Brake bleed valve seat....calling all brake gurus |
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Brake bleed valve seat....calling all brake gurus |
raynekat |
Nov 10 2018, 06:16 PM
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#1
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Advanced Member Group: Members Posts: 2,158 Joined: 30-December 14 From: Coeur d'Alene, Idaho Member No.: 18,263 Region Association: Pacific Northwest |
Just trying to get an answer over the weekend to a question I have.
I've got some new rear calipers going on the car and one of them is weeping some brake fluid. Hard to see exactly where it is coming from. Could be a bleeder valve or possibly a defect in the caliper casting. I have a question about the brake bleed nipple seat.....actually the very bottom where the end of the bleed valve bottoms out. See pic below: To me, the correct bottom of the bleed valve seat should be beveled to match the beveled point at the end of the bleed valve....such as the example on the right. My particular caliper has a seat bottom that is square like the example on the left. Not only do you get less surface area for the bleed valve to seat against possibly causing a leak even when the bleed valve is closed or tightened up....but if you tighten the bleed valve even a moderate amount, the square bottom will put a nice "step" in the bevel of your bleed valve. I don't believe that is an optimal situation or even wanted. Any thoughts or knowledge on this? I'm thinking I have an incorrectly machined bleed valve seat. I was thinking about taking a proper sized drill bit and putting a bevel down there, but the angle is not the same on the drill bit. On Monday I'll check with Eric at PMB for his take on this. |
raynekat |
Nov 11 2018, 01:59 PM
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#2
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Advanced Member Group: Members Posts: 2,158 Joined: 30-December 14 From: Coeur d'Alene, Idaho Member No.: 18,263 Region Association: Pacific Northwest |
The point on the bleeder valves is right at 90 deg.
Ordering a 3/16" countersink bit with a 90 deg tip to chamber a bit of that square seat on Ebay right now. I'll loan it out to anyone who wants to use it (hint hint wink wink Mark Heard). |
rgalla9146 |
Nov 11 2018, 03:49 PM
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#3
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Advanced Member Group: Members Posts: 4,555 Joined: 23-November 05 From: Paramus NJ Member No.: 5,176 Region Association: None |
The point on the bleeder valves is right at 90 deg. Ordering a 3/16" countersink bit with a 90 deg tip to chamber a bit of that square seat on Ebay right now. I'll loan it out to anyone who wants to use it (hint hint wink wink Mark Heard). This is not a job that should be trusted to a hand held tool. You'll be inviting a more difficult repair. Is this is quality control issue that the supplier might be best equipped o remedy ? |
raynekat |
Nov 11 2018, 05:19 PM
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#4
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Advanced Member Group: Members Posts: 2,158 Joined: 30-December 14 From: Coeur d'Alene, Idaho Member No.: 18,263 Region Association: Pacific Northwest |
The point on the bleeder valves is right at 90 deg. Ordering a 3/16" countersink bit with a 90 deg tip to chamber a bit of that square seat on Ebay right now. I'll loan it out to anyone who wants to use it (hint hint wink wink Mark Heard). This is not a job that should be trusted to a hand held tool. You'll be inviting a more difficult repair. Is this is quality control issue that the supplier might be best equipped o remedy ? I'll be attempting this with a drill press. Not sure it's that tough if you're careful. In my case....I've got nothing to lose really. Without a successful outcome, these calipers are going in the dumpster. |
sixnotfour |
Nov 11 2018, 05:36 PM
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#5
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914 Wizard Group: Members Posts: 10,432 Joined: 12-September 04 From: Life Elevated..planet UT. Member No.: 2,744 Region Association: Rocky Mountains |
The point on the bleeder valves is right at 90 deg. Ordering a 3/16" countersink bit with a 90 deg tip to chamber a bit of that square seat on Ebay right now. I'll loan it out to anyone who wants to use it (hint hint wink wink Mark Heard). This is not a job that should be trusted to a hand held tool. You'll be inviting a more difficult repair. Is this is quality control issue that the supplier might be best equipped o remedy ? I'll be attempting this with a drill press. Not sure it's that tough if you're careful. In my case....I've got nothing to lose really. Without a successful outcome, these calipers are going in the dumpster. If you get it square inline to threaded hole ...turn the chuck by hand to produce desired chamfer width...or get your money back... |
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