Brake Fluid

hmmm

Member
I use Delphi Ultra Dot 5.1 fluid.

Some have higher boiling points than others.

I think Motul racing fluid is a good one.
 
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Shaun

New Member
Correct me if i'm wrong,but isnt 5.1 silicone fluid?If so i'm sure i've read that this doesnt lubricate any of the moving parts and therefore increases premature wear.
 

hmmm

Member
Shaun said:
Correct me if i'm wrong,but isnt 5.1 silicone fluid?If so i'm sure i've read that this doesnt lubricate any of the moving parts and therefore increases premature wear.

I think Dot 5 is the Silicone one.
 

youngsyp

Active Member
Shaun said:
Correct me if i'm wrong,but isnt 5.1 silicone fluid?If so i'm sure i've read that this doesnt lubricate any of the moving parts and therefore increases premature wear.
As above, DOT 5 is silicon fluid. DOT 5.1 is a mineral based fluid, specifically designed for ABS systems !

As Fast Guy has already said, about 1 litre should do you. Once you've used it, if there's any left in the bottle, you may as well bin it. This is because brake fluid is 'hydroscopic' meaning it absorbs moisture. As soon as it has contact with air, for any length of time, it will absorb any moisture it can. This will effectively lower the boiling point of the fluid considerably and can cause 'spongy' brakes.

Brake fluid is also a very good paint stripper so, keep it away from the body work or your wheels !

Depending on how hard you used the brakes, get the highest boiling point fluid you can buy, in a DOT 4 or 5.1 specification !
 

hmmm

Member
The highest boiling point fluid I found were Motul RBF 600 Racing Fluid or Millers Racing Brake Fluid 300 Plus.
 
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A

ale

Guest
i've been using 5.1 in my R for the last 2 years with no problems whether it be silicone based or not!
 
Hi,

My R is a non ABS model, so can I use dot 5.1?

I remember reading somewhere saying if you mix to different grades then it will turn to jelly? is this right?

Cheers,

Gaz
 

hmmm

Member
I think Dot 5.1 will mix with anything and won't turn to jelly. But it's definately better to flush the system and replace the whole fluid.
 

Fast Guy

Moderators
Staff member
Dot 5 is the one that shouldn't be mixed with anything.

Dot 5.1 should have realy been called Dot4.1 as it's an upgrade to Dot4 and nothing like Dot5
 
stupid question, how do i know whats in it currently? or just put 5.1 in?

Its never been changed since i had it imported.

Am i right in thinking flushing the system is pump pedal with a nipple undone, keep topping up reservoir until it runs clear from nipple. then repeat for other 3.

Ta

Gaz
 

Fast Guy

Moderators
Staff member
Flushing is a continuos bleed, so you need to close the nipple before you release the pedal to stop air going back up the system. Keep the reservoir topped up, so ou don't let air in at that end.

As to what's in it now, depend on what your car has been used for. It's very unlikely to be Dot5, unless the car has been a dedicated race car.
It could well be dot5.1 already, but possibly dot4 if the car is standard.
 

faz

New Member
This may sound stupid but is there any way to bleed your brakes yourself? I mean without having someone there to press the pedal for you?

And when upgrading brakes is it best to upgrade to braided hoses or do the standard ones still cope? (Upgrade to 4 pots)
 

Fast Guy

Moderators
Staff member
You can get one man bleed kits.

Fit braided hoses if you can. Make sure they have the locator to go on the damper as a couple of people have had the older hoses blow as they're not secured and have rubbed through on the wheel or whatever.:shock:
 
How about if I take a sample out of the reservoir and mix it with some 4 or 5.1 if it says fluid like then it should be fine? if it reacts then its dot 5?

Cheers for the help,

Gaz
 
A

ale

Guest
it doesn't mater about being abs or not it is only to do with the boiling point of the fluid but i would suggest changing it all for one grade and not to mix them! Ale.
 
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