Brake fluid change

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MikeyG
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Brake fluid change

Post by MikeyG » Thu May 16, 2019 9:35 pm

Hey guys,

So I'm guessing the brake fluid in the car hasn't been changed for about 20 years(!!). Its recommended dot 3, however, am I best putting dot 5.1 in purely because its "newer"? I've tried googling it a lot and cant find any good information. I just drive it normally.

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jrh
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Re: Brake fluid change

Post by jrh » Fri May 17, 2019 8:00 am

Be careful there.
What was good enough 20 years ago has lasted 20 years.
The 'modern' stuff can contain ingredients which are not compatible with the 'old' components in the system.

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Scooby
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Re: Brake fluid change

Post by Scooby » Fri May 17, 2019 10:24 am

DOT 3, 4, and 5.1 fluids are found in most brake and clutch systems. DOT 5 is a silicone oil based fluid and can only be used in new, dry systems.

In short, you can put DOT 4 in place of DOT 3 but not the other way around.

DOT 5 is not compatible with DOT 3 and 4 systems.

*Apparently, according to my tame mechanic.
Location: Banks, Nr Preston, Lancs.
Drives: 2x 24V - Japha and Chewie
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MikeyG
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Re: Brake fluid change

Post by MikeyG » Fri May 17, 2019 11:39 am

jrh wrote:
Fri May 17, 2019 8:00 am
Be careful there.
What was good enough 20 years ago has lasted 20 years.
The 'modern' stuff can contain ingredients which are not compatible with the 'old' components in the system.
I appreciate that, but I've dipped it with a tester pen and its showing atleast 4% water (the highest reading on the device). I guess its best to change it with DOT 3 to maximise compatibility?

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mojo98
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Re: Brake fluid change

Post by mojo98 » Fri May 17, 2019 12:48 pm

I`ve always used DOT 4, that what the hand book says

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Andy W
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Re: Brake fluid change

Post by Andy W » Fri May 17, 2019 12:52 pm

mojo98 wrote:
Fri May 17, 2019 12:48 pm
I`ve always used DOT 4, that what the hand book says
That's what I thought. I know we aren't able to use silicone fluid which is a shame as it isn't hygroscopic.

Kit
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Re: Brake fluid change

Post by Kit » Fri May 17, 2019 1:23 pm

Been changing my brake fluid on my cars later,
The old stuff was black, you can see the difference .
Don’t forget to do the clutch ;)

Kit

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