Skoda Fabia 2 1.4tdi hub carrier

[Togston]

Just wondering if anyone can advise me on whether a hub carrier from a 1.2 petrol will be the same as my 1.4 tdi, some garage before i purchased it has over tightened one of the caliper bolts and i now need another carrier, I've found a good used one but its from a 2010 1.2 petrol. Looks identical from the pics but just wondering if anyone can confirm that I'm right ?

 

Cheers in advance 

[Breezy_Pete]

Depends on whether the 1.2 had 256mm disc brakes, like yours I expect, or 239mm in which case no good.

 

Various options exist for the repairing those threads. I think a fella called @mrgf explored this territory fairly recently and successfully.

[KeithCheetham]

If you are referring to the caliper slide pins.

Edited 19 October, 2020 by KeithCheetham

[Togston]

Ah I thing I have Spot my issue, I tried to repair via a helicoil kit but I measured the threads as M8 to which the bolt would fit the new thread, are these Bolts M9s ? 

[Breezy_Pete]

Yes, I believe they are.

 

And that makes me realise another difference between the hub carrier parts that suit 256mm and 239mm brake set-ups.

The suffix-AC and -AG & -T parts here respectively: https://skoda.7zap.com/en/cz/fabia/fab/2010-608/4/407-407011/

 

On 239mm set-up there are actual bolts holding the calipers on, through steel 'guide sleeves', and those bolts - items 4 &5 - are M8 (6mm hex bit to undo). https://skoda.7zap.com/en/cz/fabia/fab/2010-608/6/615-615015/

 

On 256mm there are guide pins - items 2, 3 - instead, which are the ones with the M9 thread (7mm hex bit to undo): https://skoda.7zap.com/en/cz/fabia/fab/2010-608/6/615-615016/

 

So the threads will be M9 on the -AC hub carriers and M8 on the -AG & -T, as well as the pad carrier bits being a bit further out on the 256mm.

 

Anyone know what the difference is between 1LB and 1LM 239mm brake PR codes?

Edited 19 October, 2020 by Wino

[mrgf]

Togston, if you look at the thread/post I created, there are two types of tool... One has a drill bit larger then standard and then, thicker threaded caliper pins. (Same outside diameter). The other has a smaller drill bit, screw-in inserts and then you re-fit your standard (M9) sized caliper pins. I used the later, thinking if ever I had that new thread strip, I could always either try a new insert or get the other tool, and have thicker (M10) Threaded caliper pins.

 

Also, I found a supplier who had such a competitive price, it was around half the price of the replacement pins. The supplier is named in the thread/post so should be really easy to find. 

 

There is an eBay  seller who has also listed a newer, lower price of only £13, delivered, along with a basic guide to use the tool so better still!

Edited 19 October, 2020 by mrgf

[spartacus68]

If it were me I'd be opting for a new or salvage hub carrier, no question. I've used helicoils before on a suspension strut (1 of 3 bolts) and steel insert on a spark plug insert, but this is for the brakes, hence ponder the consequences if it fails.

 

Rather than over-tightening the caliper bolts, suspect it's been cross-threaded originally, then when tightened its stripped it. Not much use now, but **** happens.

[sepulchrave]

40 minutes ago, spartacus68 said:

If it were me I'd be opting for a new or salvage hub carrier, no question. I've used helicoils before on a suspension strut (1 of 3 bolts) and steel insert on a spark plug insert, but this is for the brakes, hence ponder the consequences if it fails.

 

Rather than over-tightening the caliper bolts, suspect it's been cross-threaded originally, then when tightened its stripped it. Not much use now, but **** happens.

 

Scaremongering makes no sense, I've used high tensile steel wire inserts (helicoils) my entire professional life and I can categorically state that when used and installed correctly they are stronger than the material they're replacing.

 

You don't know what you're talking about.

In engineering **** does NOT just happen, **** happens for a reason, in this particular case there is no reason for your statement whatsoever.

[mrgf]

With respect, I agree with Sepulchrave... The inserts I recommended and used, fit into a tight hole, with threadlock and actually go in th opposite side of the hole so as to be damn well near impossible to pull right through. The threads would strip first and the pin would pull out the thread and this is more likely in the cast metal, then the stainless insert! I would worry MORE about using a Helicoil insert on a spark plug, which if failed, would knack the engine, then the unlikely event of one of these brake pin inserts failing. If you actually look at the rotating force of the brake disc against the steel pin and see how slim the pin is, then think of the weight of the car and the speed it may be travelling, you would think the brakes are going to fail every time they are applied but they don't!

 

Any company selling these tools/kits would be liable for a massive lawsuit if they were failing and causing accidents/deaths. They are designed, tried and tested and allowed to be used. I would also worry more about a used steering knuckle from a salvage car as the vehicle may have travelled many miles and been on the road for years, with no way of knowing the provenance of the part fitted. (And I don't worry much about that)!

Edited 22 October, 2020 by mrgf

[Breezy_Pete]

The slide/guide pins don't take the rotational forces, it's the edges of the pad backplates resting against the sitcky-outy prongy bits of the bearing housing that do that, as far as I can see.

[mrgf]

You could be right but when you remove the pins, you can then remove the caliper so they must be under some sort of force when braking...

The pins go through the caliper, in to the knuckle so they must prevent the caliper from being "Thrown" Off the knuckle.

[KeithCheetham]

 The force would be a shear across the pin, with the greatest force across the threaded to plain portion interface which will have an undercut to allow the plain portion shoulder to abut against the carrier - if they were to take any loading. The pins and holes in the caliper are toleranced, with the caliper pin holes and carrier tapping centres also toleranced to give a slight clearance allowing axial movement, i.e. caliper towards or away from the disc.

 What actually happens is the pads "hook" into the carrier when fitting so will take the rotational force from the pad to disc frictional action directly into the carrier - the caliper does not move, the pad will move slightly over the piston face until contacting the carrier.

[sepulchrave]

2 hours ago, mrgf said:

You could be right but when you remove the pins, you can then remove the caliper so they must be under some sort of force when braking...

The pins go through the caliper, in to the knuckle so they must prevent the caliper from being "Thrown" Off the knuckle.

 

You can remove the caliper leaving the pads in the carrier, there is no force on those pins, they're simply guides to keep the caliper in the correct plane, the caliper is effectively floating.

This argument is bringing no light to the matter, only heat, the OP can repair the threads easily using a 9mm thread repair kit for a fraction of the cost in a fraction of the time.

[mrgf]

The funny thing there is, I am in accord when it comes to using these kits... The point I made seems to be overlooked by what may or may to be technical/physical forces on the pins and not that I disagreed with Spartacus66's suggestion of fitting a used part over and above using the kit. I still stand by my post stating the pins must prevent the caliber from being thrown off, even if my technical description was flawed. To that, they MUST take some stress/strain. But I digress... 

 

To the OP, Togston, the tool/kit is most likely exactly what you need and is much easier to do the job, then removing/refitting the whole knuckle. If I managed it and you can use a socket set and drill, along with jacking equipment, so can you. Good luck.

[spartacus68]

Found this on YouTube. He's making a bit of a hash of it, no oil on the drill bit, attacking with high revs on the drill rather than slowly does it. Key point if you're going to use a helicoil is it goes in at the correct angle when you're drilling. This is a floating caliper, so if the brake slider is even a little skewed, you'll get issues down the line with sticking caliper and pads heating up.

 

Reference earlier comment on a solid steel insert, did this on an outboard engine. The steel insert is stronger than the surrounding alloy on cylinder head. Anyway, hope the op gets it fixed.

 

https://m.youtube.com/watch?v=IX9NNkUdPl8