![]() 07/09/2017 at 23:20 • Filed to: None | ![]() | ![]() |
If you ask me about mixing different weight oils or why biodiesel will eat the seals in your Mercedes or why switching from actual oil to synthetic is a bad idea, I have opinions based on folklore or stuff I read on oppo. Point being, changing from one type of fluid to another sometimes has unexpected consequences.
My brakes were a bit unpredictable this weekend which greatly slowed me down (confidence in your brakes helps). I had them high and firm and left the track with the pedal on the floor only to magically recover when the car cooled down.
So I’ve ordered new Hawk HPS pads all around and racing brake fluid.
So I know to flush the old fluid you basically bleed the brakes one at a time until you see fresh fluid. However, if I’m mixing DOT 3 and DOT 5.1 do I need to do anything magical other than the standard bleed process and seeing the color change to know that line is flushed?
![]() 07/09/2017 at 23:30 |
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Do you have ABS? Might have to cycle the pump to help flush the old fluid out of it.
![]() 07/09/2017 at 23:49 |
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I do. Kind of. Similar to how I have air conditioning. It is factory installed and both failed this weekend. I miss and will fix the AC.
I’ve no idea how to cycle the ABS pump but this is a very good homework assignment as it’ll help me understand what’s broken with the ABS so to avoid any surprises other than idiot lights for leaving it broken.
![]() 07/09/2017 at 23:58 |
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For some cars, I think you have to use some kind of scan tool to activate it. Otherwise, you might be able to get away with just slamming the brakes on gravel somewhere when nobody’s around, then re-bleeding the brakes again.
I’ve never had to switch from one type of brake fluid to another, but when I bled the old fluid out of my truck’s neglected system, it coughed up some nasty-looking stuff into the reservoir the very next time I used ABS.
![]() 07/10/2017 at 00:06 |
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The 1992 Corvette has an OBD 1 interface which no tool I’ve seen fits. To get the codes you short two pins and watch the dash. Electronic smoke signals, basically. Also seems dim witted in the way that I can clear my ABS and ASR (traction control) idiot lights by shutting down and firing right back up. The only parts of those systems working with any vigor is the warning lights tbh.
If/when ABS fires next after the change will have me hunting for debris after. Thanks.
![]() 07/10/2017 at 00:13 |
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Question: does the idiot light go off when someone else is driving?
![]() 07/10/2017 at 00:25 |
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You get a free pass as you’re helping me fix all this shit but token just the same.
![]() 07/10/2017 at 00:46 |
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5.1 is the silicon stuff, right? Pretty sure it’s non-reactive and should mix alright, although if you’ve bled everything to new fluid you’ll have gotten pretty well all of it out anyhow. Flushing the brakes is just done by bleeding a ton with fresh fluid.
![]() 07/10/2017 at 04:30 |
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5.1 is not silicon based. You’re thinking 5 without the .1 behind it. 5 is the only one not compatible with the others.
![]() 07/10/2017 at 05:22 |
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This 5 vs 5.1 question pops up way to often. Why the hell didn’t they just go to “6?”
![]() 07/10/2017 at 07:37 |
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Dot 3, 4 & 5.1 are mixable. Dot 5 is silicone based and will fuck up your shit
![]() 07/10/2017 at 10:40 |
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Or even 4.1? 5 is bound to be confusing.
![]() 07/10/2017 at 13:30 |
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What? I only get a
token
? Don’t you love
me any more?