54 brake lights?

bull_islander

What's the culprit?  The brake lights only light up when I've got the pedal fully pressed.  It has power brakes, so the only time they'll light up is when I'm at a full stop (only time I get that much pressure on the pedal).  How/where do I adjust?

Geoff

If you have a hydraulic switch, it has gone bad.  If a mechanical switch, it needs the linkage adjusting.

onerare39

Bull,

The pressure switch is attached at the banjo fitting.  It is not uncommon for these to go out.  You can replace the switch without needing to bleed the brakes.  You can perform a simple test of your brake lights by pulling the wires off of the switch terminals and putting a jumper wire between the two wires, a paper clip will work.

Hope this helps.

John

bull_islander

Thanks.  

John, that's one nice looking engine compartment!

onerare39

Thanks. That photo was in 2009 when I got it back on the road after the engine rebuild and paint.  I drive it regularly and try to keep everything clean and tidy.

John

RichardD

Also be aware that a 'low pressure' switch is available. NPT. 
https://www.ronfrancis.com/prodinfo.asp?number=SW-32

jjbubaboy

Hey,
Here is another great alternative if you have repeated brake switch failures.
Friend of mine put one in and has had no problems.


http://www.ecihotrodbrakes.com/inline_brake_light_switch.html

Jeff

50C8DAN

Just a quick note.  If you are using DOT5 brake fluid you will need to make sure you are using a pressure switch that is resistant to this type of fluid.  They are available from Ron Francis (as noted above) and Harley Davidson dealers.  There may also be other sources out there.  I know as I use DOT5 and this was a problem when I first switched over.

Frankvintagefullflowcom

At first I thought this to be not likely true, thinking that there must be some other factor in the equation that was causing the failures, but in my limited knowledge of rubber compounds, I've surmised that the only reason a brake light switch would suffer from the use of DOT 5 is if the diaphragm was made of silicone rubber. Silicone fluid is basically inert and shouldn't cause a problem with rubber components, but it will soften (or worse) silicone rubber parts and is considered incompatible in hydraulic systems.

I always change to mechanicals anyway but it's something to think about.....if you were needing something.

Frank

Frankvintagefullflowcom

JJ,

You got a gift of one day between storms! Get that T-Plane out and stretch its legs!

F

jjbubaboy

Hey F,
That would have been great!! The 'honey do' list seemed to be more urgent...

bull_islander

Alright, replacing the switch worked for several weeks.  
Then I had one brake light stop working.  Not the bulb, as the signal lights worked and it illuminated with the headlights.  So I replaced the switch again.  They worked again for another several weeks.  And then the same brake light stopped working again.  Replaced the switch again to still only have one brake light this last time.  
These are Borg Warner switches that are coming from the local O'Reilly's.  Why would only one light be failing?  I haven't changed fluid since acquiring the car last fall, so that could be likely if it's something in relation to the fluid and the makeup of the BW switch as Dan suggested above.

RichardD

Crazy things happen with old car electrics!!
I.E.: yesterday I had to install an #1156 bulb under the hood so the flasher on my hazard lite system would work ! This to increase the resistive load, BUT after they had worked for a year ??? Craziness
Have you jumpered from the battery to the load side of the switch to see what happens?  Suggest going to the generic lever switch on the brake pedal arm. Would eliminate the pressure switch problems. Has for me and others.

Park_W

Am I missing something?  If either stoplight works, then the stoplight switch is OK and the problem's elsewhere.

RichardD

You are correct, Park. I should have read the last comment! 
The post was for months about an intermittent switch with both lites not working. Now it seems to be down stream. Lucas wiring or bulbs? lol~~

bull_islander

Thanks Ken.  I'll look there.  It seemed odd that the switch fixed the problem twice though temporarily (the first time was strictly a pressure issue; not sure why a new switch fixed it when it was only one non-working brake light the second time, but I went with it).
It does seem to have to be wiring related to the brakes.  As mentioned all other functions of the tail light work (turn signal and illumination with head lights).

duncan

What body style of 54 Hudson do you have  Ray

Glowplug

Diagnosis from afar is at best craps!  In another area there is a common denominator that is seldom blamed, but many times the culprit.  The wire connection  block under the dash. If the plug ends or the connections in the block have expanded... faulty connections will occur.