Lotus Elan

Rear brake bleed nipple

PostPost by: englishmaninwales » Sun Jun 16, 2019 5:51 am

I’m going to replace a rear brake caliper bleed nipple (3/8 UNF 24 tpi according to this forum) as it continues to weep very slightly after bleeding the brakes.
Looking on eBay, wanting to avoid poor quality (cheap multi packs), some are more expensive and described as steel - is this a sensible choice or snake oil?

Second question, is it an accepted practice to use anti seize eg copper slip, or is that a risk for brake fluid contamination?

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PostPost by: UAB807F » Sun Jun 16, 2019 6:17 am

I thought they were all steel, or does the advert mean "stainless steel" ?

Personally I don't use any compounds on brake threads. I have used ptfe tape (like plumber's use) because I find that stops any by-pass down the threads when bleeding, but it's not a big deal. I can't see any reason not to use copper slip though, it's on the back end of the system and providing it's only on the threads I'd expect it's unlikely to migrate into the caliper against fluid pressure.

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PostPost by: prezoom » Sun Jun 16, 2019 3:41 pm

Buy a pair of Speed Bleeders. They have a sealing compound on the threads and turn brake bleeding into a one person job. They come in both 3/8-24 long and short.
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PostPost by: patrics » Tue Jun 18, 2019 8:04 pm

Bleed screws originally would probably have been made in 1A steel - cheap. Stainless would definitely not be suitable as too hard. The bleed screw should deform before the bleed port seat.
These days there are obviously different types, but generally "copper slip" would be mineral based and definitely not suitable.

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