Bench bleeding creates leak at rear seal

1988 TOYOTA PICKUP
300,000 MILES • 2.4L • 4 CYL • 2WD • MANUAL
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PUMPKINTRUCK79
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On my third new master cylinder, and bench bleeding is causing the rear seal to leak on each one. any idea what I can be doing wrong?
Dec 11, 2020 at 4:15 PM
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ASEMASTER6371
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Good evening,

You are doing nothing wrong.

That seal should not leak at all. You need a different brand master cylinder.

https://www.2carpros.com/articles/how-to-replace-a-brake-master-cylinder

What brand master are you using?

Roy
Dec 11, 2020 at 4:29 PM
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PUMPKINTRUCK79
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Brakebest Select is the newest one from O'reilly's. Other 3 from Advance were remanufactured.
Dec 12, 2020 at 5:41 AM
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ASEMASTER6371
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I would get a better brand.

I attached a Raybestos from Rock Auto for you.

Roy
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Dec 12, 2020 at 5:46 AM