Hello

I'm working on son-in-laws Fiesta Mk6 face-lift (56 plate) version, changing front pads and discs. O/S completed no problem but N/S I've got the caliper off but cant get the upper bolt from the carrier and it's rounding. I've been using an electrical type impact driver but failed miserably with this bolt.

There's not much room to hammer on a bolt remover. I did think of a nut breaker and whack it with a hammer. But standby plan is angle grinder to remove the head and then I'm guessing the remains of the bolt shaft will withdraw when the disc and carrier is slid off.

Can anyone confirm that, or offer a better idea? I'm hesitant with heat and tried penetrative fluid without success.

Getting desperate, all ideas appreciated! 

Edited January 20, 20251 yr by Meekoblue
Grammatically incorrect!

I'd go with heat, doing what you can to focus on heating/cooling just the bolt to expand/contract it. Remove the slide pins and boots so they don't get damaged.

Make the most of the fact you have access to the tail end of the bolt too (this is likely also the reason why its seized). Penetrating fluid tends not to work too well when heating a fixing as it evaporates before doing any good however applying wax or crayon after heating can really help as it has a good chance of being drawn in to the threads.

I would be hesitant to be chopping anything off at this stage. You might make the problem worse! You can always keep that as a Plan B.

Thanks for the advice. Not tried heat and not much experience of doing so.

From what i can make out there isn't any thread protruding out the back of the carrier so it's just the head of the bolt to work with.

Anyone have experience of the impact driver bolt removers (like a socket with an anticlockwise helical cutting edge inside to dig in while trying to twist it out)?

There won't be protruding threads but you should be able to see the end of the bolt.

Re the bolt remover, whilst I haven't use that exact type I have had success in the past just hammering on an undersized socket to a rounded bolt head! It's not great for the socket but desperate times sometimes call for desperate measures!

I agree: this bolt will be dealt with extreme prejudice!  I need to get the bugger out so will bear that in mind about an undersize socket too. Thanks.

You must use 6-sided sockets, hope you are. The bolt has possibly got thread lock on it Heat from a hot air gun will soften the threadlock. With mine, I use a T-bar and 6-sided socket and wack the T-bar with a small lump hammer in the unscrew direction a few times. Renew the bolt if it's starting to round (once you've removed it) 

Thanks for the reply. Definitely 6-sided decent sockets. Ive ordered a blow lamp and freezer spray. Need to shield the bits that won't like heat but fingers crossed. And new bolts on order too!

An electric heat gun is safer than a flame torch use it on hottest setting for a good 5-10 minutes will really help. Oh, and keep the heat well away from the cv boot! (don't ask.....) 

Ok thanks ill try that. Ive a paint stripper type electric heater gun.

...and I can imagine!

I think you'd be there forever and a day with a heat gun as they are relatively low temperature (hundreds rather than thousands of degrees) and lacking focus so all the surrounding metal would be sapping away whatever heat it could muster.

Make sure you're using an impact socket first 6 side hex NOT star

Spray some penetrating oil in both ends, leave for 10-20 mins then smack the head with a heavy hammer to shock the bolt

If the head does fail DON'T cut anything, weld a nut to the head and then undo with lots of heat