I accidently put it in dot3 instead of dot4

[iwantspeed]

Hey guys I made a mistake my brake/clutch reservoir was low I stopped at a gas station a purchased dot3 brake fluid instead of dot 4.:(

now my right rear brakes are now squeaking and the anti lock light came on for the first time for 5 seconds. That light has never come on since I have owned the car.

I have read some articles saying basically that you can add higher dot rating then recommended but never lower.

What should my next step be?

remove all the fluid in the reservoir with a turkey baster add dot 4 fluid and bleed the brakes?

This occurred on sat I drove it home and haven't moved it since.

Yes it was my mistake I don't need to be reminded of it. just need a solution.

[Kruzen]

Just flush it out with dot 4, dot 3 is just going to heat up quicker

[Liam]

Flush it well, DOT 3 is not compatible at all with the BMW hydraulic systems.

There my be something else going on as well like:

where did the fluid go? It doesn't evaporate.

Are the pads worn all the way down?

[iwantspeed]

before I added the brake fluid the brakes weren't squeaking at all
after I added the dot 3 they started squealing
and the pads are not worn down they are pretty fresh.

[Liam]

Just get that DOT3 out of there.

I don't think it would cause the pads to up and start to squeak but it will tear up the hydraulics.

[iwantspeed]

Liam

I lost fluid when I moved the line that goes to the clutch of the reservoir

http://www.e30tech.com/forum/showthread.php?t=69513

[jlevie]

DOT 3 fluid shouldn't be your problem. From Dave Zechausen (a brake guru):

"The DOT 2 spec is for drum brakes and is obsolete. If you have any DOT 2 in your garage, throw it away! DOT 5 is for silicone brake fluid. Silicone brake fluid (DOT 5) should be avoided because it is not compatible with regular brake fluid, it is hard to pour without introducing bubbles and thus results in soft pedal feel, and moisture still gets into your system and will pool in low areas like your calipers and encourage rapid corrosion. STAY AWAY!

That leaves DOT 3 and DOT 4 fluids. These fluids are compatible with each other and may be interchanged or mixed with no ill effects."

[slo325i]

wow, i've been using dot 3 for at least a year now w/o stopping or clutch problems.... maybe I should flush it and refill with dot 4....

[Alexor]

wow, i've been using dot 3 for at least a year now w/o stopping or clutch problems.... maybe I should flush it and refill with dot 4....

The only difference between Dot 3 and Dot 4 fluids are boiling points. Dot 4 can get hotter than Dot 3 before it bubbles.

[iwantspeed]

if dot 3 is fine it just has a higher boiling point why are poeple in this thread and it other threads saying that dot 3 will damage the hydraulic systems?

regardless if it does or doesn't I'm going to flush it out.

ok thanks

I'm going to flush it out soon.

[Alexor]

if dot 3 is fine it just has a higher boiling point why are poeple in this thread and it other threads saying that dot 3 will damage the hydraulic systems?

regardless if it does or doesn't I'm going to flush it out.

ok thanks

I'm going to flush it out soon.

I really don't know how it could damage the hydraulics. Maybe I'm stupid. Anybody?

I would think if anything you'd just get a squishy brake pedal from the fluid boiling and air getting in the lines, assuming you overheated the fluid.

However, I'm not arguing that Dot 3 is better. I just ordered ATE Super Blue brake fluid just because I'm replacing all brake lines and hoses and it'll make me feel better. :)

[Liam]

The only difference between Dot 3 and Dot 4 fluids are boiling points. Dot 4 can get hotter than Dot 3 before it bubbles.

DOT3 is different shit and will attack the soft parts in the hydraulic system.

This isn't an absolute truth though because some new DOT3s are compatible with the seals but I just wouldn't risk it anyway.

Important EDIT: Looked a bit farther into this, the DOT3 I'm talking about no longer exists as far as I have been able to ascertain all DOT3 manufactured today is compliant with LMA.

So I'm wrong here on it eating shit up.

[wolfgangstbd]

^^
beat me to it.. there are specific fluids to keep the seals and even some of the metal in there from swelling or drying out and cracking.. get it out!

[gearheadE30]

ATE Superblue

/thread

[iwantspeed]

are the bleeder screws on each caliper prone to cracking, when you break them free to bleed the brakes?