TheSamba.com :: View topic

Fri Oct 14, 2016 9:01 am

I'm currently working on getting a 1971 standard beetle back to stock / working configuration. Both of my brake light switches on the master cylinder have tested out as bad (and thus no brake lights), and so am getting ready to replace them.

The Bentley shop manual mentions retaining / reusing "sealing washers" when replacing the brake light switches, but the new switches I ordered did not come with sealing washers, nor do I see any mention of anything like these on any of the VW parts websites. The threads on the new switches look like they might be tapered / pipe thread type arrangement (??).

So does anybody know if new brake light switches require "sealing washers" of any sort? Or if not, how are the switch's threaded connection sealed to the master cylinder body? Should teflon tape or pipe compound be used on the switch's tapered threads to help prevent leaks (like used in plumbing connections)?

Fri Oct 14, 2016 9:15 am

That's an error in the Bentley manual. Perhaps the person who wrote that section was thinking of the
residual pressure valves, which do use sealing washers.

Just like the other tapered-thread joints in VW's, the warning light switches normally do not require
any thread tape or other sealant.

Fri Oct 14, 2016 9:16 am

I'm pretty sure that they do take a copper washer. The old washer is most likely stuck to the master cylinder or the old sender.

Does the sender screw all the way in without binding? Then it's not pipe thread.

Pipe tape would keep the threads clean for easy removal.

Fri Oct 14, 2016 9:58 am

The pressure switches do NOT take a washer. Now, that funky master cylinder used in 68-69 with the extra piston inside for the warning light switch, that switch did use a washer, but the pressure switches were always taper fit.

I've never used anything on the threads for the pressure switches, just make sure it's all clean.

Fri Oct 14, 2016 10:03 am

and dont use the china switches Ive blown out 5 or more of them and when they blow you have zero brakes!! the only place Ive got good switches were from.....hear it comes.....autozone. I tried the vw venders thay all sem to have crap. the auto zone ones have been in for over 5 years now with no leeks or issues and great breaks.

Fri Oct 14, 2016 10:37 am

Depends if you bought a 5 dollar switch from a VW vendor - those are crap. The 15-20+ dollar ones are the better ones... usually. There was this report a few months back about one of those more expensive switches dying as well. http://www.thesamba.com/vw/forum/viewtopic.php?t=655747&

Fri Oct 14, 2016 11:01 am

Ok, thanks guys -- that's helpful! I'll look for any washers present when I remove the old switches, but suspect that Bentley manual is inaccurate on this and really don't need them. The threads on the new switches definitely look to be tapered pipe-thread types.

I bought new switches from WW that are supposed to be the "German" ones, but have also heard it's a bit a crap shoot regardless nowadays. We'll just have to wait and see how long these ones last I suppose...

Fri Oct 14, 2016 1:19 pm

"German" is mostly meaningless marketing jive. There are parts called "German" that are chinese crap sold by a company
with an office in Germany. Many of the best-quality VW parts makers do not make them in Germany.

Sat Oct 15, 2016 7:02 am

I dug through my pile of parts and the switches stand off from the master cylinder body by about 1/4 and inch,too much room for a washer. I removed one and indeed they are pipe thread. The check ball fittings look like they have washers but they needed heat to remove so I stopped there.