Update on Twinkle's (our Ibiza) front caliper slide pin.

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Update on Twinkle's (our Ibiza) front caliper slide pin.

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It's service time again for the Ibiza - slightly over actually - and this time, in addition to all the stuff like oil changing, groveling around in the passenger footwell renewing the pollen filter and other such "jolly japes" I decided to really give the brakes a going over in more depth than usual. Those of you who hang around on the forum may have read a previous post i made, maybe a year or so ago, about the lower slide pin on the N/S front caliper almost giving me heart failure as it largely destroyed it's thread as I removed it. This actually happened on the first service I gave it once it was out of warranty which I did in Feb '20. By very carefully aligning the slider pin with it's hole I was able to pick up enough thread to get it nicely retightened but I just knew it wouldn't do it again. Then last year, because we'd done next to no mileage with it (covid etc) I decided to "time shift" the servicing to the summer months to take advantage of the better weather. Sure enough the pin, although it did go back in, was far from being properly secure, so I drove it round to one of the 3 VAG independents in Edinburgh and he installed a threaded sleeve which has completely cured the problem. He used this kit: https://www.lasertools.co.uk/Product/5037/Brake-Caliper-Guide-Thread-Repair-Kit and I have to say the outcome has been very good indeed. There are loads of cheaper options on Ebay, this one seems to get a good crit: https://www.ebay.co.uk/itm/25230538...9jkqwLaI1UwqEuaL+tOxJF9SWg==|tkp:BFBMtOroi71g and would probably be the one I'd buy - or the very similar Sealey offering. If you look closely at the business end of the drill you can see it has a short reduced diameter length then it widens out to the larger diameter. This short end is used to "ream out" the damaged thread and then the larger diameter cuts a recess in the casting for the shoulder of the insert to locate in. A smear of locktite on the insert and "Bob's your Auntie"

Here's the caliper carrier on the Ibiza with the insert in the bottom hole:

P1100359.JPG


Here's a close up of it:

P1100357.JPG


In fact if you look at the other side of the thread you can see the threaded insert isn't fully home:

P1100358.JPG


This is because he's not cut the recess for the shoulder of the insert deep enough. When I first saw this yesterday, when I removed the slider pin, I did feel a little disappointed but now I've had time to think it over i think it's actually not a bad idea. The threaded portion of the pin is more than long enough to get a very good secure hold in the hole and, thinking about it, there's not a lot of "Meat" around that bit of the casting. Fully recessing the sleeve would entail taking out a fair bit more metal to accommodate the top shoulder thus potentially weakening this wee bit of casting even more. So, I'm very happy to live with it as it is.
 
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As an addition to the post above about the slider pin repair I thought I'd add in this about the Ibiza's brakes as I found them during this annual service refurbishment. The first thing I have to say is I don't like the design of that front hub assembly. The caliper carrier is all one piece with the entire hub casting:

P1100358.JPG


It's integral with the main hub casting, not bolted on like our Fiat ones. This is fine until you do something "horrifable" to the threads or even break a bit of the casting. With the Fiat it's just going to be a visit to the scrappy to get another carrier. On this it's going to be an entire hub assembly! Daft eh? still it's probably saving then a couple of bob at manufacture. I also think that considering that wee bit of casting is retaining the caliper to the hub, it's a bit on the mean side dimension wise?

Anyway, I'd been slightly - no, let's be honest - absolutely bricking, taking that slider pin out after all the previous agro it had given me. Needn't have worried though it came out easily and the thread is "perfect".

The car is now just going into it's 7th year of life but only got 26,000 miles on the clock. The only real drama we've had was when she had to have a new turbo in her 2nd year. Luckily replaced with an updated version free of charge under warranty (there was a turbo wastegate actuator linkage fault on the early models and, of course, ours was one of the last built with the old linkage!)

The front disks are looking not too bad, no deep scores etc and now measuring 20.54mm thick (acceptable range 22 to 19mm) so about half done. They are slightly worse on their inner faces but not significantly so. The pads too are looking good. Here they are on my bit of plate glass and a sheet of emery which I use to glaze bust:

P1100361.JPG


Don't know what their new thickness was but they now have 9mm and are recommended for changing at 2mm - I'll change when they get near the 3mm as I don't like running pads down to the limit. Looks like pads and disks will be about due together at this rate of wear.

One thing you have to watch for when reassembling, or for that matter when stripping down, is this wee locating protrusion on the bottom of the caliper:

P1100363.JPG


It's very easy not to see it and I nearly broke it off first time I removed the caliper by getting too physical when the caliper appeared to be "stuck". You have to pull the top of the caliper forward and then lift up to disengage it. When reassembling of course it has to go in first. Did you notice the unusual clip arrangement on the back of both pads? (last picture but one) the pads, both inner and outer, clip into the caliper itself and when you go to refit the caliper to the carrier these clips try to push the entire caliper forward. You have to lean pretty forcefully against then to get the slider pins to line up with their threads in the hub. The garage told me it's not all that unusual to see damaged pins/threads due to someone not lining this up and cross threading it. Honest Gov, not what I did.

Here it is all ready to go for another year, I hope. next year it may be disks and pads just to give me another work out!

P1100364.JPG


The O/S was very similar except that I'd recently been hearing a slight squeal from it when braking lightly so wasn't surprised to find the inner pad partially seized to the caliper. An easy job to clean it up and it was all ready to go again.

Next it was on to the rears. The outer faces were pretty good for rear disks. Don't know about you all but I dislike rear disks on "every day" motors. In my opinion drums are much better in that you usually get a better hand brake action and they don't corrode horribly due to exposure to all the road crud which gets thrown up at rear brakes - anyway they have much less work to do than the fronts - which may be part of the corrosion story where rear disks are concerned. But enough of that for now. I was frankly surprised to see how well these rears have done. The outer surfaces were pretty good:

P1100365.JPG


and the inners, often where most wear/corrosion takes place, weren't all that bad either:

P1100369.JPG


Notice the bolted on caliper carrier? pray do tell me, why can't they just have done the same on the fronts? This is actually the worst of the two, the one on the other side is slightly better but the sun wouldn't let me get a picture of it. And the pads? well, not bad actually:

P1100367.JPG


With 7.5 to 8mm remaining I'll definitely get another service interval out of them. By next year I think the rear disc inner faces will be too bad to continue though so I'll probably just do the lot then. going on 8 years old by then? probably a good idea to change at this age anyway as stuff like bonding and resins will be getting suspect maybe?

Interestingly, or not? the oil came in a "wine box" this year:

P1100372.JPG


Wasn't expecting that as the add showed it in a container like last year's - here on the left. I didn't get on with pouring it very well so I decanted it into last year's container and that was much better - think I'll be hanging on to that old container for a while!

Just realized I've got one image left i didn't use (no idea why this is coming out initalics- must have pressed something? Anyway, here it is and I took it to illustrate the "spindly" nature of the cast arms on the front hub which are what's actually taking all the braking forces from the pads. Like most disc brake setups, the caliper is only doing the "squeezing" they don't resist the turning of the road wheel:

P1100362.JPG


You'll have gathered I'm not a great fan of this front brake setup! Must try to cancel those italics now, Bye folks.
 
Last edited:
To get rid of text formatting, Select and Cut the offending text, then use "Paste Special" and choose "unformatted text".

I often use Notepad to cancel text formatting. Switch to Notepad, paste in the formatted text and cut it out again. Switch back to your original job and paste your text. All formats will be gone.
 
To get rid of text formatting, Select and Cut the offending text, then use "Paste Special" and choose "unformatted text".

I often use Notepad to cancel text formatting. Switch to Notepad, paste in the formatted text and cut it out again. Switch back to your original job and paste your text. All formats will be gone.
Thanks Dave, but i only understood about a quarter of that. I just followed the age old remedy of switch off and switch on again and what do you know? italics gone! that'll do me.
 
Thanks Dave, but i only understood about a quarter of that. I just followed the age old remedy of switch off and switch on again and what do you know? italics gone! that'll do me.
With regard to italics:
At the top of the little box you write in, you'll see something that looks a bit like "B I tT : -- --".
The second one in is italics. Press it to switch to italics, press again to turn off.
The first one is bold. press on, press off.
Then you've got font size. etc etc

Place your mouse over them, and they will tell you their function.
 
With regard to italics:
At the top of the little box you write in, you'll see something that looks a bit like "B I tT : -- --".
The second one in is italics. Press it to switch to italics, press again to turn off.
The first one is bold. press on, press off.
Then you've got font size. etc etc

Place your mouse over them, and they will tell you their function.
Aah, all is becoming clear grasshopper. I discovered how to use the attach files to embed images from my pictures files but never really bothered looking at anything else. Thanks.
 
You can individually switch the text attributes e.g. Ctrl + I = italics, Ctrl + b = bold, Ctrl + u = underline. But when there's loads of them, just block copy the text into a basic test editor like Notepad. Now cut or copy that text to your original document and its lost all formatting. You can also use Edit - Paste Special, but that's more faff than switching to the notepad app and back again.

Windows, Alt-Tab is a fast reliable switch between the apps you have running. Alt-Tab a few times until the one you want is on top. Alt-Tab once more, puts you back at your original app. On a Mac, Cmd-Tab does the same thing, which I suspect is where Microsoft got the idea.

Another handy shortcut is Ctrl + x, c or v to Cut, Copy or Paste the highlighted text. It's so much easier than scraping away with the mouse.
 
Hi all,

I am enjoying seeing the tread repair insert being fitted from the "wrong" side . much easier to drill and tap from outside of wheel well plus as Jock pointed out probably results a stronger repair. I will endeavour to remember that trick.
That front brake set up is by ATE , there are chunky rubber bushes in the caliper which the slide pins go through. So if there is a small misalignment following thread repair all will still be good.
Thanks for the photos and posts Jock.
Best wishes
Jack
 
I had to do similar with a golf front caliper, and just bought the helicoil kit, drilled, tapped and then had to trim the helicoil as it was longer than the metal. It felt solid after that, never had any issue with it.
 
Hi all,

I am enjoying seeing the tread repair insert being fitted from the "wrong" side . much easier to drill and tap from outside of wheel well plus as Jock pointed out probably results a stronger repair. I will endeavour to remember that trick.
That front brake set up is by ATE , there are chunky rubber bushes in the caliper which the slide pins go through. So if there is a small misalignment following thread repair all will still be good.
Thanks for the photos and posts Jock.
Best wishes
Jack
Good day Jack. Hope you are keeping well what with the covid and high temperatures etc.

Unlike a helicoil, which could be installed from either side as this is a "through" hole (but, if using a helicoil, I'd prefer to install it from "inside" - that is to say the engine side - because of the fact you have to break off the driving tang which might result in a slight deformation of the end of the insert thus making it, possibly, slightly more difficult to start the slide pin into it's thread if the insert is installed from the "disc side" of the casting as it would be starting into the, possibly deformed thread end?) The type of insert used here has a shoulder so, as the slider pin is inserted from the "inside" (engine side) the insert itself is installed from the "outside" - as can be seen in the pictures - so the tighter you do up the slider pin the more it "snugs" the shoulder into the casting.

You make a good point about the rubber bushings. Unlike many setups of this type which I've come across, the pins do not slide in metal bushings. Indeed the rear calipers on this very car are of that type. So the front sliders I lube with silicon grease whereas the type which slide in metal bushing I would choose Moly grease. - which, of course, if used on the rubber bushing would result in degradation of the rubber.

Because of those, really quite strong, spring clips on the pads trying to pull the caliper out of alignment whilst you're trying to fit the slider pins, it's a little difficult to feel when the slider pins are entering the female thread without cross threading. The fact you are "wrestling" to slightly compress the spring clips with one hand as you try to enter the slider squarely into it's thread with the other hand makes it a wee bit more difficult. Due to that wee projection on the bottom of the caliper having to be engaged behind the bottom pad rest before you try to put either slider pin in I find it best to enter the bottom slider pin first - which goes in quite easily - then use the bottom pin as a sort of fulcrum to pivot the top of the caliper, thus compressing the pad spring clips, until it's slider pin can be started into it's thread. I also find it makes it easier if the piston is pushed well back into the caliper as this allows you to wiggle and jiggle the caliper around to a greater extent - Remember the pads are "prefitted" to the caliper due to the spring clips so there's only limited "wiggling" possible between the caliper and pads as you're fitting the slider pins.

I've come across calipers where the pad on the piston side is retained to the piston with a spring clip which goes inside the hollow piston - as with this one - but I've not previously come across one where both pads are retained to the caliper with clips of this type - and thus have to be prefitted to the caliper before assembling the caliper to the carrier/hub. I found it quite difficult to get the pins lined up the first time I did it (some 2 years ago) but there may have been a "panic" factor in that because I'd just discovered the damage to the thread of that bottom pin. This time round I found it much easier and it didn't really give me any problems - although I'd been "worrying" about it for some time before actually doing it.
 
I had to do similar with a golf front caliper, and just bought the helicoil kit, drilled, tapped and then had to trim the helicoil as it was longer than the metal. It felt solid after that, never had any issue with it.
Another entirely satisfactory way to do the job. Back in college in the 60's our fitting instructor was very keen on thread repair options. - and very glad I am that he was as it's stood me in good stead during my working life. We did lots of exercises involving screw extractors. Tapping round with centre punches. Welding nuts onto broken studs. Drilling out to oversizes and retapping then using a larger diameter fixing which had to be hand filed flush before drilling to the original diameter, tapping a new original size thread so you can put a new original size stud back in and so on and so on. Then, one day, he produced the Helicoil kit and we all got to practice, (just one each mind you, these things are expensive he said!) I really discouvered about Helicoils when I "got into" Hillman Imps. I helicoiled all the head stud holes in the block on the second engine I built and never suffered a head gasket problem. Helicoils are so commonly used for thread repairs that it's become a term used in much the same way as "Hoovering" has to Vacuum cleaners. I like them a lot and they are easy to procure and relatively cheap, however I think I have a slight preference for inserts like "Time Serts" if money is no object.

Years ago I was fortunate enough to come across a spark plug Helicoil kit at an Autojumble. Anyone up this way remember the excellent one that used to be held in Musselburgh Town Hall? I was always very aware of stripping spark plug threads in ally heads after working on the wee 2 cylinder DAFs which used short reach plugs. So when I saw this kit on his bench I just knew I had to have it and he sold it to me for a very reasonable amount. Here it is complete with both the roughing and finishing taps and two sizes of inserts for 14mm plugs along with the inserting tool which makes it much easier to actually install the insert into it's new home as it slightly squeezes (reduces the diameter) of the insert as it is wound through the tool:

P1100396.JPG


P1100392.JPG


Cheaper kits don't include this inserting tool which is Ok with smaller diameter inserts but not so easy with larger diameters like spark plugs. The drill, and the tap on the right hand side I added to the kit. The drill cuts the original size hole out to accept the taps for the insert and the small tap on the right is actually for thread correction if you just have a slightly damaged original thread that needs cleaned up - typically if someone has cross threaded and just damaged the first thread or two but the remainder are fine.

In fact it's really come into it's own with my "hobby" interest in old horticultural machinery. Most of these machines are powered by simple sidevalve engines like the common Briggs and Stratton or Tecumseh you see on so many lawnmowers to this day. Most of these side valve engines only need a thin depth of metal on their cylinder heads (no valves in the head) so use short reach plugs. Stuff like strimmers/brush cutters, hedge cutters and the like also use very short reach plugs so guess what? your average, pretty ham fisted, horticulturalist, whilest being very good and knowledgeable about their plants - wish I knew half as much - turns out to be very good at overtightening and thus stripping short reach spark plug hole threads!

You'll have noticed I've arranged some example plugs for you to see:

P1100393.JPG


Starting on the right the first one is a "bantam" plug which I come across a lot in stuff like strimmers, hedgecutters, leaf blowers, etc. Next in is just a standard mower plug from a Briggs and is very common in mowers and stuff a little bigger than strimmers and hedge cutters, sometimes they are found in the smaller machines too. The third one in is actually a new plug for my old DAF33 which I never got round to fitting! You can see all three of these are accommodated for by the short insert. The next 3 are standard length plugs taken from the family vehicles over the years. They are a very common size and all catered for by the next longer size of insert. These are the only sizes I've bought so far and I've been able to rectify the defective threads I've come across so far with just these 2 sizes. However, look at that chap on the left. He's a bit longer isn't he? This seems to be the trend now. I suppose there's so much "stuff" fighting for space in the average head now - over head valves, fuel injectors, "fancy shaped" porting to induce swirl, and the plugs and individual coil packs that they are having to "bury" the plugs ever more deeply into the heads to have access to the combustion chamber, so they're getting longer! Access often isn't too good so I'm glad I've not had to tackle one yet. In fact I remember doing one on a Peugeot 504 many years ago - anyone remember them? I had to buy a special extra long plug socket to get to the plugs. Naw, don't think I'll take one of the modern ones on!
 
The golf had a weird size on the guide threads, M9!!, so I have a specific M9 helicoil kit that I'll probably never use again, was still cheaper than a new hub carrier.

Didn't realise you could helicoil spark plugs, that is good to know. Though always start a plug going in with no ratchet handle to avoid cross threading.
 
The golf had a weird size on the guide threads, M9!!, so I have a specific M9 helicoil kit that I'll probably never use again, was still cheaper than a new hub carrier.

Didn't realise you could helicoil spark plugs, that is good to know. Though always start a plug going in with no ratchet handle to avoid cross threading.
VAG seems to be continuing this "trend" because I noticed the thread size on the Ibiza's slider pins was an uncommon size - can't quite remember, think it was the same as your's ie. a 9mm but it might have been 7mm? whatever, it was one not commonly found. Oh, hang on though, isn't the Allen key which fits the slider pin a 7mm? so probably the thread is a 9mm.
 
The golf had a weird size on the guide threads, M9!!, so I have a specific M9 helicoil kit that I'll probably never use again, was still cheaper than a new hub carrier.

Didn't realise you could helicoil spark plugs, that is good to know. Though always start a plug going in with no ratchet handle to avoid cross threading.
Absolutely to always wind a new plug into it's thread by "finger power" to avoid cross threading.

Regarding helicoiling spark plug holes. These are quite "big" holes and the most difficult bits I find are drilling out the hole with that big drill and getting the new insert to install without "jumping" threads as you wind it in. The installation tool helps a lot with the latter and a nice big fairly heavy drill - so it's got a bit of inertia - running at slow speed with your body braced firmly against something, helps with the former. If the drill picks up though it can really give you a "kick! I've tried using the drill in a tap wrench and winding it in like you would tap a hole but it doesn't really work and takes "forever". I also set the piston at TDC compression to close the valves and coat the end of the drill with HMP grease then take multiple light cuts with the drill so that most of the swarf is picked up in the grease and comes away with the drill. You have to do this multiple times, recoating the drill tip every time. Then, when the hole is drilled out, I have a length of brake pipe with an old car tyre valve J B Welded to the end so I can connect it to my air line, stick the tube right inside the cylinder and blow it all out with compressed air in the hope that any little bits that have fallen in may be blown out. I think it probably works as I've not had any problems with subsequent engine failures/low compression etc. That "trick" of coating drills, and especially taps, works well when rectifying stripped out sump plug holes. Last thing you want is little bits of metal swilling about in the sump!

What a lot of people don't realize about Helicoils is that the diameter of the insert is considerably larger than the diameter of the hole you're trying to wind it into - which, of course, you've prepared by drilling out and rethreading the damaged hole using the special Helicoil taps. This is so that the "springy" insert, once installed, is pressing outwards against the parent metal very strongly and this should then prevent the insert from unwinding from the hole next time you remove the spark plug or bolt or stud or whatever. Of course don't forget you're making a bigger hole in your engine block or whatever when doing this process and it's just possible you may break through into a coolant or oil gallery. If it's something like a stud which is going back into the hole I often apply something like Loctite as a bit of "backup insurance" - of course you can't do that with a spark plug, but I've never had a problem like that with one either.
 
I've read (and belive it) that helicoil threads are stronger than the original, since it's made of hardened steel and has a bigger thread in the old material
 
I agree re rear drums in preference to discs Jock. My preferred option is what I have on my Skoda Scout and all the old Iveco Daily's I had, discs all round for ease of changing brake pads, but a brake drum in the centre of the rear discs for a good handbrake. When Citroen first went to discs for the handbrake there was a spate of cars rolling away due to parking hot on a hill, the disc cooled and contracted and the handbrake relaxed;) I assume that is what brought forward electronic hand brakes for discs to give max pressure at all times. Though a pain to change the pads without an electronic tool!
 
I've read (and belive it) that helicoil threads are stronger than the original, since it's made of hardened steel and has a bigger thread in the old material
When I first got deeply into Hillman Imps I was a regular attender (spectator only) at hillclimbs (Doune is easily accessible for me). there are some indecently quick Imps to be seen at hillclimb meetings. Of course I got speaking to the owners and one of the "fascinating" facts I gleaned was that they Wills ring the heads and automatically helicoil the blocks even if they don't have any known thread problems. They also slightly recess the holes in the block so that the first thread is slightly below the deck face so that "thread pull" doesn't result in the edges of the hole "pulling" up proud of the deck face when the head is torqued down - which would, of course, reduce the "crush" effect of the head to the block.

Try you tubing "Hillclimb Imps" for more thrills.
 
Though a pain to change the pads without an electronic tool!
I've done loads of rear disc handbrakes, never had to use an electric tool, a £10 chinese copy rewind tool has done the job every time. Though before that it was a fight with long nose pliers.

Drum brakes are a pain, usually involves swearing at various springs, and needing 3 pairs of hands to hold things.
 
I've done loads of rear disc handbrakes, never had to use an electric tool, a £10 chinese copy rewind tool has done the job every time. Though before that it was a fight with long nose pliers.

Drum brakes are a pain, usually involves swearing at various springs, and needing 3 pairs of hands to hold things.
I'll agree with you that manually actuated disc rears are easy to service and change pads on - as long as the caliper is in good order. Where it all starts to go pear shaped in my experience is when there's a problem with the caliper and it won't wind back due to piston corrosion or other problem. Both the earlier Fabias my boy ran had big problems with rear calipers and especially with the lever arms not returning fully, and it wasn't anything to do with cables. On the first one I renewed both calipers at considerable cost. The second one responded to fitting the return springs intended for the Sharan/Galaxy. So far the Ibiza is behaving itself but I see it would probably be possible to fit these springs to it if needed. Sorting out drums is more labour intensive but usually so very much cheaper if you're not paying labour.

I can't talk with any authority about electrically driven hand brakes as I have very little experience of them, and don't plan to acquire a car with an electric hand brake until it's forced upon me! But to do them, on the VAG stuff anyway (which are the only ones I know anything off) you need to be able to electronically intervene - with something like Vag Com/VCDS - to wind back and immobilize the hand brake actuator, Oh, and count your fingers when you're finished!
 
The citroen electric hand brake is just like a manual one, there's a big motor unit in the spare wheel well that pulls the cable like the old handbrake.

My brother had an A5, and left me confused at first looking for the handbrake cable. The new vag ones with motor on the caliper are easy to do too. 12v battery on the connector rewinds it then use the tool. The electronics have a fit when you start the car, but once it's operated twice it's all good again.
 
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