Announcement

Collapse
No announcement yet.

Brake lights come on for no reason

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Jeffry Cassel
    replied
    change switch. If it is still a problem and brakes are adjusted ok consider the turn signal switch . The brake light circuit is routed thru the turn signal switch and lots of weird stuff is caused by a bad turn signal switch.

    Leave a comment:


  • jpepper
    replied
    I think the pushrod on the power booster is adjusted wrong. It is a little too long not allowing the piston in the master to fully retract and open the return port. Heat causes expansion and pressure builds which turns on the light. With the lights on, loosen the master mounting bolts. If the lights go out, it verifies my assumption. Take the master off the booster. You will notice the pushrod has an adjustment screw at the end. There is a specified length in the shop manual. The piston in the master should not compress at all when the master is held flush to the face of the booster. While the master is off check to make sure rust, corrosion, and/or dirt has not built up between the piston and the retaining ring on the master. This too can prevent full return of the piston. Clean it if necessary.

    Leave a comment:


  • karterfred88
    replied
    Originally posted by Warren Webb View Post
    No hill holder or brake fade. The push rod has around 1/8th" movement before contacting the power brake booster.
    When they come on, they go off if you bounce the pedal, just put in a new switch. Or convert to a manual electrical contact switch at the pedal--best way. The quality of the hydraulic switches is so poor now a new one could start doing the same thing, and the pedal switch will never leak either.

    Leave a comment:


  • BILT4ME
    replied
    I used to have this problem on my 59 Lark where the MC is located under the floor. I discovered it was an alignment issue where I had a spacer on the wrong side of the MC and it caused a bind between the rod and the piston inside the MC. Figured out the correct spacer location per the Shop Manual and problem solved.....35 years later! Back when, I could do the "Fonzie jukebox-on move" on the front fender to get the lights to turn off.

    Your is mounted on the firewall, so you may not have the same issue. I would definitely look into a new brake-return spring, lubing the pivot, and maybe a new sender. You may also still have air in the system that is expanding, causing the pressure to increase on a hot day.

    Good luck!

    Leave a comment:


  • Warren Webb
    replied
    No hill holder or brake fade. The push rod has around 1/8th" movement before contacting the power brake booster.

    Leave a comment:


  • stude dude
    replied
    Are you experiencing any brake fade? Do the brakes smell 'hot' after a relatively short drive?

    Chris.

    Leave a comment:


  • SC38DLS
    replied
    Being a fairly new Studebaker owner I don't know the different models well enough to know if you have a hill holder but if so & if it has residue buildup it will keep the light on.

    Leave a comment:


  • Warren Webb
    replied
    The master isn't full to the brim but it may be the return spring. I'm going to lube the pivot with some KROIL & see is that helps. Will let you know.

    Leave a comment:


  • E. Davis
    replied
    Make sure your master cylinder isn't too full and doesn't allow for expansion when the fluid heats up. That's what happened to mine.

    Leave a comment:


  • studegary
    replied
    To me, it sounds like you have insufficent pedal clearance to allow the master cylinder rod to fully retract and have some free play. This is allowing pressure build up in the brake fluid when the ambient temperature rises, causing the brake light switch to activate.

    Leave a comment:


  • StudeRich
    replied
    The MOST likely problem Warren is the Pedal Return Spring on the cross shaft under the dash is weak, this is a very common situation on the Suspended Pedal (Ford) setup.
    Exactly as Post #5 and 6 said.

    It's gotta be Henry's fault! Lol!

    I do not think the Pedal is heavy enough to actuate the Hydraulic Brake Light switch, but it IS possible that it could cause the issue Gary mentioned, pressure build-up from the Bleed hole being covered and the extreme Temp change in the Semi-Desert area. MAYBE!
    Last edited by StudeRich; 04-23-2016, 03:36 PM.

    Leave a comment:


  • thunderations
    replied
    Any fluid other then DOT3 seems to cause premature failure of the pressure switches. I just had one start leaking around the crimp holding the electrical post insulator, but that was with DOT 3 so it was another matter. Had a lifetime warranty, so got another and fixed the problem. Some parts are good to get from local parts stores for that reason, ONLY. I have never had one fail "ON", only off.

    Leave a comment:


  • Skip Lackie
    replied
    I have had the same problem with the brake pressure switch on a LaSalle, which uses a switch similar to Studebaker. I believe they can fail either way: sticking on or sticking off.

    Leave a comment:


  • jclary
    replied
    We've had these discussions before. Brake switch failure. Most of the time, the switches fail to light up. That is...they quit performing their job to turn the lights on. Here, yours is taking the initiative to turn them on when they are not needed.

    Since it is a pressure switch, you would think there is no way for this to happen under normal circumstances. I wonder if it can happen from "thermal expansion?" Let's say you park your vehicle, it cools, and, relative to ambient temperature, the system, maintains barometric pressure normal for the altitude in conjunction with temperature. Then...with the warming of the day, and the temperature increases, there is the possibility that a tiny obstruction in the master cylinder vent that prevents it from allowing air to escape (in other words, equalize) "thermal expansion" occurs building enough pressure to activate the switch. An easy check for this is to wait until the switch turns the lights on, and unscrew the cap. I have seen this before, but not on my vehicles.

    Last year, I posted a thread on the opposite problem. After replacing a couple of switches on one of my cars using silicone (DOT 5) brake fluid, I tore into the switch to investigate. Since we have lost most pics from threads posted before the server switch, I had to find the old thread and restore the pic. Here's the link to that thread.

    http://forum.studebakerdriversclub.c...402#post959402

    Leave a comment:


  • JoeHall
    replied
    Originally posted by rockne10 View Post
    Could also be as simple as a weak pedal return spring.
    Only if it has a mechanical switch. There's no way a bouncing pedal will cause a pressure switch to come on, even the ultra sensitive ones like I installed. If its a mechanical switch, and that is happening, need a stronger spring, and/or adjustment for more pedal travel before it trips the switch.

    Leave a comment:

Working...
X