Brake lines. Please help

[rzrz]

Replacing the original brake lines with Goodridge braided ones the thread of the new brake lines seems incompatible with the one of the brass (?) "nut" at the end of the copper brake pipes. The threads won't engage (left side rear) or, if they engage (right side rear), too much force is needed to turn the brass nut around. The brass nut fits easily on the original brake lines.
On the other hand the locknut supplied by Goodridge fits easily on the male end of the original brake lines, so the threads should be (almost) the same.
My car is a 1991 S3C. Specs of the Goodridge brake lines as described in the useful links (TVR S3 brake pipe specifications), confirmed (before buying) by Goodridge in the Netherlands.
I don't understand what's wrong.
Please help

Gr, Raoul

[Barkychoc]

If it is at the diff end of the trailing arm pipes the fittings on some cars have imperial fittings here - my guess is you have a metric flexible pipe with imperial fittings.
The way to sort it is either replace the rigid brake pipes or get exchange imperial flexible pipes.

I fitted a goodridge set to a V8S last year - despite a number of conversations with goodridge it was very very painful.

[phillpot]

Yep, definately sounds like a mix of metric and imperial threads.... all together now "it is a TVR"

The thread pitches and diameters are very similar.

A metric nut will screw onto an imperial male thread (but probably strip if tightened)

An imperial nut will not screw onto a male metric thread

HTH.

[Matt]

If it helps the part number for the brake hoses (for the V8s which I believe is the same as the S3c) is TTV0912-8p.

There are 4 hoses in the set (of 8) which are similar in length, but as Chris stated the inboard rear hoses have imperial threads at one end. I ended up labeling them as everytime I put them down I'd have to recheck which was which...

regards

Matt
V8s

[Deadfast]

Barkychoc said:

I fitted a goodridge set to a V8S last year - despite a number of conversations with goodridge it was very very painful.

And we still don't know yet whether the custom made hoses will fit until it comes off SORN! If anyone wants details of the hoses let me know.

[Spathodus77]

If you take the old hose and try to fit the 'teeth' of the thread inside the 'teeth' of the new thread will they fit side or not? If they don't fit inside then it is definitely a mismatch in thread. If they fit inside and are a good, snug fit then your component should fit OK to the car. Try holding a couple of bolts with the same thread together to see what a good fit is like.

To clarify hold the threads parallel to each other with the hose of one of the components trailing off to your left and the hose of the other component trailing off to the right for this test.

Not sure I'm explaining too well...

Ralph

[phillpot]

Matt said:

If it helps the part number for the brake hoses (for the V8s which I believe is the same as the S3c) is TTV0912-8p.

Isn't S3c drum brake rear so only six hoses in set ?

S4 may be same as V8 (eight hoses) ?

Spathodus77 said:

If you take the old hose and try to fit the 'teeth' of the thread inside the 'teeth' of the new thread will they fit or not?

Look very carefully, they are very similar !

[Spathodus77]

I did try the test with some metric and imperial brake fittings that I have lying around before responding. The test does work with these. If they are the same type they fit like a glove...there is a definite mismatch over seven or so spirals if the threads are different.

Ralph

[mep12345]

I fitted a set last year all couplings on the car were metric except for the inner rear ones that were imperial - I changed these to fit the goodridge hoses and make the car imperial all round, do it with care and it is really easy, then you also know where you are (i.e. metric rather than a mix and match)

Also be careful as the metric hoses can appear to fit but they will not be leaktight when done up

[phillpot]

Spathodus77 said:

...there is a definite mismatch over seven or so spirals if the threads are different.Ralph

I totally agree, but not too easy to see if you're trying to do it under the car with second hand fittings, poor light, dirty hands and brake fluid running down your sleeve

3/8 unf = 24 tpi

10mm fine = 25.1 tpi

[rzrz]

Thanks a lot, really helpful!
Searched the internet: there are adapters. If I could find one which can connect M10x1 with 3/8 UNF that would solve the problem. Anyone familiar with these?
Next weekend I'll check all the other connections to see how big the problem really is.

Gr, Raoul

[The Big G]

I have just received a set from goodridge and as far as I can make out there is a mixture of sizing for my V8s which I have listed below:

• All the front flexis are M10.
• Rear trailing arm to caliper flexis are M10.
• But the flexi pipe to the trailing arm from the chassis is 3/8 UNF on both ends.

• The flexi pipe to caliper should be fitted with a copper crimp washer between the two.

This is what I have been supplied with and of course yours may vary.
Of course, at some earlier point in the cars life any of the flexi pipes may have been changed, and as such the female connector fitted to the copper pipe may no longer be what may be expected.

[Fireblade69]

They weren't seriously still using imperial in 1991 were they? 1881 maybe, surely not 1991.

[Top Gear TVR]

whitworth was an engineer, europe just did some rounding with a calculator..........or fag packet

i know which i would have preferred

[Barkychoc]

The metric Goodridge hoses I saw had a little 'nick' in the middle of the union corners (quite often seen on metric but not always) where the imperial ones did not.

An example nut is below look at the corners



Acknowlegement to minispares.com for the picture

[rzrz]

Update:
2 front hoses: metric both ends
rear hose: imperial both ends
Contacted Goodrige Benelux. Just went there, luckily only 30 km from my house, and got 4 imperial ends fitted for 14 Euro.
Should fit now.

Gr, Raoul

[Oldred_V8S]

Barkychoc

As the brake line expert , do you know what fittings are used at the master cylinder?

Many thanks.

Paul

[The Big G]

I am in the process of trying to sort mine out at the moment too. The rear connectors seem to be m10, the front ones are larger and I would guesss at m12. Just need to order some now to find out for sure. I presume m12 is also the size required for the bias valve.

Anyone have an idea what to use as a banking plug for the rear unused space. I think mine has previously use a m10 bleed nipple but its so badly borrowed I can't tell.

[phillpot]

Everything M10 on my S3 (master cyl. bias valve etc), no M12 anywhere.

A bleed valve is usual way to blank the spare outlet.

[mep12345]

IIRC mine were M10 front and M12 rear and I used an M12 bleed nipple to blank the spare.

see here

ETA just looked at my photos and my website is wrong M12 front, M10 rear and M10 bleed nipple

Edited by mep12345 on Monday 23 January 20:51