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Leamreject



Member Since: 19 Dec 2020
Location: Middle Earth - Leamington Spa
Posts: 950

Italy 2011 Defender 90 Puma 2.4 HT Fuji White
Personally I would avoid it unless you use your vehicle in extremely wet conditions. it may be better if you get it on your paint but it doesn’t perform as well and can’t be mixed with any other break fluid types.

There is a lot of online advice on differences, some good some subjective, but I would google it before you do.

One thing that may help you is that no performance team in any racing series uses dot5 currently, which speaks for itself it can change viscosity in extreme pressure systems which includes some ABS pumps (and this is bad news in a brake system) Ride like you stole it!!
If I’m not on a bike it’s because only a 4x4 will do…
2011 2.4 Puma 90 HT
Post #904509 23rd May 2021 6:50am
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Dinnu



Member Since: 24 Dec 2019
Location: Lija
Posts: 3141

Malta 2012 Defender 90 Puma 2.2 CSW Santorini Black
Yes, I read that dot5 and ABS do not go well together because dot5 can can aerate when the anti-lock brake system is activated. That can give you the spongy pedal feel. Not good.
But my old 90 has no ABS, so that would not be an issue.

There are also claims that dot5 is more compressible. I was always taught that all liquids are incompressible.... but even if it really was, perhaps it can be compensated for with braided brake lines!

Most of the reading I have done is on mountain bikes, where some users have switched from dot5.1 to dot5 without issues.
Perhaps there are a lot of myths out there, and of course car manufactures who tested their vehicles on dot3 will not tell you that dot5 will work as good. 1988 90 Hard Top, 19J Diesel Turbo, Shire Blue - Restoration ongoing
2012 90 CSW, 2.2TDCI, Santorini Black
Post #904534 23rd May 2021 10:22am
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Mo Murphy



Member Since: 01 Jun 2008
Location: Letchworth Garden City, Herts
Posts: 2062

United Kingdom 1984 Defender 90 200 Tdi HT Pennine Grey
Doesn't DOT5 rot rubber seals ?
Mo The Land Rover 90 - Many are called, few are chosen.
Post #904549 23rd May 2021 1:10pm
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Dinnu



Member Since: 24 Dec 2019
Location: Lija
Posts: 3141

Malta 2012 Defender 90 Puma 2.2 CSW Santorini Black
Apparently rubber seals can swell a little, which can be a positive thing as the seals will seal better.
Seems that need to keep away from silicone seals with Dot5. Silicone seals with silicone fluid is not ok. 1988 90 Hard Top, 19J Diesel Turbo, Shire Blue - Restoration ongoing
2012 90 CSW, 2.2TDCI, Santorini Black
Post #904564 23rd May 2021 4:56pm
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90 Dreamer



Member Since: 13 Jul 2019
Location: Oop North
Posts: 2045

United Kingdom 2016 Defender 90 Puma 2.2 HT Corris Grey
Dinnu wrote:
Yes, I read that dot5 and ABS do not go well together because dot5 can can aerate when the anti-lock brake system is activated. That can give you the spongy pedal feel. Not good.
But my old 90 has no ABS, so that would not be an issue.

There are also claims that dot5 is more compressible. I was always taught that all liquids are incompressible.... but even if it really was, perhaps it can be compensated for with braided brake lines!

Most of the reading I have done is on mountain bikes, where some users have switched from dot5.1 to dot5 without issues.
Perhaps there are a lot of myths out there, and of course car manufactures who tested their vehicles on dot3 will not tell you that dot5 will work as good.


Its more compressible because it does not absorb moisture and hence when the temps rise the water turns to gas and suddenly no brakes..........
Its not in common use for a very simple reason, it has BIG issues day to day
Post #904579 23rd May 2021 6:31pm
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Dinnu



Member Since: 24 Dec 2019
Location: Lija
Posts: 3141

Malta 2012 Defender 90 Puma 2.2 CSW Santorini Black
I get exactly what you mean 90 Dreamer. I should measure caliper temperature for my use. I do not want to do anything stupid that would regret later. I will find some day and push the Puma a bit hard, and measure that, although unsure if that is representative as there are quite some differences in the braking system, vented, larger pistons but more mass to stop. 1988 90 Hard Top, 19J Diesel Turbo, Shire Blue - Restoration ongoing
2012 90 CSW, 2.2TDCI, Santorini Black
Post #904714 24th May 2021 2:20pm
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Dinnu



Member Since: 24 Dec 2019
Location: Lija
Posts: 3141

Malta 2012 Defender 90 Puma 2.2 CSW Santorini Black
Did a few runs in my 90, ambient temperature 20dC. Front brake calipers just slightly warm to the touch. Rear calipers cold.
Perhaps did not push the brakes hard, but I checked on a trip when I was mostly going downhill. So I guess dot5 is perfectly fine for my use.
So I ordered 1 liter of dot5. Was not easy to find locally, some so called agents do not even know what dot 5 is. Always got offered 5.1. Perhaps 0.1 is insignificant, right? Rolling with laughter

It is bloody expensive liquid. 1988 90 Hard Top, 19J Diesel Turbo, Shire Blue - Restoration ongoing
2012 90 CSW, 2.2TDCI, Santorini Black
Post #906192 2nd Jun 2021 6:34pm
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90 Dreamer



Member Since: 13 Jul 2019
Location: Oop North
Posts: 2045

United Kingdom 2016 Defender 90 Puma 2.2 HT Corris Grey
Dot5.1 is NOT any relation to dot5

It shares its background wth dot 3 & dot4 which will all mix and was originally developed specifically for certain ABS applications - it would have been a far better option IMO
Post #906207 2nd Jun 2021 7:56pm
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Dinnu



Member Since: 24 Dec 2019
Location: Lija
Posts: 3141

Malta 2012 Defender 90 Puma 2.2 CSW Santorini Black
Yes, I am sure the other brake fluids are better performance wise. Just do not want to cry over spilt brake fluid (or leaky cylinders). Too many hours spent cleaning and painting. With dot3 or 4 I used to get a bit of white paste, better known as aluminium oxide on the cylinders from lack of use. Hence want to try dot5. Will be the first time for me.



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 1988 90 Hard Top, 19J Diesel Turbo, Shire Blue - Restoration ongoing
2012 90 CSW, 2.2TDCI, Santorini Black
Post #906213 2nd Jun 2021 8:19pm
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