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Unlucky day! Trying to fit C4 roof bars

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Fri Jun 04 2010, 10:52am
Member No: #13367
Joined: Apr 18 2010
Location: Swindon
Having decided that today would be a good day to fit my roof bars for the first time, I went to my garage with all the enthusiasm in the world!

I started to tap out the drivers side thread with the tool provided and after a couple of millimetres decided to give it a rest and tap the others a little. I then went back to the drivers side and continued to tap out the front and rear for the next 30 mins or so until my mate came over to help save my thumbs from getting too blistered.

After he had been at it for about 20 mins we decided a break was in order and took a trip to Halfords to check out the roof bike racks for a laugh...

Having had our laugh we popped in to the Range next door and got a set of slightly longer Allen keys as this would provide more leverage with the increasingly difficult tapping. (I have never known tapping to be so laborious)
After about another 15 mins I managed to shear off the tapping tool in the hole above the drivers door, ****!!!

"Not a problem", said I, "we shall go to B&Q and get the relevant extractor tool, drill bit and new tapper to continue."

After a trip to B&Q to get the extractor tool (£9) a cheeseburger (£3) and Machine & Mart to get a tapping set (£17) ...as B&Q didn't have any in... we set back to work - my mate tapping out the other holes amazingly easily with the new tapper and myself drilling the old tapper to get the extractor tool in.

He finished tapping the other holes just as I finished drilling the hole. Now more confident of getting the roof rack fitted before the sun went down, I set to with the extractor tool by hand.... SHEARED THE ****ING BLIGHTER OFF IN THE HOLE TOO!!!! unsurprisingly birds leapt from the trees several blocks away as I proceeded to let the whole neighbourhood know how I felt about this... a cigarette was thrust into my hand and promptly lit!!!

I now have no idea what to do as the extractor bit is of a much hardened state than the previous tapping tool that I was trying to extract, and has dulled my 2 new drill bits! (more expletives here)

Any advise will be greatly appreciated.

I would like to mention that if anyone is going to fit a roof rack to a 4yr old car, then buy a proper 6m tapper or set before hand rather than use the Allen key tapper bolt provided, as it saves a lot of time, money and frustration!

I tried taking a pic, but it didn't come out at all well.
Fri Jun 04 2010, 11:06am

Member No: #6049
Joined: Nov 05 2008
Location: Bracknell
Definitely not good. I recently had to "extract" one of my old locking wheel nuts as the fool who put the wheel on machined it on and knackered the head. Prayed that the bolt extractor bit wouldn't snap as I knew exactly how hard they are to remove.

A normal drill bit doesn't stand a chance against the extractor bit. Your best bet would be to try with some form of high-strength bit but it's going to be a long process.

I'm sure other people may have other ideas to try too.
Fri Jun 04 2010, 11:20am
Member No: #13323
Joined: Apr 15 2010
Location: Devon
Had the same problem last week when I fitted my roof bars. The holes were really tight so i sprayed the holes with WD40 and tried again. Took 20 or so minutes to 'tap' them with a normal bolt but was able to just about tighten them all up. One thing to remember though is the wind noise, it gets pretty bad at about 50mph
Fri Jun 04 2010, 11:28am
Member No: #13367
Joined: Apr 18 2010
Location: Swindon
Thanks Diggerdollly,
I have to get them on first! I will only have them on the car when transporting bikes, being a coupe I don't want them on permanently. However, when I do get a resolution to this (and I will!!) they threads will be well greased and I shall also put in some shorter bolts finger tight for when not in use.
Fri Jun 04 2010, 12:41pm

Member No: #69
Joined: Jan 10 2007
Location: Derby, England
Have you tried removing the Hardened easy out(if thats what you've used to get the tap out) with a dremel or similar type with a bur fitted?

Also try if you can by drilling very slow speed that should work too.
Fri Jun 04 2010, 01:25pm

Member No: #1
Joined: Aug 07 2006
Location: Northumberland
The 'extractor' tools are, by the nature of the job they have to do, a lot 'harder' than the drill bits your trying to use on them to drill them out.

All you can do if you can't find some seriously hard, tungsten bits to try and re drill them (as you can't apply serious heat, then let then cool to soften them), is try and break it out with a punch and lump hammer, or as Ham says, a dremel with a fine bur tool to cut through it.

It might even be easier to try and chop the problem mounting point out completely and weld a new one in.
Fri Jun 04 2010, 03:27pm
try COBALT drill bits,available from machine mart about 20 quid for a set.they are rock hard and can make mincemeat out of any steel surface including stainless steel.use them at work all the time.not only rock hard but last forever!

good luck.
Fri Jun 04 2010, 06:05pm
Member No: #13367
Joined: Apr 18 2010
Location: Swindon
C6 Dave wrote ...

It might even be easier to try and chop the problem mounting point out completely and weld a new one in.

My brother tried a dremmel when he sheared off a bolt in the hole to no avail.
I have drilled a hole down one side of the offending "easy out" (ha ha) bit with the hope of then punching it out from the side and then drilling the rest out... no luck there either.
I will think quite seriously about welding in a new panel with bolt if required, but only when I have tried everything else.

Cobalt bit... hmm, I thought of diamond tipped but that sounds like a viable option... guess where I will be going (again) tomorrow!!

Thanks Guys
Fri Jun 04 2010, 06:32pm
Member No: #1556
Joined: Nov 12 2007
Location: Stoke-on-Trent
The cobalt drill bit should be the answer.

Any reputable machine tool supplier would be able to help, and while your in there get some proper taps. Sounds like the ones Citroen supply have been found in a cheap Christmas cracker.

Cromwell Tools are a nationwide supplier and should have a branch near you.

Also, don't force the tap. When it grinds to a halt STOP !!!!! There is too much crud at the front of the tap to do the work it was designed for. It is supposed to clean out the tread not cut a new one. When you feel resistance back it up, squirt with tap fluid and clean the tap before starting again.

Buy some proper drill/tap fluid as wd40 won't be good enough, its just a posh lube.

When i did mine they were in a bad way, but didn't struggle to do the job. I also plug the hole with stubby allen screws, again a quick squirt of wd40 before cappig off.

Good luck, and take you time.

Fri Jun 04 2010, 08:01pm
Member No: #5650
Joined: Oct 03 2008
Location: Portsmouth, UK
Bin-The-L-Plates wrote ...

Buy some proper drill/tap fluid as wd40 won't be good enough, its just a posh lube.

I highly recommend Rocol RTD Compound, Liquid or Spray.
Sat Jun 05 2010, 04:29am
Member No: #1443
Joined: Oct 28 2007
Location: Wiltshire
If you need some cobalt drills i have some here by Lyneham just down road from you that you can have.
Sat Jun 05 2010, 05:09am
Member No: #13367
Joined: Apr 18 2010
Location: Swindon
Hi Honeymonster,
Thanks, do you know how to make them work??
I went out and bought some this morning and have been optimistically not making a single mark in the stuck "easy out" broken bit!
I did manage to break my 1.5mm and 2mm in the process... I have been heeding all advice, plenty of lube and slowly with the drill and no pressure... but it just wont give!
Sat Jun 05 2010, 06:23am
Member No: #1443
Joined: Oct 28 2007
Location: Wiltshire
Hi there yes you need slow speed and patience we use them for drilling titanium on the aircraft and removing snapped easy outs .

I am in all day today if you fancy a run out to lyneham I can have a look for you if you need it .
Sat Jun 05 2010, 11:33am
Member No: #11625
Joined: Nov 30 2009
Location: aberdeen
Honeymaster, I'd be trying to drill some holes around the broken easyout (ie not into it) and then smashing or chipping away at it with a punch.

You might then need to find a Tig welder who can deposit some soft metal into the resulting crater. Then drill out and tap

This really needs a sticky and a warning to use a proper plug M6 tap and tap wrench instead of the toy they provide.

If it's any consolation, I had pretty much the same problem as you.


Sat Jun 05 2010, 11:48am
Member No: #13367
Joined: Apr 18 2010
Location: Swindon
gmerry wrote ...

This really needs a sticky and a warning to use a proper plug M6 plug and tap wrench instead of the toy they provide.

If it's any consolation, I had pretty much the same problem as you.

I would definitely recommend to everyone planning on fitting roof rack/bars to spend the £17 on a proper tapping set, and NOT using the ... excuse they provide!

I popped over to HoneyMonsters this afternoon. He had a good go at it, and we decided that maybe going to a body shop and let them sort it (come back if they make a mess!)

I did speak to the owner earlier today of a local one who reckons that one of his mechs should be able to electro-weld on a nut and extract it that way. Failing that I think I shall be going down the cut-it-out-and-replace-the-panel route.

I did notice a couple of stud divots on the small panel and some sealant under it, so it may be bolted in place (fingers crossed) however, after removing the roof lining on that corner I could see that even if there were nuts there to hold it in place... you cant get to the blighters!

The saga continues... I shall be popping to the body shop on Monday am for a mechanic to have a go at, I shall let you all know how it goes!
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