Have to replace a faulty brake light switch. Not done one before. Have ordered up the Harley version I have seen mentioned in other posts on the HAMB. Am I right in understanding that if someone keeps pressure on the pedal I can replace it without having to bleed the brakes? Looks like the last time this was done thread tape was used. Presuming I do the same?
Just make sure when you pull the old one you have the new one right beside you and ready to go back in, do it quickly.... ....
It's a tapered pipe thread, so thread sealer might be useful...or the part might come with some already applied? or someone will mention that the tapered threads on brake parts are self sealing.
Agree with previous answers, assuming the switch location is below the master cylinder. If not then air will enter the system. How much will depend on how fast you complete the changeover. If just a little then you can bleed at at the switch.
Everyone above is spot on. I just did this a couple of weeks ago. Switched it quickly, used just a couple of wraps of Teflon tape, switch is about even with the master cylinder. No problems. The Harley-Davidson part number you'll want is 72023-51E. It is physically smaller than most on the market, but it works, which is also different than most on the market.
Yep, I tossed a HD switch in the glove box along with a pigtail I made to adapt it to my roadster's harness. The one I started with failed with only a few miles on the car. @Kim Strobeck "donated" one out of his Model A stash so we could make an event the next day, that was years ago, and it is still working so why replace it? It is old, rusty, and works perfectly! No need to hold the pedal, just have the new switch ready to install with some thread sealant on it. Wham, bam, thank you ma'am.
I had a NOS Chevrolet in-line, brake light switch from the late-1930's in my '37 Chevy coupe for over 30- years. I had installed it when I converted to DOT5 brake fluid. Both switch & brakes were still working fine when I sold the coupe. Same switch, same brake fluid and I drove it 2k to 3k miles every year.
As I don't use this type, I prefer electric switch on pedal, I have a question. Does this switch need to ground? If so does using Teflon interfere with that ground? Thanks, just curious..... ...
You don't want someone's foot on the pedal unless you like gettng brake fluid in your eyes. you do not want pressure on the system when you change it. As others said, it is best if when you unscrew the old one you have the new one in the other hand to screw back in.
No ground the way you are thinking, the switch simply interrupts a signal, open or closed. We use them to switch the ground lead. Brake light switch/bulbs have power but no ground, press the pedal and pressure in the line closes the switch, ground complete, lights on. Pretty foolproof...as long as the switch doesn't fail. Millions of cars and bikes use this style switch.
I had about 3 hydraulic ones go bad on our 57 . Added a relay to take the load off the switch, never had one go again.
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