Beware Roadster Parts - Brake Safety Switch - Tubing Nut Thread Size Trap

[zKars]

Dear Datsun Brethren

I try from time to time to come to the aid of all manner and nature of Datsun people, and last weekend I had the good (cough cough) fortune to work on a 69 Datsun Roadster.

It had leaking brake lines after replacement, and I was able to assist the owner with the repair. Something about "just tighten the nut more. It won't break"...

But along the way, I discovered something that we need to be aware of as righteous Z owners. Chances are it will never happen to you, or me, but you need to know.

As part of the trouble shooting, the owner of said Roadster brought a spare "Switch - Brake", you know, that safety brake light switch block on the fender well that turns on your dash BRAKE light if either side of the brakes loses pressure. We have discussed it's care and feeding previously.

Here it is on a Z in case you visual learners need a picture.

Here is the one he brought with him from his Roadster. I was questioning whether perhaps his ancient beast used DIN flares or some craziness and that might the source of his leakage, so he brought an example for me to examine.

Looks da same to me as our Z part, right?  We use the same one a 510 and I'm sure many other models, right?  WRONG!!!!

The tube nut threads on this abomination are some SAE nonsense, yikes 3/8-24!!  Yes the horror of it all. SAE parts on a Datsun. As if having SAE seat belt bolts isn't enough of a embarrassment for most Datsun owners already.

Now this comes as no surprise to any Roadster owner I'm sure, as they preach that the front half is SAE and the back half is Metric. Talk about fake news!

Anyway, some day, some kind hearted Roadster-owning soul may offer us unexpecting trusting Z owners his spare "Switch-Brake" when we are at our most vulnerable, stuck on the side of the road (in Podunk Kansas of course), and yee shall be sorely disappointed and down hearted should you attempt to install it. Ensure he attempts to thread in both M10x1.0mm nut and a 3/8-24 before bothering to send it.

It is true what is written...    46100-26001 is not the same as 46100-U5200

(maybe the insides are the same, doubt it though!)

You've been warned, my job is done here. Go forth and merrily forget this nugget of truth. 

 

 

[Mike]

Good to know, thanks for posting this info!  I have been looking for one of these for my '71.  They are hard to come by (in good shape anyway).  I've been pondering the purchase of another one so I can restore it.  This will give me the information that I need to make a purchase.

[zKars]

17 minutes ago, Mike said:

Good to know, thanks for posting this info!  I have been looking for one of these for my '71.  They are hard to come by (in good shape anyway).  I've been pondering the purchase of another one so I can restore it.  This will give me the information that I need to make a purchase.

Glad to help. I might have a few spares I could part with... They are easy to open and clean up. 

[zKars]

sorry

Edited September 29, 2020 by zKars

[Dens240]

Curious about the 280Z switch...part number 46100-N4200. Any similar advice around that one?

[zKars]

3 hours ago, Dens240 said:

Curious about the 280Z switch...part number 46100-N4200. Any similar advice around that one?

Not really. By the time 280’s came out, I suspect any other model that might have the same item would have the M10x1.00 threads. But take nothing for granted