"Pixel" (Improbcat)
09/08/2018 at 10:25 • Filed to: Project Colony Ship, Project Car
4
8|
"Pixel" (Improbcat)
09/08/2018 at 10:25 • Filed to: Project Colony Ship, Project Car | 4
| 8 |
Spent the morning replacing the rusted chunks that had once been the wagon’s front brake calipers. Since I was replacing them I upgraded to the heavier duty Police calipers and severe duty pads.
Did a bunch of bleeding and still couldn’t get a decent pedal. Took it for a test drive and the brakes are terrifying. There was some crud in the bottom of the Master Cylinder, and I suspect the bleeding pulled something into the bore and damaged a seal.
Fortunately a reman MC is only $19. Unfortunately I’m not sure if I’ll have time for the job this weekend, as I give the brake lines a 50/50 shot of surviving being removed.
ITA97, now with more Jag @ opposite-lock.com
> Pixel
09/08/2018 at 11:05 |
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When replacing major brake parts like master cylinders and calipers, it can sometimes take gravity bleeding the system first before pressure (or vacuum) bleeding to get all the air out.
Urambo Tauro
> Pixel
09/08/2018 at 12:01 |
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What’s different on the police calipers?
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Pixel
> Urambo Tauro
09/08/2018 at 15:09 |
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Steel vs phenolic piston. Slightly larger bore (uses sam MC).
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Urambo Tauro
> Pixel
09/08/2018 at 15:20 |
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Phenolic... resin? Didn’t know that was used as piston material. I guess i t’s not surprising, seeing as it’s been used for timing sprockets too.
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Pixel
> Urambo Tauro
09/08/2018 at 16:36 |
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Yeah. Apparently it reduces heat transfer to the brake fluid. But if it does get overheated it tends to warp and stick in the bore. Thus police getting steel version.
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Urambo Tauro
> Pixel
09/08/2018 at 17:46 |
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Huh. So the resin is better at reducing heat transfer , but more vulnerable to overheating... t herefore steel holds up better against overheating, but allows for more heat transfer. .. S ounds counter-productive.
Of course I expect the police brakes to be more severe-duty, so apparently this means that it must be okay to allow for some extra heat transfer in order to avoid warped pistons. But if that’s the case, then why worry about heat transfer at all in civilian car s?
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Pixel
> Urambo Tauro
09/08/2018 at 18:43 |
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This on a Full sized wagon. So maybe the concern for civilians was riding the brakes or overloading it with people/stuff/trailer and boiling the brake fluid duty to extended lighter braking. But if they managed to overheat it and warped it and their brakes stuck they could get it towed and fixed. But with cop crown vic sedans the concern was limited but very hard braking , and keeping everything working to avoid tows/downtime.
Or the phenolic was slightly cheaper, given this is 80s Ford that might be all.
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Urambo Tauro
> Pixel
09/08/2018 at 20:49 |
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Hm. Wouldn’t be surprised if it really was just a cost-cutting measure. At any rate, if it came down to it, I think I’d rather have to deal with boiled fluid than stuck pistons. Nice upgrade!