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Brake line T attachment - must it penetrate all the way through?

ElmrPhD - 12/10/12 at 01:17 PM

I read somewhere that someone failed IVA because they attached the brake t to the chassis tube with merely a rivnut or something. The official problem was that all attachments to brake parts must have a locking mechanism. This victim said that he was instructed to drill all the way through both walls of the chassis tube in order to be able to fit a locking nut (or safety wire or something) on the attachment bolt.
Anybody know of a clever way to make the IVA happy without piercing both walls of that chassis tube??? I plan to beat the poo out of this car and would hate to see the chassis crack because some official thought it was safer to damage the tube with a through-bolt.
Thanks for any good ideas!
Steve, in the NLs

me! - 12/10/12 at 01:23 PM

Weld a tab on the chassis and bolt it to that?

mikeb - 12/10/12 at 01:33 PM

I've read the same thing for IVA.

I've got one rivnutted that I'll need to drill through, its only a 6mm hole in the 25mm tube so should be ok

loggyboy - 12/10/12 at 01:41 PM

I plan on using threadlock and torque seal paint on mine which are rivnutted:

ElmrPhD - 12/10/12 at 01:58 PM

Hi Loggyboy,

I think the victim/complainer was saying that "I put Loctite on it!" was not sufficient for the IVA dude.

Thanks for the pic though!

SteveE, in the NLs

adithorp - 12/10/12 at 01:59 PM

mine are on rivnuts but I went through SVA. Don't recall seeing any failures for this.

You could use a rivnut, screw a stud into the rivnut then secure the T with a nylock nut. Would look like a stud welded to the chassis.

loggyboy - 12/10/12 at 02:00 PM

quote:
Originally posted by ElmrPhD
Hi Loggyboy,

I think the victim/complainer was saying that "I put Loctite on it!" was not sufficient for the IVA dude.

Thanks for the pic though!

SteveE, in the NLs

But I will be taking photos of me loc'ing them and adding the torque paint

Bluemoon - 12/10/12 at 04:25 PM

Used "proper" break-clips rather than P clips as used on a production car?? This is what I did dor the SVA.

theprisioner - 12/10/12 at 05:58 PM

After reading this thread I was horrified about the thought of drilling the 1" tube all the way through. I am not keen on a welded tab either as my chassis has just been painted with special paint.

However you provoked me into thinking about a solution.

Brake union stud

Take an M6 set screw, chop off the head and make a stud. Turn down the end of the stud to M3. Rivnut an M6 into the chassis rail. Drill thru the rivnut to the bottom rail at M3. Screw the stud into the rivnut untill it protrudes and becomes tight. Rivit the other side with a hammer.

Comments please?

avagolen - 12/10/12 at 06:11 PM

This is what I have done. Not IVA'd yet, but I hope it will be OK.

I made a tabwasher that interlocks with the chassis and has a raised tab with a hole
in for the locking wire to be wrapped to.

The hole in the washer is large enough to sit 'around' the head of the rivnut so it all sits flush.

Rear_Brake_t_locking

HTH

Len.

theprisioner - 12/10/12 at 08:24 PM

I guess if I was an IVA man and had any experiance with rivnuts I would suggest they can be pulled out. Have you ever buggerd one? They are realy easy to get out all you have to do is punch one into the frame. I usually grind a bit off the head first to minimise the damage to the tube. Alternatively they can come loose and unwind themselves from the bolt. With that clever plate under the union I guess the rivnut could still unwind due to vibration. I dfon't know what the answer is but I am watching this thread like a starving hawk.

avagolen - 12/10/12 at 08:46 PM

Hi all,

Just to try and stop the movement of the rivnuts, I use a permanent threadlock.

Yes I have drilled them out, but only in ally so far.

matt_gsxr - 12/10/12 at 08:56 PM

My experience is as Adi, rivnut not a problem.
Maybe contact the station where you are going to have yours tested in advance, they are very helpful in real life.

theprisioner - 16/10/12 at 04:00 PM

Sylva

Sylva demo brakes

Chester

Chester Sports car brakes

Bluemoon - 16/10/12 at 04:02 PM

quote:
Originally posted by theprisioner
Sylva

Sylva demo brakes

Chester

Chester Sports car brakes

Nice solution, but what a load of rubbish, surely if that works then you reliant on the rivets, they don't go all the way through... Can't remember how production cars fix there T's quite sure the is no locking mechanism, just a bolt?

[Edited on 16/10/12 by Bluemoon]

loggyboy - 16/10/12 at 04:16 PM

Theres no acctuall stipulation about it penetrating. the wording is simply -
2.
A hydraulic and vacuum component must be of adequate strength so as not to be likely to fail prematurely.

3.
A hydraulic and vacuum component must be made of a material sufficiently durable so that it is unlikely to fail prematurely.

4.
A hydraulic and vacuum component mounting/bracket must be secure to the vehicle structure or other components

5.
A hydraulic and vacuum component mounting/bracket must be of adequate strength so as not to be likely to fail prematurely.

6.
A hydraulic and vacuum component mounting/bracket securing method must be of adequate strength and unlikely to fail prematurely.

So as rivets are generally considered adequate for securing brake lines, theres no reason a Rivnut should not be considered adequate, the method of fixing is identical, even in the unlikely event of of the rivnut becoming loose, as long as the bolt is securely in the rivnut, it couldnt spin as bolt would be holding it in place. (As long as it came loose 'after' it was made tight!)

However its all down to opinion, so its just down to what the inspectors oen opinion of 'adequate' is. As mentioned above, a quick call to your choosen centre should resolve it.

[Edited on 16-10-12 by loggyboy]

stevegough - 19/10/12 at 06:32 AM

Sorry, whatever you 'read somewhere' is misinformed / incorrect or you simply remembered it wrong. My 2 tees are simply bolted into rivnuts, and mine was IVAd early last year. (Some inventive ideas in this thread, all the same!).

Bottom line is ALWAYS - read the relevant parts of the IVA manual.

mcerd1 - 19/10/12 at 07:36 AM

quote:
Originally posted by theprisioner

Sylva demo brakes

that's pretty much what I was going to sugggest (although maybe only 2 rivets) that or a bit of angle rivited to the side of the tube (i.e. the T would be offset from the ctr of the chassis rail)

you could even add a blob of PU between the braket and the chassis to be extra safe - if its good enough to hold the floor on alot of these cars then 1 brake union should be no problem

I don't like the idea of drilling right through the rail either, but for a small hole it should be ok depending on how the tube is loaded (even better if its got a welded in sleve to stop the tube getting chrushed)

loggyboy - 19/10/12 at 08:26 AM

quote:
Originally posted by stevegough
Sorry, whatever you 'read somewhere' is misinformed / incorrect or you simply remembered it wrong. My 2 tees are simply bolted into rivnuts, and mine was IVAd early last year. (Some inventive ideas in this thread, all the same!).

Bottom line is ALWAYS - read the relevant parts of the IVA manual.

Whilst that is good advice, on the reading part. Sadly every examiners opinion will difer slightly, its all down to interpretation. No where does it state that Rivnuts are acceptable, nor does it say that they are not! lol

ashg - 19/10/12 at 09:59 AM

mine had t's bolted on using riv nuts for iva. they failed it and made me bolt right through. luckily it was on one of my 19mm braces rather than a main chassis tube.