*%#@! Bleed Screw

K9Leader · 01-19-2023, 11:46 AM

Refurbishing a set of 335 brake calipers for my 128 and bleed screw seized and snapped off:

I will start my search on the Google machine to see how best to get this out but any wisdom the forum can share will be appreciated.

ZeroR · 01-19-2023, 12:55 PM

Ah yes, bleed screws are fragile little suckers. I have my fair share of broken bleed screws. I have come learn not to put too much torque on them when tightening AND loosening. If I feel a lot of resistance, I stop.

My suggestions is penatrating oil to try to get the rest of the screw to move. And use screw extractor twist it out. I have seen some people use heat to get the screw out but I try not to for calipers. Since you are refurbishing the calipers and they are off the car and all the fluid is out then it might be okay. Good luck!

K9Leader · 01-19-2023, 01:03 PM

Quote:

Originally Posted by ZeroR

Ah yes, bleed screws are fragile little suckers. I have my fair share of broken bleed screws. I have come learn not to put too much torque on them when tightening AND loosening. If I feel a lot of resistance, I stop.

My suggestions is penatrating oil to try to get the rest of the screw to move. And use screw extractor twist it out. I have seen some people use heat to get the screw out but I try not to for calipers. Since you are refurbishing the calipers and they are off the car and all the fluid is out then it might be okay. Good luck!

Yep, they are soaking in penetrating fluid and I guess it is time to get some sort of screw extractor set more heavy duty that some ez out bits.

Thanks for the response!

tracer bullet · 01-19-2023, 02:30 PM

Agreed 100% with ZeroR above. Penetrating oil will help, it's miraculous stuff. Screw extractors sometimes actually work, it's amazing because usually good ideas fall flat, but I've had them work on various car parts in the past.

Heat as a last resort but yep if you are rebuilding it should be OK. Do try getting them 100% torn apart first, not just afterwards, so there's no rubber or brake fluid and such at the time.

Heating is cool, red-hot parts expand into each other, so the screw pushes into the caliper while the caliper tries to contract the hole (pushed on from the outside) at the same time. Since the screw and caliper can't be in the same space at the same time, the stronger caliper slightly forces the screw to deform and get a little more narrow, but longer. I suppose the screw deforms the caliper as well but barely. When it all contracts later after cooling you get the parts to have a bit of a gap. Maybe folks know this but FYI if not.

K9Leader · 01-20-2023, 11:23 AM

I've spent all morning working on it - used penetrating oil, used heat, used bolt extractor bits with an impact. Pretty much succeeded in rounding it down to smaller than my smallest bolt extractor. Several DIY videos I watched advocated inserting the smooth end of a drill bit into the hole so that it is solid in the middle and won't collapse/soften, which made some sense but makes drilling it out more difficult. Also, in drilling out, I would be concerned about damaging the threads/hole in the caliper.

I will go ahead and try cutting a slot and flat heading it but I do not see how that will achieve anything if the bolt extractors on an impact could not.

I've scoped out several listed on Ebay and told the sellers I would buy theirs if they can remove the bleed screw before shipping - I don't want to end up having to do this again.

tracer bullet · 01-20-2023, 12:11 PM

Dang!

Well - at some point, you can get more crazy, you have nothing to lose...

What sort of extractor did you use? If you haven't already, you can try the kind where you drill a hole through the bleeder, then stick the extractor (basically a reverse thread type thing) down in there and hope you can "unscrew" the bleeder. Maybe you didn't but I wasn't sure. If not, it means of course more time, another tool, and so on. And the harder it works the more it pushes the screw towards the caliper, from the inside, creating more friction there.

Heat - torch, red hot, usually does it. But it's gotta be red hot. If you haven't done that much heat, you could try it, if you can think of anything in the area that has oxy/acetylene set up.

I don't know, but I wonder, if you can drill and tap to the next size hole? I would think there are oversized options available.

At some point, yeah, another caliper is the answer. But once you get there it means you have freedom to do anything and everything to this one first.

scratchgolf135 · 01-20-2023, 03:51 PM

Will needle nose vice grips fit in there? I had to make an aggressive slot in one of the screws that holds our coolant line to the top of the subframe. That was the only way I could get it out using a flat bit in my 1/4 impact.

Blau · 01-20-2023, 09:37 PM

Vise clamp it upside down and drill that bitch out. Shop vac it good and clean, run fluid through it a few times, retap the hole and send it.

K9Leader · 01-21-2023, 10:20 PM

I went ahead and ordered another caliper after confirming with the seller that the bleed screw was removable. The other three calipers I have (another 335 caliper for the front and two 328 rears) were no problem removing the bleed screw.

It had reached the point of diminishing returns - further solutions would require buying more tools or repair parts so no longer worth it. New one will be here in a day or two so I will get back to it next week.

Blau · 01-22-2023, 10:29 AM

Quote:

Originally Posted by K9Leader

I went ahead and ordered another caliper after confirming with the seller that the bleed screw was removable. The other three calipers I have (another 335 caliper for the front and two 328 rears) were no problem removing the bleed screw.

It had reached the point of diminishing returns - further solutions would require buying more tools or repair parts so no longer worth it. New one will be here in a day or two so I will get back to it next week.

I'll take the broken one off your hands for the price of shipping. PM me if you're interested.

deepsix · 08-11-2023, 03:08 PM

I ran into a similar issue when bleeding my brakes for the first time. I cross threaded the front passenger bleed screw when torquing to spec and it no longer kept a seal.

I ended up ordering a re-manufactured caliper for both front brakes as I did not see it worth while trying to tap a larger thread and potentially allowing metal shavings into the brake system.

After installing the new caliper I realized the fitting on the hard brake line where the rubber brake hose attaches was also seized and would not spin. As a result the brake hose was twisted a bit as you need both the fitting on the brake hose and the fitting on the hard line to spin independently.

After some research I found that most aftermarket braided brake hoses have a fitting that allows rotation unlike the stock hose. So to avoid trying to un-seize the brake hard line fitting and potentially breaking that, I opted for new braided hoses.

I ordered some HEL Performance braided hoses and everything went back together perfectly.

I found this video helpful in solving my issue:

01-19-2023, 11:46 AM	#1
K9Leader Captain 1051 Rep 782 Posts Drives: 2010 328ix E91, 2011 128i E82 Join Date: Feb 2018 Location: Delaware iTrader: (0) Garage List 2011 BMW 128i [10.00] 2010 BMW 328i [10.00]	%#@! Bleed Screw Refurbishing a set of 335 brake calipers for my 128 and bleed screw seized and snapped off: I will start my search on the Google machine to see how best to get this out but any wisdom the forum can share will be appreciated. __________________ K9Leader* 2010 328i x-Drive, E91 - Space Gray/Black 2011 128i E82 6MT - Crimson Red/Black
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01-19-2023, 12:55 PM	#2
ZeroR Track Addict 16 Rep 26 Posts Drives: 128i Join Date: Mar 2018 Location: Canada iTrader: (0)	Ah yes, bleed screws are fragile little suckers. I have my fair share of broken bleed screws. I have come learn not to put too much torque on them when tightening AND loosening. If I feel a lot of resistance, I stop. My suggestions is penatrating oil to try to get the rest of the screw to move. And use screw extractor twist it out. I have seen some people use heat to get the screw out but I try not to for calipers. Since you are refurbishing the calipers and they are off the car and all the fluid is out then it might be okay. Good luck!
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01-19-2023, 02:30 PM	#4
tracer bullet Brigadier General 2413 Rep 3,549 Posts Drives: '11 135i , '15 X3 35i Join Date: May 2011 Location: Saint Paul, MN iTrader: (1)	Agreed 100% with ZeroR above. Penetrating oil will help, it's miraculous stuff. Screw extractors sometimes actually work, it's amazing because usually good ideas fall flat, but I've had them work on various car parts in the past. Heat as a last resort but yep if you are rebuilding it should be OK. Do try getting them 100% torn apart first, not just afterwards, so there's no rubber or brake fluid and such at the time. Heating is cool, red-hot parts expand into each other, so the screw pushes into the caliper while the caliper tries to contract the hole (pushed on from the outside) at the same time. Since the screw and caliper can't be in the same space at the same time, the stronger caliper slightly forces the screw to deform and get a little more narrow, but longer. I suppose the screw deforms the caliper as well but barely. When it all contracts later after cooling you get the parts to have a bit of a gap. Maybe folks know this but FYI if not.
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01-20-2023, 11:23 AM	#5
K9Leader Captain 1051 Rep 782 Posts Drives: 2010 328ix E91, 2011 128i E82 Join Date: Feb 2018 Location: Delaware iTrader: (0) Garage List 2011 BMW 128i [10.00] 2010 BMW 328i [10.00]	I've spent all morning working on it - used penetrating oil, used heat, used bolt extractor bits with an impact. Pretty much succeeded in rounding it down to smaller than my smallest bolt extractor. Several DIY videos I watched advocated inserting the smooth end of a drill bit into the hole so that it is solid in the middle and won't collapse/soften, which made some sense but makes drilling it out more difficult. Also, in drilling out, I would be concerned about damaging the threads/hole in the caliper. I will go ahead and try cutting a slot and flat heading it but I do not see how that will achieve anything if the bolt extractors on an impact could not. I've scoped out several listed on Ebay and told the sellers I would buy theirs if they can remove the bleed screw before shipping - I don't want to end up having to do this again. __________________ K9Leader 2010 328i x-Drive, E91 - Space Gray/Black 2011 128i E82 6MT - Crimson Red/Black
	Appreciate 0 Quote

01-20-2023, 12:11 PM	#6
tracer bullet Brigadier General 2413 Rep 3,549 Posts Drives: '11 135i , '15 X3 35i Join Date: May 2011 Location: Saint Paul, MN iTrader: (1)	Dang! Well - at some point, you can get more crazy, you have nothing to lose... What sort of extractor did you use? If you haven't already, you can try the kind where you drill a hole through the bleeder, then stick the extractor (basically a reverse thread type thing) down in there and hope you can "unscrew" the bleeder. Maybe you didn't but I wasn't sure. If not, it means of course more time, another tool, and so on. And the harder it works the more it pushes the screw towards the caliper, from the inside, creating more friction there. Heat - torch, red hot, usually does it. But it's gotta be red hot. If you haven't done that much heat, you could try it, if you can think of anything in the area that has oxy/acetylene set up. I don't know, but I wonder, if you can drill and tap to the next size hole? I would think there are oversized options available. At some point, yeah, another caliper is the answer. But once you get there it means you have freedom to do anything and everything to this one first.
	Appreciate 0 Quote

01-20-2023, 03:51 PM	#7
scratchgolf135 First Lieutenant 281 Rep 372 Posts Drives: alpine white 135i Join Date: Apr 2012 Location: Fishers, IN iTrader: (0)	Will needle nose vice grips fit in there? I had to make an aggressive slot in one of the screws that holds our coolant line to the top of the subframe. That was the only way I could get it out using a flat bit in my 1/4 impact.
	Appreciate 0 Quote

01-20-2023, 09:37 PM	#8
Blau J 367 Rep 697 Posts Drives: BMW 128i Join Date: Feb 2019 Location: Connecticut iTrader: (0) Garage List 2011 BMW 128i [6.00] 2013 BMW X3 28i [0.00]	Vise clamp it upside down and drill that bitch out. Shop vac it good and clean, run fluid through it a few times, retap the hole and send it.
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01-21-2023, 10:20 PM	#9
K9Leader Captain 1051 Rep 782 Posts Drives: 2010 328ix E91, 2011 128i E82 Join Date: Feb 2018 Location: Delaware iTrader: (0) Garage List 2011 BMW 128i [10.00] 2010 BMW 328i [10.00]	I went ahead and ordered another caliper after confirming with the seller that the bleed screw was removable. The other three calipers I have (another 335 caliper for the front and two 328 rears) were no problem removing the bleed screw. It had reached the point of diminishing returns - further solutions would require buying more tools or repair parts so no longer worth it. New one will be here in a day or two so I will get back to it next week. __________________ K9Leader 2010 328i x-Drive, E91 - Space Gray/Black 2011 128i E82 6MT - Crimson Red/Black
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08-11-2023, 03:08 PM	#11
deepsix Registered 3 Rep 4 Posts Drives: 2018 F31 330i, 2011 E82 128i Join Date: Jun 2023 Location: Canada iTrader: (0)	I ran into a similar issue when bleeding my brakes for the first time. I cross threaded the front passenger bleed screw when torquing to spec and it no longer kept a seal. I ended up ordering a re-manufactured caliper for both front brakes as I did not see it worth while trying to tap a larger thread and potentially allowing metal shavings into the brake system. After installing the new caliper I realized the fitting on the hard brake line where the rubber brake hose attaches was also seized and would not spin. As a result the brake hose was twisted a bit as you need both the fitting on the brake hose and the fitting on the hard line to spin independently. After some research I found that most aftermarket braided brake hoses have a fitting that allows rotation unlike the stock hose. So to avoid trying to un-seize the brake hard line fitting and potentially breaking that, I opted for new braided hoses. I ordered some HEL Performance braided hoses and everything went back together perfectly. I found this video helpful in solving my issue:
	Appreciate 1 tracer bullet2413.00 Quote