Author Topic: brake lines thread size  (Read 433 times)

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Offline buzzer

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brake lines thread size
« on: Wednesday,September 07, 2022, 03:53:55 AM »
I have to replace my brake light switch and struggling to find what the thread size is to make sure I get the right replacement. It connects to a union block near the engine. Any idea what the thread  is.

Dave
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Offline 4129R

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Re: brake lines thread size
« Reply #1 on: Wednesday,September 07, 2022, 04:27:22 AM »
It connects to a standard 3 way brass brake pipe union, so it is the same thread as the brake pipe male union.

I think that is 5/16" UNF.

Offline buzzer

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Re: brake lines thread size
« Reply #2 on: Wednesday,September 07, 2022, 04:50:05 AM »
Yes its the same thread on that union and thanks.

Dave
Dave,

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Offline dakazman

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Re: brake lines thread size
« Reply #3 on: Wednesday,September 07, 2022, 03:40:58 PM »
  Here is a list of other s2 fittings
http://www.lotus-europa.com/manuals/misc/brakes/S2_Order2.html

Dakazman

Offline jbcollier

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Re: brake lines thread size
« Reply #4 on: Wednesday,September 07, 2022, 04:06:01 PM »
The thread is 3/8NF.

Offline dakazman

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Re: brake lines thread size
« Reply #5 on: Thursday,September 08, 2022, 05:11:55 AM »
The thread is 3/8NF.
   
   JB,
Are the S1 and TC’s the same thread size? I know there are differences in the system layout.

   Dakazman

Offline 4129R

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Re: brake lines thread size
« Reply #6 on: Thursday,September 08, 2022, 05:28:17 AM »
I have just tested the 3 way brass union off a TCS and it is definitely 3/8" UNF, the same as all the brake pipe unions on a TCS.

Offline jbcollier

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Re: brake lines thread size
« Reply #7 on: Thursday,September 08, 2022, 07:08:14 AM »
Sorry D-man, can’t answer that question definitely.  The most common brake fittings are 3/8NF until the switch to metric.

Online BDA

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Re: brake lines thread size
« Reply #8 on: Thursday,September 08, 2022, 07:17:58 AM »
I would be surprised if the S1 and TC brake fittings have different threads. Metric stuff didn’t creep into Brit cars till much later.

Offline jbcollier

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Re: brake lines thread size
« Reply #9 on: Thursday,September 08, 2022, 07:19:37 AM »
Never expect the expected when dealing with a Lotus!

;-)

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Re: brake lines thread size
« Reply #10 on: Thursday,September 08, 2022, 07:20:59 AM »
 ;D

Offline 4129R

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Re: brake lines thread size
« Reply #11 on: Thursday,September 08, 2022, 08:42:18 AM »
I would be surprised if the S1 and TC brake fittings have different threads. Metric stuff didn’t creep into Brit cars till much later.

Except for the Renault gearbox.

My latest car is 4688R and that does not differ in bolt types.

Offline dakazman

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Re: brake lines thread size
« Reply #12 on: Thursday,September 08, 2022, 09:46:33 AM »
  That sums that up🥱😂
Dakazman

Offline buzzer

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Re: brake lines thread size
« Reply #13 on: Friday,September 09, 2022, 03:43:36 AM »
Ik so 3/8 unf.  cheers guys
Dave,

Other cars. Westfield SEiW. BMW E90 Alpina D3. BMW 325 E30 convertible and Range Rover CSK

Offline buzzer

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Re: brake lines thread size
« Reply #14 on: Friday,September 09, 2022, 04:46:37 AM »
Found the original part number lucas 34619B. also used on Norton Motorbikes. so managed to pick one up on Ebay
Dave,

Other cars. Westfield SEiW. BMW E90 Alpina D3. BMW 325 E30 convertible and Range Rover CSK