Wrong brake fluid

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Location
New Orleans
#1
About 5 days ago I went on a little trip with my car and the brakes were feeling sluggish, I had to push on them relatively hard for the car to brake. I pulled over to a gas station and all they had was dot 3 brake fluid, so I bought it and put about 6 oz in the reservoir. I know that my car should use dot 4 synthetic fluid, will having the dot 3 mixed in damage my brake system? Will I need to bleed the whole system and fill it with dot 4? Thanks in advance,
Brian.
 
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Location
Bay Of Islands, NZ
#2
My understanding is DOT 3 has a lower boiling point, so under hard braking you may find it bubbles and causes air in your system.

Why not use it as an excuse to flush out your brake system? Use the remaining DOT 3 to flush, and then buy some nice new dot 4 to finish.
 
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Location
North East Illinois.
#3
My understanding is DOT 3 has a lower boiling point, so under hard braking you may find it bubbles and causes air in your system.

Why not use it as an excuse to flush out your brake system? Use the remaining DOT 3 to flush, and then buy some nice new dot 4 to finish.
Mixing the two may affect temp rating resulting in air(sluggish) problems.I agree flush the sysytem and refill with OEM.
 
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Location
Australia
#4
I disagree, Mixing the Dot 3 and 4 will have no adverse affects to your cars braking system.

I'm using a full system of Dot 3 fluid, and, as this is only a street car (not racing) have no problems what so ever. "6 oz," Or around 180 ml (for us metric folk) is alittle excessive. Expect a leak maybe? Keep a close eye on your brake fluid level dude!
 
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Location
Reading,PA
#5
I'm with Doughnut. The only difference is that DOT 4 has an additive to raise the boiling point. You basically now have DOT 3.5 LOL!

With that said, it IS important not to mix DOT 5 with older fluids. DOT 5 is substantially different (silicone based) and is reported to cause "gumming" problems when mixed.
 


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