Idiot attempts elementary car maintenance. Contains VAG shite & ham-fistedness.

[worldofceri]

Mrs_WorldofCeri's Golf received an advisory for thin front brake pads at the last mot.  No problem, thinks I;  I've done discs and pads before and some of those times, I didn't fuck it up.  WCPGW?

 

So, this morning I acquired appropriate friction materials from my favourite local factors, MVC.  (No relation to the defunct record store chain.)  Was pleased to find I was given Apec parts, as recommended by at least one member on here iirc.

 

Things started off well, as I managed to remove the first teeny-tiny disc retaining screw, despite it clearly having been mangled a bit by someone previously.  Just two bolts secure the caliper to the axle, thoughtfully protected from the elements by a handy rubber cap.  Unfortunately these have a hex head of a size never used by any other manufacturer in the history of engineering.  I have at least a dozen Allen keys and hex bits, but the collection stops at 6mm and resumes again at 8mm.  FFS!  A brief interlude ensues as I take a trip to Halfords for a 7mm hex bit.  

 

 

New tools acquired, light work is made of taking things apart and I get the piston pushed back in without drama.  Shiny new things are installed and reassembly is the reverse of removal, right.  Well, yeah, provided you don't strip the thread when putting the caliper bolts back in.

 

Noooooooooooooooooooooooooooooooo!

 

 

That's right.  I've stripped the thread.  Properly.  It looks like a blind hole ffs, no trace of a thread.  Does anybody know if this is fixable, or do I need a whole new stub-axle?

 

Can it be sorted with a helicoil, and if so, what do I need to install one.  I've never done it before so don't really know what's involved.  Do I need to buy an expensive kit or can I just drill the hole to a suitable size and bosh a helicoil in?  I understand they screw in and are held fast with the aid of Loctite - is that right?

 

Check this out:  This is the caliper bolt.  The thread pitch is 1.25, but is it an M9?  I have M8x1.25 and M10x1.25 taps and dies but they seem too small/large respectively.

 

 

I could do to sort this in the next couple of days as poss, and as the cars's pretty much immobile I don't know what I'll do if I can't sort it myself.  Any advice gratefully received!

 

Help me keep this stylish*, rare* and desirable* vehicle on the road.  (And Mrs_WoC from kicking me in the bo11ox.)

 

Cheers!

 

[scaryoldcortina]

you fucked it, go get a hub.

 

on the bright side, golf mk4 isn't hard to find in the scrapyards.

[worldofceri]

you fucked it.

 

Bollocks.

 

Cheers, SOC.

[twosmoke300]

You can get a m9 helicoil kit if you trust yourself to do the repair

[twosmoke300]

Blind hole - then show a pic of hole with light shining through it ? I'm confused

[worldofceri]

Sorry, blind hole is the wrong term.  I meant unthreaded hole.

[worldofceri]

You can get a m9 helicoil kit if you trust yourself to do the repair

 

I trust myself to change brake discs, but we know how well that went.

[scaryoldcortina]

You can get a m9 helicoil kit if you trust yourself to do the repair

hence the "go get a not fucked one instead" advice. There aren't many people I'd trust to helicoil a brake attachment.

[beko1987]

Alot of the hub wheel bolt holes did this on my old zx... I just out brand new wheel nuts in and tightened them up... Fucked them after 3 or 4 removals but lasted for 3 years without the wheel falling off again...

 

Ram an m10 in there and sell it before needing to do the discs and pads again?

 

I can't imagine a new whatever you need will cost more than buttons on ebay for one of those!

[steveo3002]

is it a caliper carrier that can be taken off ?   if so get a used one or take it to some one that can deal with helicoils  , its probably best you dont try your first helicoil install on your brakes lol 

 

engineers will do it for a bout £25 if the carrier comes off

[Bren]

Was it you that fitted a caliper to my vectra?

[scaryoldcortina]

is it a caliper carrier that can be taken off ?   if so get a used one or take it to some one that can deal with helicoils  , its probably best you dont try your first helicoil install on your brakes lol 

 

engineers will do it for a bout £25 if the carrier comes off

It's a golf mk4, the carrier is part of the hub assembly but at least it's removable from the strut.

[DodgeRover]

Not being familiar with exactly how this goes together but would it not be possible to use a longer bolt of appropriate rating and a nyloc nut on the back?

[scaryoldcortina]

No space for that, the disk sits right behind the hole and besides the "bolt" is also the caliper slider so finding one with a longer threaded section might be hard.

[pilninggas]

The first helicoil I ever did was brake related. Wasn't a problem, as long as you take your time it's a bloody good fix.

[sierraman]

It's too damaged to clean up with the tap. As above replacement hub from breakers.

[castros_bro]

File the hole clear of threads then put a bit of 9mm High tensile studding in the hole and arc weld it, use a ubiquitous M9 nylock to assemble the shitty mess 

 

 

Go and get a good hub/caliper carrier from a scrappy as these are important bits as bodging is not an option.

[scaryoldcortina]

I have no intentions of doing this to my brakes (for one they contain 0 stripped threads) so answer free from fear of legal repercussions....

 

If you drill/tap the hole correctly and the helicoil goes in correctly, what can go wrong? If its not done correctly I guess it can pull free attached to the bolt (which wouldn't be good on something you rely on to slow you down) .... but on the face of it it looks pretty straight forward?

 

I sit at a computer all day, whereas you work at this kind of stuff.... so please explain to a layman how it can go horribly wrong.

You have identified the thing that can and does go wrong. Badly done helicoils come out under load, and I've seen plenty of botched ones over the years. I don't recommend that anyone starts out doing a safety critical one, and the same advice goes for stuff like making your own brakepipes. Easy to do when you know how, possible massive accident if you mess up.

 

It's also worth considering that VW's finest* monkey metal hubs aren't the easiest things to tap and drill with any degree of success, the ease with which it shed its original thread might be a clue here. They even manage to write themselves off by ovalling the track rod end taper or smashing in half while you are trying to change a wheelbearing.

 

PS, if you are buying a hub from a scrapper you need to make sure it has the same pads and disk as your car - there are at least three variants (because the caliper carrier is part of the hub).

[RoadworkUK]

I once toyed with the idea of fitting Audi TT caliper carriers to my A4 to enable the fitment of bigger discs, but they were £HOW MUCH? so I abandoned that plan.

 

Actually quite surprised the Golf has a different setup to the TT.

[worldofceri]

 Badly done helicoils come out under load, and I've seen plenty of botched ones over the years. I don't recommend that anyone starts out doing a safety critical one, and the same advice goes for stuff like making your own brakepipes. Easy to do when you know how, possible massive accident if you mess up.

 

I have no fear of using taps and/or dies as I've experience doing that, just never used a helicoil.  I think the challenge would be drilling a straight hole; I don't know how I'd make certain of achieving that.

 

Only just got a chance to price things up; a helicoil kit will cost me about the same as a s/h hub, so I might as well just get down the scrappy.

 

Cheers for the advice lads, tune in tomorrow to find out how much worse I can make it.

[dieselassist]

...find some poor sap breaking one of these, locally, n do a snag list on your own car before heading off to his/hers, n get the chap to 'bundle price' whatever parts you need...

 

 

over here, there is virtually no value these days in mk4 golf parts; especially the front hubs which are a poor design (one bolt clamping the strut to the hub, if it isn't torqued up to 'MEGA' Nm it can slip down the hubs collar n destroy the outer CV) ; it hard even to give such a part away, Ive found - they are so common here, n so few folk 'sticking with' the mk4 at this stage if its a 1.4/1.6 petrol... the rear calipers, when both are working right, are about the only parts that command any money as they are an upgrade for mk2/3 GTi's...

[ruffgeezer]

There is a specific repair kit for such situations;

 

http://www.cartoolstore.co.uk/trident-16-piece-brake-caliper-thread-repair-kit-m9-x-1-25mm-t411600

 

 

It works by drilling the mashed threads out and then installing the insert from the other side of the hole so it cannot be pulled through on the slider.

 

You may have to clearance the back of the pad a little to allow for the extra thickness, but at this level of mingebaggery, it's a small price to pay.

 

Given the option get a good, used hub.

[Barry Cade]

Had this issue a few times, Octavia's have the same issue and taxi's go through lots of pads so a common fault. Used the kit in the pic and was as good as new, cost under 20 quid from local factors

 

http://i.ebayimg.com/00/s/MTE4MVgxMTY2/z/HGYAAOSwR0JUQUfY/$_57.JPG?set_id=880000500F

[DaveAspley]

Ceri, give sanburns vw breakers a ring, they are by the Rich arena. A secondhand hub won't cost the earth and takes an hour tops to change.

I've had the same thing happen with the Octavia taxis here, no point pissing around sometimes you've got to bite the bullet and get it fixed.

[Richard]

Does an Octavia hub fit? I imagine they are much more plentiful in breakers.

 

It sounds as if an Ocap/Firstline/Bolk replacement part, if one exists, might be considerably better quality than the original.

[worldofceri]

A secondhand hub won't cost the earth and takes an hour tops to change.

 

Haha!  For you maybe!

 

Thanks for the info Dave, I was going to try them anyway as the car is at my Mum's - on the same road as them - I can take a stroll down!

 

Thinking about it, I haven't dismantled the nearside yet, so I think I'll do that first to make sure I don't have the same problem that side.  Apparently over-tightening of the bolts previously can give rise to the problem, so I'll make sure I don't need two new hubs first.  Plus, if it goes well I'll have more enthusiasm for tackling a hub-change.

[Guest Hooli]

Slightly O/T a T45 torx driver undoes those allen bolts perfectly (If they are the same as a '59 Caddy*).

 

 

 

 

 

*Not the nice ones no.

[steveo3002]

dunno about your area but theres guys that go around fixing stuff like this ...thread doctor and the like , might be worth a google

[TataBobu]

Nobody rethreads using taps anymore? I'm talking about this type of tools.

[Guest Hooli]

Nobody rethreads using taps anymore? I'm talking about this type of tools.

 

No good when you need the same size hole you started with because the 'bolt' that goes in it has a totally smooth outside circumference as it forms the slider for the calliper. Unless of course you weld the hole up & redrill it, which is more effort than a helicoil.