Front brakes safety wiring

[Philippe-J.]

Gentlemen,

the front calipers are secured to the stub axle carrier with 4 bots (C26932), of different lengths. According to the Bentley's manual, they should be safety wired. On my car, not only the wires have disappeared, but one of the 4 bolts has no holes in its head, so can not be wired. Is this standard, or should I dig a hole, as in the 3 others, prior to reassembling?
Where can I find a picture of the final wiring?

Thanks.

[mgcjag]

You should be useing the correct bolts and safety wireing...have a look here viewtopic.php?f=3&t=19572

[Philippe-J.]

Thank you Steeve. I already know this thread about safety wiring. I was asking in the case of the front brakes, if there is a photo of their wiring geometry.
As long as the bolts are concerned, you're right, I should not ask myself questions. As soon as one bolt is suspect, I should change the lot, without trying to identify and assess which is right and which is not. Obviously one PO was not rigorous enough, even with such a safety item

[Philippe-J.]

Hum... maybe I found an indication in the following photo, taken from a recent listing on BaT:

In this image one can see that only 3 bolts are wired together. The lower front one is free. That is in line with the bolt configuration I found on my car, the latter bolt being not drilled (but I am missing the wires, apart a bit of one).
Do you confirm that the photographed configuration is correct with respect to the safety wiring?

[AshM]

Here you go Philippe.

You should definitely ensure you have the correct strength bolts and they must be wired.

[bitsobrits]

It's only the caliper bolts that need wired, and AshM provides an excellent example of how to do so.

[Philippe-J.]

Thank you all for the wiring explanations.
Now, about my bolt strength grade. I took a photo of them:



3 are from BAX, the 4th and shorter is GKN, all are S or "'5" graded. As far as I can see on the photo of SNG's listing, this is correct (though it is quite odd that this spec is not clearly written for such a key item). Can you confirm this is the correct grade to secure the brake calipers?

Regards.

[Philippe-J.]

Finally the rationale for the front brake safety wiring is quite obvious when looking at the inner side of the hub carrier:



The RHS lower bolt (on the image) does not hold anything but the brake mud shield (black), so it does not need to be wired. That's why it has no hole in its head on my car. The two LHS bolts secure the caliper, and the upper RHS secures the steering arm. That's why they do need to be wired, following the red lines above, even if they have spring washers under their heads.

It sounds all logical, doesn't it?

[mgcjag]

Yes...correct..Steve

[Phil P]

Forth bolt is not safety wired.
Has anyone experienced spreading of the fork attachments of the brake shields?
I found that the forks were spreading and ended up with the washers cupped. I solved it by using high tensile washers.... seen as dark grey in the photo.
Phil

[Philippe-J.]

As a matter of fact I found the forks slightly spread when I dismounted my car. Nothing serious but your solution seems to be on the safe side. Where did you get those high tensile washers?
BTW thanks for your photo, it clearly illustrates the proper safety wiring of the 3 bolts.

Philippe

[Phil P]

Hi Philippe,
The washers were from Spalding Fasteners, Lincoln, UK but actually bought through their eBay site to avoid postage as I only wanted a small quantity. I'd give them a call.

The description of washers are Grade 10.9 high Tensile Steel, Through Hardened Flat Washers to DIN6916.

The spares catalogue shows the part number to be C.24844 which isn't available at SNGB or Robey's. As it's a Jaguar part number and not a standard part, I suspect that this in fact may have been a high tensile part originally or perhaps thicker than standard.

I think that the spring washer having a smaller diameter than the washer probably contributed to the cupping effect where it was unsupported by the shield fork.

I Hope you get on OK.
Yours,
Phil