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Flushing DOT 5 Fluid

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davidk

davidk

Jedi Trainee
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I have been using DOT 5 brake fluid in my clutch and brakes. I'm putting in a QuarterMaster hydraulic throw out bearing as part of the HVDA Toyota transmission switch. I've had very good success with the DOT 5, but the instructions say don't use it, use DOT 4. Even the QuarterMaster web site says don't use DOT 5. So, is there a good method for flushing out the DOT 5? I'm planning on taking the master apart, but what can I use to flush out the line? Anyone used DOT 5 in a QM throwout bearing?
Thanks for your help!
 
Aloha David,

I would think you could use the same method used to flush DOT 3 or 4 to get ready to switch to DOT 5. Use a compressor or gravity to drain the brake fluid through the bleeders and then alcohol as a final cleaning agent. The alcohol should dilute and flush and residue of the DOT 5 and any alcohol left should evaporate. A blast of compressed air should finish cleaning the lines.
 
I agree with Dave but I would recommend an "off car" test first. Try mixing some of the DOT-5 fluid with the alcohol on the bench before pouring some in the master cylinder. If they don't mix you'll need to keep looking for a better method.
 
You can still use the DOT5 for the brakes. So the only flushing is for the clutch reservoir/m/c through to the pipes. With the HVDA you don't use the slave cyl either. If it was mine, I'd pull the master and rebuild it with a new kit and flush the pipes with isopropyl alcohol.

Mine has a McLeod t/o that also doesn't like DOT5 so I use Castrol GT LMA - I guess Herman now uses Quartermaster?
 
dklawson said:
If they don't mix you'll need to keep looking for a better method.
Click to expand...
That's my guess as to what will happen. You may have to resort to a purpose-made solvent, like Acryli-Clean.

Or, since Hermsn's TOB supposedly uses only standard size O-rings for the seals; another route might be to change to silicone-compatible O-rings and continue using DOT 5.
 
As I recall Dot 5 is not soluable in alcohol - so a test is definately recommended.
 
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