Lucas Hydraulic Switch

Talk about the E-Type Series 1

Topic author
Northwestern
Posts: 44
Joined: Tue Jun 03, 2008 7:15 pm
Location: Co. Fermanagh
Ireland

#1 Lucas Hydraulic Switch

Post by Northwestern » Fri May 04, 2018 8:28 pm

This is a strange one, can anyone help me please? I've purchased 4 switches so far to replace the faulty one in my S1 4.2 Roadster and none fit. The diameter of the replacements are all too large.
The switch fitted in the car looks exactly like the Lucas C16062 but is stamped on the nut face '37 / 15'.
I've purchased the SNG Barrett upgraded switch C16062U (won't fit); SNG Barrett Lucas copy C16062* (won't fit); Jaguar/Land Rover genuine part C16062 (won't fit); and finally Lucas SMB423 stamped '40 /17' (won't fit). This is incredibly frustrating. The car was restored by Hutson's and all work on it carried out by them. They have supplied 3 of the above switches but none fit. Can anyone help identify the Lucas switch marked '37 / 15' in the car or suggest a correct smaller diameter one to fit? All I can confirm is the diameter of the threaded part is smaller than all the above.
Paul
S1 4.2 Roadster
S1 3.8 Low Drag Coupe

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

Heuer
Administrator
Posts: 12077
Joined: Sat Mar 01, 2008 5:29 pm
Location: Nottinghamshire
Great Britain

#2 Re: Lucas Hydraulic Switch

Post by Heuer » Fri May 04, 2018 8:35 pm

Do what the rest of us do, use a mechanical switch in parallel with the mechanical one. Details in the upgrade Forum.
David Jones
S1 OTS OSB; S1 FHC ODB

Add your E-Type to our World Map: viewtopic.php?f=1&t=1810

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

abowie
Posts: 2002
Joined: Wed Sep 07, 2011 9:15 pm
Location: Australia
Contact:
Australia

#3 Re: Lucas Hydraulic Switch

Post by abowie » Sat May 05, 2018 12:47 am

Assuming that you're talking about the brake light switch, the thread is 3/8" 24tpi. Which is very close to M10 1.5, close enough in fact that I have successfully used metric switches meant for Volkswagen Beetles.
Andrew.
881824, 1E21538. 889457..oops
http://www.projectetype.com/index.php/the-blog.html
Adelaide, Australia

Link:
BBcode:
HTML:
Hide post links
Show post links


Topic author
Northwestern
Posts: 44
Joined: Tue Jun 03, 2008 7:15 pm
Location: Co. Fermanagh
Ireland

#4 Re: Lucas Hydraulic Switch

Post by Northwestern » Sat May 05, 2018 9:26 am

Thank you Andrew. Yes, it is the rear brake light switch. The measurements you quote are exactly the same as the new switches I have purchased, but are all too large in diameter to fit the four way brass brake union in my car.
I'll have to take the switch off today to find out what the diameter actually is.
I'm wondering if Jaguar used different unions taking different diameter switches during S1 production? My S1 is a late production car - maybe with an S2 fitting? Is there a difference?
I had a brain storm and realised the markings on the switch that is fitted in the car is probably of no help as the '37 / 15' is most likely a date of manufacture 37th week of 2015. However, the style of the switch and stamping is exactly the same as the Lucas switches I have already purchased that have too large a diameter of tread to fit.
Any help in nailing down what the switch size is is appreciated.
Paul
S1 4.2 Roadster
S1 3.8 Low Drag Coupe

Link:
BBcode:
HTML:
Hide post links
Show post links


cactusman
Posts: 1649
Joined: Wed Nov 14, 2012 11:09 pm
Location: Hertfordshire
Great Britain

#5 Re: Lucas Hydraulic Switch

Post by cactusman » Sat May 05, 2018 9:50 am

I have fitted several crap intermotor switches and the so far excellent SNGB upgrade without issue. Just a thought but is the four way union the correct one. The thread should be 3/8 inch 24tip. If it isn't there is your issue....
Julian the E-type man
1962 FHC
1966 MGB....fab little car too

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

mgcjag
Moderator
Posts: 3739
Joined: Fri Jul 09, 2010 6:15 pm
Location: Ludlow Shropshire
Great Britain

#6 Re: Lucas Hydraulic Switch

Post by mgcjag » Sun May 06, 2018 8:30 am

Hi All...I had access to one on the new SNG hydraulic switches this morning...im currently making up brake lines on another project.......the thread on the switch i have is definatly not 3/8unf tp24...unfortunatly i cant measure the thread as it is covered in thread seal......the first 3 threads are exposed and an m10x1 fits on there but dont want to tighten up on the thread seal just in case i cross thread.........m10x1 is not an uncommon thread for Jaguar and my current thinking is that although the brake fittings on the E are 3/8 24 the one in the brass connector for the switch is not......i will take this up with SNG on tuesday to get an answer on what the switch thread actually is..
Paul....haveing said this i think that during restoration an incorrect 4 way connector has possibly been used....
.Steve
Will come back with an answer asap
Steve
1969 S2 2+2 & Building a C type replica

Link:
BBcode:
HTML:
Hide post links
Show post links


christopher storey
Posts: 4285
Joined: Sun Mar 09, 2008 3:07 pm
Location: cheshire , england
Great Britain

#7 Re: Lucas Hydraulic Switch

Post by christopher storey » Sun May 06, 2018 8:48 am

Sorry, Steve , but M10 of any pitch was never used by Jaguar to my knowledge in the period we are talking about . Your switch is almost certainly 3/8 by 24 tpi ( 24 tpi is so near to 1mm pitch - .9448 - that it is hard to distinguish between them without a gauge ) .Similarly, the major diameter of M10 is 10mm= 0.3937 inches which is very hard to tell from 0.375 . Going back to the original problem, it seems certain to me that his 3 or 4 way union is too small - I do wonder whether there is an adapter on his old switch which he has not noticed ?
Last edited by christopher storey on Sun May 06, 2018 8:54 am, edited 1 time in total.

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

abowie
Posts: 2002
Joined: Wed Sep 07, 2011 9:15 pm
Location: Australia
Contact:
Australia

#8 Re: Lucas Hydraulic Switch

Post by abowie » Sun May 06, 2018 9:02 am

christopher storey wrote:
Sun May 06, 2018 8:48 am
Sorry, Steve , but M10 of any pitch was never used by Jaguar to my knowledge
M10 1.5 (25tpi) is very close to 3/8" 24. Enough that you can use the Volksie switches without leaks.

Cheers.
Andrew.
881824, 1E21538. 889457..oops
http://www.projectetype.com/index.php/the-blog.html
Adelaide, Australia

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

Heuer
Administrator
Posts: 12077
Joined: Sat Mar 01, 2008 5:29 pm
Location: Nottinghamshire
Great Britain

#9 Re: Lucas Hydraulic Switch

Post by Heuer » Sun May 06, 2018 9:43 am

Be warned that if you are going to use the VW switch you must get one from an official VW source. The replica ones are just as bad as the E-Type version. Anyway I thought SNGB had solved this problem with their new switch? Julian spent a lot of time researching the construction and reasons for failure (contacts arcing as they used ordinary plated metal whereas it should have been brass/copper/gold) and, as far as I am aware they are excellent and reliable. Just make sure you get the one with the re thread.
Image
Direct link: https://www.sngbarratt.com/uk/#!/Englis ... 4beb9c38a3

Part number is C16062U (the “U” is the important bit!) and they are available now from the SNGB web site
David Jones
S1 OTS OSB; S1 FHC ODB

Add your E-Type to our World Map: viewtopic.php?f=1&t=1810

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

mgcjag
Moderator
Posts: 3739
Joined: Fri Jul 09, 2010 6:15 pm
Location: Ludlow Shropshire
Great Britain

#10 Re: Lucas Hydraulic Switch

Post by mgcjag » Sun May 06, 2018 10:00 am

Hi Christopher.....im currently working on some early XJ S3 calipers 1979...yes quite a bit later but i thought it was strange that the hydraulic thread as quoted to me by Automec is m10x1.....i already tried a 3/8 24 and it was the wrong size...the m10x1 fits perfect....will be interesting to hear what SNG confirm the thread as on the switch..Steve
Steve
1969 S2 2+2 & Building a C type replica

Link:
BBcode:
HTML:
Hide post links
Show post links


christopher storey
Posts: 4285
Joined: Sun Mar 09, 2008 3:07 pm
Location: cheshire , england
Great Britain

#11 Re: Lucas Hydraulic Switch

Post by christopher storey » Sun May 06, 2018 1:34 pm

Steve : interesting isn't it ? I wonder when the switch from imperial took place . BLMC certainly started to use metric sizes for brake pipes at some stage, but when this was I don't know

Incidentally, I have just used one of the new improved SNGB switches and it worked straight out of the box

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

mgcjag
Moderator
Posts: 3739
Joined: Fri Jul 09, 2010 6:15 pm
Location: Ludlow Shropshire
Great Britain

#12 Re: Lucas Hydraulic Switch

Post by mgcjag » Tue May 08, 2018 11:24 am

Hi All......So been in contact with SNG....very helpefull......the thread on the new uprated brake switch is the same as the old switch and it is 1/8 NPT(tapered).......the original 4 way unions are 3/8 unf 24 with one port for the switch being 1/8 NPT..... The new style 4 way have all ports as 3/8 unf 24 so the new uprated switch will not fit.......

There is an adaptor available part no BQ247 from Brakequip and others that have a female 1/8NPT to male 3/8-24unf that you could possibly use to fit the new switch into the new 4 way..but i havent tried it......
SNG will look into possibly puting the thread info in the web page and also look at adaptors they could recomend.. All the best..... Steve
Steve
1969 S2 2+2 & Building a C type replica

Link:
BBcode:
HTML:
Hide post links
Show post links


Topic author
Northwestern
Posts: 44
Joined: Tue Jun 03, 2008 7:15 pm
Location: Co. Fermanagh
Ireland

#13 Re: Lucas Hydraulic Switch

Post by Northwestern » Sun May 20, 2018 1:38 am

Dear Steve, thank you and apologies for late reply. I too have been in contact with SNGB and discovered all the switches I have obtained with the Jaguar part number as listed in the parts book won't fit - metric thread. SNGB explained my car must be the 1 in 10 that won't accept their standard replacement! Instead they sent me hydraulic brake light switch - Lucas Part No. SPB401 - and it fits perfectly. This switch is also used in Aston Martin's and Sunbeam.
With the help of my good friend Ed Shaw we fitted a relay, as suggested by David, shown on another page, and after bleeding the system all is fine.
Thanks for advice, suggestions and for learning not to trust the first thing that comes out of the box.
Regards Paul
S1 4.2 Roadster
S1 3.8 Low Drag Coupe

Link:
BBcode:
HTML:
Hide post links
Show post links

Post Reply Previous topicNext topic