with viscosities of 1231 and 1147 respectively, instead they just list that they meet ISO 4925 and don't mention the Class, could this be to deliberately mislead, as people would rightly assume that since it is Super DOT 4 that it should be Class 6?
I'd be interested to see a graph of the viscosity against temp to see how they compare at around 0 degrees as that's probably more applicable here than -40!

So in the real world of Straya what will go wrong using Class 4 instead of 6?

[LR3 Disco Owner]

So in the real world of Straya what will go wrong using Class 4 instead of 6?

I don't know, that's the thing, saying the one is nearly twice as thick as the other at -40 degrees doesn't really mean much here, it would be more beneficial to know what the difference is at 0, or maybe -10 if you're going to the snow, but otherwise it comes down to how easily it travels through the braking system.

[DiscoJeffster]

So in the real world of Straya what will go wrong using Class 4 instead of 6?

The ABS system will operate slower and the traction will be less effective. Also supposedly it’s designed to protect new types of seals used in the system.

[DiscoJeffster]

Bosch claimed somewhere that the ABS cycle speeds were improved by over 30% using class 6 and it was developed to support traction control systems as used in the Disco etc.

[101RRS]

Can you remember how much that was? As the DOT 5.1 is $30 a bottle I reckon the main dealer price can't be too far off that. My local Supercheap and Repco don't have any of the DOT 4 ESP in stock and the dealer is 180km round trip, so if I was just topping up I'd probably just go the 5.1 but since I'm going to flush it out based on other comments I'd need around 1.5L(??) which then warrants the drive.

Its been a couple of years as I bought a few bottles to last me a while but was under $20 a litre bottle (Lennocks in Canberra). I ended up going to the dealer as the exact grade of oil was not available in stock at Repco/Supercheap/Shell etc and I would have to order it and of course I needed some right then and then.

[PerthDisco]

The ABS system will operate slower and the traction will be less effective. Also supposedly it’s designed to protect new types of seals used in the system.

Looks like I’ll be doing a double flush soon.

[BradC]

Unfortunately their website says they are discontinuing it and that the 5.1 is the replacement.

It is specified to meet the specs and the viscosity is right. Why wouldn’t you use it?

[DiscoJeffster]

It is specified to meet the specs and the viscosity is right. Why wouldn’t you use it?

Agree. It meets ISO 4925 class 6 so I would.

[PerthDisco]

I’d be a lot happier if like the TC LR had a generic container with home made label that said ‘Special Brake Fluid’ - makes me feel special every time I open one.

[DiscoJeffster]

I’d be a lot happier if like the TC LR had a generic container with home made label that said ‘Special Brake Fluid’ - makes me feel special every time I open one.

Hahahahaha

[LR3 Disco Owner]

Well Tony from LR in Wollongong got back to me today with a price of $40.15 for 1L of the genuine magical LR brake elixir and he reckons that's enough to do a flush with, and as he's the parts manager I'll take his word for it. Now to find time to drive down and get it.
On another related note, When I did the brakes I followed the procedure for adjusting the EPB and everything went fine, the hand brake holds on a reasonable incline, so it is working but during the bedding in process it took forever to stop at first and only got marginally better by the tenth application of the EPB, it certainly was nowhere near as effective as what I've seen demonstrated on youtube clips. So I guess my question is, is there any other adjustment that can be done and what happens if the cable is stretched, is that then a replace the EPB module situation?

[101RRS]

Well Tony from LR in Wollongong got back to me today with a price of $40.15 for 1L of the genuine magical LR brake elixir

Seems a bit high - have you tried anywhere else?

[LR3 Disco Owner]

Would different LR dealers have different prices? I haven't looked at any of the other aftermarket LR sites yet for the Shell fluid, just for the alternatives. I was thinking in comparison to the Penrite DOT 5.1 it was quite competitive![bigsmile1]

[josh.huber]

Would different LR dealers have different prices? I haven't looked at any of the other aftermarket LR sites yet for the Shell fluid, just for the alternatives. I was thinking in comparison to the Penrite DOT 5.1 it was quite competitive![bigsmile1]

Yeah the price is good. I bought 2 new rear rotors today. They were selling 250ml bottles for $10 each.

[rick130]

From my reading of the ISO 4925 Class 6 specs the differences only become apparent in near sub zero weather vs DOT 4 ISO 4925 Class 4 fluid, in normal lubricating oil terms a Class 6 fluid would have a higher viscosity index.

For most Australian ambient and vehicle operating temps there'll be no difference in ABS and TC performance.
And seeing as the ABS pump is in the engine bay it'd be interesting to put a thermocouple on one even in the Snowy's during winter just to see what it's operating temp would be.

If concerned just use a readily available DOT5.1 fluid and you'll have a slightly higher dry BP too.

I find it interesting that most blenders have a Super DOT4 fluid, I've used Castrol for years as that's what I always used in race cars and yet when reading the specs they only meet the Super DOT4 BP, not the low temp viscosity, eg Castrol React Performance DOT4 sits half way between the DOT4 and Super DOT4 -40* viscosity.

[PerthDisco]

From my reading of the ISO 4925 Class 6 specs the differences only become apparent in near sub zero weather vs DOT 4 ISO 4925 Class 4 fluid, in normal lubricating oil terms a Class 6 fluid would have a higher viscosity index.

For most Australian ambient and vehicle operating temps there'll be no difference in ABS and TC performance.
And seeing as the ABS pump is in the engine bay it'd be interesting to put a thermocouple on one even in the Snowy's during winter just to see what it's operating temp would be.

If concerned just use a readily available DOT5.1 fluid and you'll have a slightly higher dry BP too.

I find it interesting that most blenders have a Super DOT4 fluid, I've used Castrol for years as that's what I always used in race cars and yet when reading the specs they only meet the Super DOT4 BP, not the low temp viscosity, eg Castrol React Performance DOT4 sits half way between the DOT4 and Super DOT4 -40* viscosity.

I feel better already

It’s absolute water when pouring in. No viscosity whatsoever.

[rick130]

I feel better already

It’s absolute water when pouring in. No viscosity whatsoever.

Most all should be, they are only around 2cSt@100*, less than 1/3 the viscosity of a low vis ATF

[DieselLSE]

...they are only around 2cSt@100*
Gee, I love that kinda talk!