Brake bleeders keep leaking

Another option: If OP still has the original calipers, those can usually be diy’er rebuilt using a caliper rebuild kit and some inexpensive specialty tools & brake hones. OP already knows the original calipers didn’t leak.

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Well good news on one front. The auto parts store has agreed to a refund instead of replace until I get a good one. Now, its just a matter of which way to go from here. I had planed on buying new oem…not so sure now. I would rebuild the old ones but I turned them in as cores so thats not gonna happen. I feel like my only two options are buy recycled oem calipers and rebuild them as neccesary or buy new oem. Thanks to everyone for their input.

Speaking of spark plugs…I almost got scammed by buying plugs on ebay. They were almost perfect counterfeit ngk. I returned them and bought replacements at my local auto store…

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Good Lord it sounds like a nightmare. It seems to have gotten worse, at least to me. I have returned countless “new” or reconditioned items and I’m just an average diyer.

Glad you made out like a bandit, sounds like you deserved every penny.

Quick question if you don’t mind. Let’s say I choose to rebuild some recycled calipers. Would there be a need to hone the cylinder if the piston rides on the square cut seal, as I believe it does? Assuming the cylinder bore isn’t rusty of course…

As DIY-er, I rebuilt few sets and did not need to hone it ever, but I was already scolded by Mr. @Tester on the similar “caliper rebuild” topic here: Use silicone grease (Sil Glyde) to protect caliper boots and guide pin boots----a good idea?

Once, I encountered a caliper with a small rust spot, which I polished out with 2000 grit sandpaper, and I did not see any ill effects of that.

On recycled parts, I would check if it is possible to push the piston in with pressure not exceeding “reasonable”, just to make sure it is not seized.

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Personally I have never seen this happen before. You should remove the bleeder bolt and look at the tip of the bolt as well as where the tapered end of the bleeder seats in the caliper. There is something wrong with the caliper most likely…or there is a piece of debris at the bottom of the bleeder hole in the caliper.

Using new bleeders with a fouled caliper bleeder hole will produce the same results. Perhaps there is a piece of steel at the bottom of the hole? Or something of that nature.

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There may be debris in the bleeder holes, but why should the OP be responsible for cleaning them out? Shouldn’t that have been done before assembly at the factory?

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@jtsanders … Why should they be responsible? They shouldn’t but I mean if they are leaking all over his driveway and there is simply a piece of something that can be extracted in order to stop the leak then you simply do what needs doing. Probably isn’t going to be that simple tho…

I wonder if the wrong bleeder screws are being used. Metric vs SAE.

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When I had multiple bleeder leaks on new calipers, there was no debris and the screws fit fine. It was definitely a machining defect.

I’ve only rebuilt wheel cylinders (and master cylinders) for drum brakes, never had occasion to rebuild a brake caliper. But it seems like it’s the same idea, just a simple piston & seal inside a metal cylinder. I’d guess to do the job correctly you’d have to hone the cylinder no matter the cross section of the seal. In any event on the wheel cylinders (& masters) I’ve rebuilt there has always been some corrosion or gunk build-up on the surface of the cylinder wall. That’s why they needed to be rebuilt, as those surface imperfections eventually damage the piston’s seals. It’s not exactly rocket science to hone a cylinder, it rarely takes more than 5 minutes (if it does I just buy another wheel cylinder), and the honing-tool is (or at least used to be) inexpensive. Here’s one for $8.

That’s why it is important to replace brake fluid every 2-3 years max, like a clockwork, then you do not need to worry about rust inside.

Fluid sucks water from the air like a sponge → rust is getting formed inside

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I believe the term you are looking for @thegreendrag0n is “Hygroscopic”… and you are correct. Brake fluid is very Hygroscopic in nature .

Why the term isn’t Hydro-scopic I will never know…but i never forgot it because of that spelling trait. Anyone else need some more useless info… I have an abundance…

Why do flammable and inflammable mean the same thing? You got to know this has caused some problems! … lol …

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I know the term, but I specifically wanted to stay our of it, just to keep it simple, now you brought it up :slight_smile:

There is no need for a hone, the caliper bore does not have a refined finish, emery cloth will do.
The seal grove in the caliper must be clean and free from corrosion or pits.
The piston must be smooth and free of pits.

I always used crocus cloth.

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Crocus cloth! Learned something new today!

My guess on the rebuilt calipers,

The kid earning minimum wage that is supposed to media blast them clean gets carried away with blasting the bleeder port and ruins the machined seat.

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