DOT 4 expertise sought

[mtroxel]

9 year old A4 Q, I'm sure the brake fluid has never been flushed. Bought a liter of DOT 4 and will do this weekend.

In the past, I would spray some PB on the bleed nipples so they're ready this weekend. But reading about brake fluid, I see that the smallest amount of mineral oil can seriously deteriorate the DOT 4. Will I get some PB in contact with my DOT 4 and negate the purpose of flushing?

[Audibot]

Quite a long time. If they're going to give you an issue, you may want to consider replacing the bleed nipples. I've rarely had an issue, particularly when using the box portion of the wrench to crack it open/shut. Maybe just give it a good ol' wire brushing before starting?

[aluthman]

Helpful hint: Use brake fluid instead of PB blaster :-)

[billyhoyle]

Helpful hint: Use brake fluid instead of PB blaster :-)

This. It's actually quite good at breaking down corrosion. I liberally apply it to my motorcycle brake pistons to loosen them up when pulling them to rebuild calipers.

[mtroxel]

Helpful hint: Use brake fluid instead of PB blaster :-)

Nice. Thanks.

[vce1232000]

Helpful hint: Use brake fluid instead of PB blaster :-)
Good tip[up]. Just dont get any on paint[eek]. It will eat the [poop] out of it

[waiapasi2006]

9 year old A4 Q, I'm sure the brake fluid has never been flushed. Bought a liter of DOT 4 and will do this weekend.

In the past, I would spray some PB on the bleed nipples so they're ready this weekend. But reading about brake fluid, I see that the smallest amount of mineral oil can seriously deteriorate the DOT 4. Will I get some PB in contact with my DOT 4 and negate the purpose of flushing?
Use the motive bleeder system. It will safe you some time and mess. I've used it on 3 vehicles so far, and couldn't be happier.

[audihere06]

Good tip[up]. Just dont get any on paint[eek]. It will eat the [poop] out of it

I thought this too and when i got some on my paint I nearly cried but it didnt do anything to it. Dot 4 must be nowhere near as harsh as dot 3. I also spilled it on my painted garage floor and it seriously cleaned in but didn't remove the paint.


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[mtroxel]

Flushed it all out today. Used some DOT3 to loosen the bleeder valves (wanted to wait to open DOT4 when I had to). Did it work? No idea. One was very hard to loosen. Best fitting 11mm I had was a 6 pt socket for a 1/4" drive. Actually put a pipe over that little ratchet and held my breath.


I thought this too and when i got some on my paint I nearly cried but it didnt do anything to it.

Same here. Got some on the paint down under the brake booster (has no clear coat on it) and I can't see a bit of damage.