Correct Brake fittings?

[Grizzly]

Hi all.

Can anyone tell me what the correct brake fittings should be for a S4 Elan?

I am having a bit of an issue, i have the pipes off the car and want to make some new ones but i've just managed to order the wrong fittings, i did a search and i read the fitting should be 3/8-24 but after buying enough to redo the car i've have found there wrong.

So i have compared the old and new fittings and the thread is obviously much finer on the old ones so i've done a bit of searching and found Girling tend to use 3/8-20 fittings (which would make sense) but that doesn't necessarily mean Lotus have used them in there cars?

So can anyone tell me what they should be so i can finish my Shiny brake lines

cheers.

[Bombay Racing Green]

They might be metric. My +2 had one early imperial front caliper and one later metric type. The rear ones, I believe, were always imperial. I hope it helps.

Regards,

Pete

[AHM]

Mine are

3/8 UNF which is 3/8 x 24 standard, common, brake fittings.

The hoses should screw onto a banjo, and then onto the calliper.

Check the fittings with a 3/8 UNF nut and bolt.

[Bud English]

Good info here on fittings, flares, and common mismatches.

http://www.fedhillusa.com/webnuts/common%20flares6.pdf

They are also a great US source for British fittings and Cunifer lines. I've no connection to them except being a satisfied customer.

[Grizzly]

All a little confusing but i think it must have had some brake lines fitted at some point because the flex hoses are 3/8 and the brass junctions are 3/8 but everything else is Metric it would appear, bit odd as the lines look original? thought the 70's where still Imperial so it's a little strange to see a mix of the two?

O well as i have plenty of 3.8 i will just do them all the same size.

Thanks for the help.

[billwill]

Maybe by the time the S4 was being made, it was getting hard to get 3/8 imperial 3-way and 4 or 5 way junctions, so they used metric ones and if they could not get 5-ways, they moved the brake switch from Hydraulic to mechanical at the pedal.

But they perhaps kept 3/8 imperial for the ends so that standard flexible hoses would still fit.

~~~~~

Or instead of Lotus it might be a previous ownere that did that.

[billwill]

All a little confusing but i think it must have had some brake lines fitted at some point because the flex hoses are 3/8 and the brass junctions are 3/8 but everything else is Metric

This sentence does not make a lot of sense, what do you mean by "everything else" ?

There's only the master cylindere (and servo) that are not included by the first part of the sentence.

[69S4]

Maybe by the time the S4 was being made, it was getting hard to get 3/8 imperial 3-way and 4 or 5 way junctions, so they used metric ones and if they could not get 5-ways, they moved the brake switch from Hydraulic to mechanical at the pedal.
.

Mine must have been one of the transition cars then as it has both a hydraulic switch on the 4/5 way and a mechanical switch on the pedal. The pedal switch is the one wired up.

[Grizzly]

All a little confusing but i think it must have had some brake lines fitted at some point because the flex hoses are 3/8 and the brass junctions are 3/8 but everything else is Metric

This sentence does not make a lot of sense, what do you mean by "everything else" ?

There's only the master cylindere (and servo) that are not included by the first part of the sentence.

Sorry i have confused myself i tried screwing the new fittings into some of the old fittings which were wrong, so i panicked a bit

Right i have the steel brake pipes off and on the floor, i have new male and female 3/8-24 fittings, before i make the pipe up i screw the opposite 3/8-24 fitting in to make sure its correct thread, i made up the long front to back pipe which was correct (the new fitting fit fine in the 3 and 4 way union), so i went on to rig up the 3 way to rear flex pipe and found my flex hose wouldn't screw into the new female on the end? so i tried the other end/flex fittings (front fit rears didn't, turns out there metric) there is then the rhs front pipe has a joint in it which also Metric and the chassis to body joint is Metric too.

So i have ordered new Flexes as a matter of course and i'm hoping they come 3/8-24 so i can just make the pipes all 3/8 throughout. I'm assuming the Flex to calipers is correct.

If that makes sense

[RichardHawkins]

Grizzly,

I am on holiday at the moment, so can't check my car, but from memory all the hard brake line fittings were 3/8" UNF. My car is a 1968 S4 Elan, and has a mechanical brake light switch at the brake pedal. I would be surprised if a car of your age had not had the brake lines changed previously. I think you should try to use a consistent system on your brakes, i.e. do not mix metric and imperial.

Richard Hawkins

[Esprit2]

Early calipers used inch fittings (3/8-24), while later calipers switched to metric fittings. It was a Girling change, and it affected all Lotus models. I don't recall the exact date, but I believe it was in the late 1971 into 1972 time frame... faulty memory, I could be wrong on the timing. My Elan parts manual shows one set of calipers and bleed screws for the S1, and another set for the S2 & Coupe. Perhaps that's the change-over point.

The rest of the caliper features were the same, just the port threads and fittings changed. There are screw-in adapter fittings available that will allow metric calipers to be used in inch systems, and vice versa. With the proper adapter fittings, either caliper can be fitted to any model-year Elan.

As time passed and inch inventories were used up, the metric parts became the standard service replacement parts. So it's very likely that any older model that required replacement calipers at some point, may have metric thread calipers in inch thread cars. Either adapters were used, or the plumbing was changed to match the calipers.

Regards,
Tim Engel

[AHM]

Check your banjo fittings also - if the hoses were metric you will need 3/8th ones

Depending of course on the calliper entry. There are 3 different front hoses 1 for early cars perpendicular entry and banjo, 2 for type 14 callipers one for perpendicular entry and banjo and one for straight entry no banjo.

The early calliper is I think a type 12 calliper, and the later a type 14. Both 3/8 UNF.

I believe that all are 3/8 UNF and many parts of the braking system are common to all series. I don't know about the sprint, but I've not seen any of the parts suppliers selling metric fittings.

I've not heard of a Girling changeover to metric. We usually change screw threads when we change allegiances so UNF from the second world war, and Metric when the French and Germans took over! around 1975. I suspect most British manufactures went bust first.