E30 Zone

evening folks,

looking for a bit of advise in regards to my daily (audi a4 b6 1.9tdi)

i'm in the middle of replacing the right rear abs sensor (the one that always seems to o on audi/vw of any age.) & the bolt that holds the sensor in place has snapped, the head has come off),

now that made it possible for me to remove the dud sensor but leaves me stuck on how to remove the remains of the bolt.

i'm trying to avoid removing the hub & bearing (as that would mean replacing those as well) to drill it out.
but i'm stuck when it comes to tools for the job, i don't have access to an induction heater/hot spanner or a blow torch.

but, i do have a 50W soldering iron, as i saw on the repair shop show (don't ask....) & one of them used the same thing to free off a rusted in bolt on a bit they were working on,

would a soldering iron heat up a 6mm bolt enough to break the bond the rust has made?
has anyone tried this method before??

Any pics Steve please ?

Mart.

martauto wrote: ↑

Tue Jun 06, 2023 5:33 pm

Any pics Steve please ?

Mart.

not at the moment, i need to get the car back in the air, i'll try to get some tomorrow if i can.

You would need a few KW to get any amount of heat into that, stick it in with some silicone and get back to work on the E30

DanThe wrote: ↑

Tue Jun 06, 2023 7:56 pm

You would need a few KW to get any amount of heat into that, stick it in with some silicone and get back to work on the E30

cheers dan sounds like an idea, i've got some tiger seal in the shed

steve_k wrote: ↑

Tue Jun 06, 2023 5:22 pm

but, i do have a 50W soldering iron, as i saw on the repair shop show (don't ask....) & one of them used the same thing to free off a rusted in bolt on a bit they were working on,
would a soldering iron heat up a 6mm bolt enough to break the bond the rust has made?
has anyone tried this method before??

As Dan says you will need more than a soldering iron, even on 6mm. I use a small plumbing MAPP blow torch and it works really well, useful for lots of things.

If it falls off with silicone use araldite

flybynite wrote: ↑

Wed Jun 07, 2023 8:19 am

steve_k wrote: ↑

Tue Jun 06, 2023 5:22 pm

but, i do have a 50W soldering iron, as i saw on the repair shop show (don't ask....) & one of them used the same thing to free off a rusted in bolt on a bit they were working on,
would a soldering iron heat up a 6mm bolt enough to break the bond the rust has made?
has anyone tried this method before??

As Dan says you will need more than a soldering iron, even on 6mm. I use a small plumbing MAPP blow torch and it works really well, useful for lots of things.

If it falls off with silicone use araldite

well to be on the safe side i've got a small mapp blow torch on the way from amazon,
might even have some jb weld somewhere.

Best way is to dot punch the centre and drill it out with a diamond tip or hard carbide drill bit, apply heat and use an easy out to shift it, or drill it out to size and re-tap the thread.

well it looks like i'll be (trying to) drill it out.

after using nearly a can & a half of gas & getting the bolt nice & cherry red it still wouldn't budge.
so time to find the right size hard carbide drill bit & go at it again.

tiger sealing the new sensor in is looking very tempting.

steve_k wrote: ↑

Fri Jun 09, 2023 9:16 am

well it looks like i'll be (trying to) drill it out.
after using nearly a can & a half of gas & getting the bolt nice & cherry red it still wouldn't budge.
so time to find the right size hard carbide drill bit & go at it again.
tiger sealing the new sensor in is looking very tempting.

Be careful how you use heat, for an outside bit (like a nut) try to get it off when hot. For a bolt you need to heat it and let it cool.

I give it a bit of heat then cool it with some WD40 and repeat. Heating a bolt cherry red is not that helpful, you just need to break the bond.

Drilling a small hole and banging in a torx bit sometimes works but for a 6mm, I tend to drill and tap out most of the time.

Good luck

flybynite wrote: ↑

Fri Jun 09, 2023 12:04 pm

steve_k wrote: ↑

Fri Jun 09, 2023 9:16 am

well it looks like i'll be (trying to) drill it out.
after using nearly a can & a half of gas & getting the bolt nice & cherry red it still wouldn't budge.
so time to find the right size hard carbide drill bit & go at it again.
tiger sealing the new sensor in is looking very tempting.

Be careful how you use heat, for an outside bit (like a nut) try to get it off when hot. For a bolt you need to heat it and let it cool.

I give it a bit of heat then cool it with some WD40 and repeat. Heating a bolt cherry red is not that helpful, you just need to break the bond.

Drilling a small hole and banging in a torx bit sometimes works but for a 6mm, I tend to drill and tap out most of the time.

Good luck

thanks for that.
thats my idea with the remains of the bolt, heat then cool, if i have to drill it out i'll retap it or failing that a nut & bolt will hold it in place.

Avoid using carbide bits with a hand held drill as they are very brittle.
A normal HSS bit will be fine just keep the revs down and use some WD 40.

Mart.

martauto wrote: ↑

Fri Jun 09, 2023 3:46 pm

Avoid using carbide bits with a hand held drill as they are very brittle.
A normal HSS bit will be fine just keep the revs down and use some WD 40.

Mart.

thanks for the advise mart i've got some of those in the shed so i'll see if i've got one small enough.

I can send you some if you like mate ??

Mart.

martauto wrote: ↑

Fri Jun 09, 2023 6:37 pm

I can send you some if you like mate ??

Mart.

really?? thank you that would be a massive help.

thank you.

I would personally MIG weld a nut on the end of the stub - the heat helps work them loose, then it should undo quite easily with a suitable spanner/socket/Mole grips.

Best to work them loose gradually, starting by tightening a bit, then working it in and out until it unscrews easily.

Speedtouch wrote: ↑

Sat Jan 25, 2025 10:07 pm

I would personally MIG weld a nut on the end of the stub - the heat helps work them loose, then it should undo quite easily with a suitable spanner/socket/Mole grips.
Best to work them loose gradually, starting by tightening a bit, then working it in and out until it unscrews easily.

Good advice for posterity, but Steve-k passed away last year. Been a bad couple of years for Zone members, all before their time.

Indeed, sorry to hear of their passing.