New brake MC leaking - thoughts? (1 Viewer)

RWBeringer4x4

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Hey everyone,

Just got done my disc conversion using FJ60 knuckles on the front and Poser's kit in the rear. However, my new, NAPA rebuilt brake master cylinder (also 60-series) started leaking from the front "reservoir" (where the hose connects, under the rubber cap). There is a snap ring holding the tube in, and I believe an o-ring under the tube. I'm guessing this oring isn't seated properly?

My question is, before I dig in, does anyone know how it SHOULD be seated? Any other potential causes of this?

If I have to bleed the whole system again, I'd rather only do it once.... Thanks!

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RWBeringer4x4

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Unfortunately I bought it months ago, doubt they would take it...I guess I could turn it in as a core...

Seems like it might be easier to fix what I've got - replace the o-ring...
 
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I'm on my 2nd leaky Napa rebuilt clutch master in 2 years and about 2000 miles. If you haven't used it, and you have a receipt, a couple months should not matter. Their competitors offer lifetime warranty in many cases.
 
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I have pulled that little assembly on the rig to re-seat seal. Take a turkey baster or vacuum pump and pull brake fluid out of the reservoir just below the hose prior to pulling. No need to bleed system (at least I didn't have to) after reseal and top off.
 

RWBeringer4x4

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@firestopper - just so I'm not going in completely blindsided when I get in there, how does that seal seat? Down in the casting/reservoir or over the pipe running into it? what's the best way to get it to lay down and stay put?

I guess if firestopper's reseat suggestion doesn't work out, I'll bring it back to NAPA...if I can find the receipt...
 

RWBeringer4x4

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I ordered a replacement O-ring from Toyota for the MC. I had a couple of other things I needed to order, and the O-ring was fairly cheap, so why not give it a try? I'll try @firestopper 's approach first and if it still leaks, and I can find my receipt, I'll return it.

In the meantime, does anyone have a suggestion or intel on how this O-ring seats? is it sandwiched by the tube and "pressed" into the cylinder housing, or does it wrap around the end of the tube?

Obviously whatever is going on inside mine may not be the best example...
 
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RWBeringer4x4,
It been over a year and I can't remember what I had for lunch today haha, but if I recall the housing (cast part) has a groove for the o-ring type seal. Once you remove it it should be straight forward. you'll need to press the plastic portion in straight and lube the o-ring with brake fluid. make sure you "seat" it all the way and "witness" the groove for the snap ring on the top of cast housing . You should feel it seat if done right, avoiding rolling the o-ring from its groove.
Good luck.
 

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