Register now to get rid of these ads!

Technical BRAKE LIGHTS STAY ON AFTER PEDAL PUSHED

Discussion in 'The Hokey Ass Message Board' started by Sactownog, Apr 4, 2018.

  1. Sactownog
    Joined: Jan 19, 2018
    Posts: 248

    Sactownog
    Member
    from SAN DIEGO

    I am trying to figure out why my brake lights stay on after I push the brakes. I can go and push the pedal a few times and they will turn off. it is a new brake light pressure switch and when I changed it I did not bleed brakes again "which I will do soon" but I am wondering if this is a pressure issue or a faulty brake light switch issue or a pedal sticking issue.

    the whole board has been helpful with my questions to get this car going right. thank you for your time.
     
  2. I would say it is your pressure switch hanging up.
    Vic
     
    Gammz likes this.
  3. alchemy
    Joined: Sep 27, 2002
    Posts: 20,405

    alchemy
    Member

    Do you have a return spring on the pedal to bring it back to the fully upright position?
     
  4. zeke1270
    Joined: Aug 23, 2011
    Posts: 187

    zeke1270
    Member
    from Alberta

    Return spring for me also.
     
    olscrounger likes this.

  5. Sheep Dip
    Joined: Dec 29, 2010
    Posts: 1,572

    Sheep Dip
    Member
    from Central Ca

    Like alchemy says.....if you pull up your pedal by hand do the lights go out? Could be spring or adjustment.
     
    Model A Vette likes this.
  6. Latigo
    Joined: Mar 24, 2014
    Posts: 739

    Latigo
    Member

    That switch is usually pressure (hydraulic) operated. If the brakes need to be bled, sure, bleed them first. There may also be some crud in the line that is blocking the fluid releasing pressure from the switch. Pull it off and check. Look inside the master cylinder with a flashlight. At the bottom there are small holes that relieve pressure when the peddle is released. They may be plugged. Was this problem the reason for changing the switch? If it worked correctly before it could be a bad switch.
     
  7. Atwater Mike
    Joined: May 31, 2002
    Posts: 11,625

    Atwater Mike
    Member

    I got surprised after hearing of a 'common problem' with pressure switches. My NAPA parts man said there was a memo about bad brake pressure switches from various sources.
    A whole 'run' of them.
     
  8. plym_46
    Joined: Sep 8, 2005
    Posts: 4,018

    plym_46
    Member
    from central NY

    Usually indicates pressure build up not allowing fluid to return to the mc. Perhaps old rubber flex lines deteriorating, Tue will allow fluid under pressure to flow but restrict return. Might be debris block in the return poet in thee mc. Could be a faulty new switch. This Chinese and Mexican made stuff they let in these days is always a craps shoot. Ant brake drag when the light sticks??? Give some thought to using a universal mechanicals switch.
     
  9. Boneyard51
    Joined: Dec 10, 2017
    Posts: 6,440

    Boneyard51
    Member

    Two things could cause your problem, bad switch or residual pressure when you take your foot off the brake. Bad switch.. replace. Pressure problem, there have been several suggestions already posted, I might add flushing the hydraulic system, which is just bleeding the system a lot. Doesn’t take much residual pressure to keep the light on. Bones
     
  10. I got a bad one from Napa myself. Just about anything I've gotten from Napa for my Ford has shit the bed on me.
     
  11. captain scarlet
    Joined: Jun 11, 2008
    Posts: 2,429

    captain scarlet
    Member
    from Detroit

    I brought an expensive pressure switch from Bob Drake. I was told that was a bad idea, so I double wired for a mechanical switch but didn’t install it. The pressure switch lasted 2 months. I fitted a mechanical one. Been fine ever since.


    Sent from my iPhone using H.A.M.B.
     
  12. Sheep Dip
    Joined: Dec 29, 2010
    Posts: 1,572

    Sheep Dip
    Member
    from Central Ca

    The pressure switch that came on my Wilwood proportioning valve on my 40 coupe lasted about 2 months before it went south. The Auto Zone replacement is still working.
     
  13. I've had a lot of trouble with the pressure switches on my Ford. I can't count how many I've replaced. I don't think the quality is very high, and I buy good ?? switches. It could be a bad switch.

    I also was working on a Dodge last summer that the brake lights would stay on. The owner had replaced the master cylinder and was unaware that the push rod might need adjusting to give him some free play so the master could release its pressure. Built up pressure was holding the brake light switch on.
     
  14. mike bowling
    Joined: Jan 1, 2013
    Posts: 3,560

    mike bowling
    Member

  15. Mr48chev
    Joined: Dec 28, 2007
    Posts: 33,861

    Mr48chev
    ALLIANCE MEMBER

    Another vote for return spring. If the brake lights are on and you can reach in and pull the pedal back and they go out that is your problem.
    I put a Ford pressure brake light switch on my 48 Chev when I put the dual master cylinder in and replaced it about every two years after that. they don't tend to last too long and if they are down under the car next to a frame mounted master cylinder that time is cut shorter. I'll go back to a stock switch on the rebuild.
     
  16. Ralphies54
    Joined: Dec 18, 2009
    Posts: 772

    Ralphies54
    Member

    Is there a power booster? They have been known to not allow the M/C to return! Ralphie
     
  17. A Boner
    Joined: Dec 25, 2004
    Posts: 7,419

    A Boner
    Member

    Too much electricity getting to the taillight bulbs.
     
    bobss396 and captain scarlet like this.
  18. Sheep Dip
    Joined: Dec 29, 2010
    Posts: 1,572

    Sheep Dip
    Member
    from Central Ca

    That is correct, it also has to be adjusted properly.
     
  19. I got one with my PV too, that leaked from day 1. Onto the Napa unit that took too much pedal pressure to trip. I got one on eBay, I should get another. It was around $12 and takes 45 PSI to actuate.
     
  20. Simple fix, wire in a dimmer switch... or vise grip pliers on the wire.
     
  21. dan c
    Joined: Jan 30, 2012
    Posts: 2,520

    dan c
    ALLIANCE MEMBER

    ford used 'em for a long time, but i'm not crazy about pressure brake switches. a leak waiting to happen.
     
  22. Boneyard51
    Joined: Dec 10, 2017
    Posts: 6,440

    Boneyard51
    Member

    They re also slower than a mechanical switch, could make a difference. Bones
     
  23. Bandit Billy
    Joined: Sep 16, 2014
    Posts: 12,286

    Bandit Billy
    ALLIANCE MEMBER

    Put the beer down that step away from the shrink wrap!
     
    bobss396 likes this.
  24. I ran pressure switches in lots of cars and once in a while an old one would fail. I have had only 2 fail on me in recent years and both were brand new. Hecho en China... The one I have now acts quickly and comes on as soon as I move the pedal, well before the stopping power comes in.
     

Share This Page

Register now to get rid of these ads!

Archive

Copyright © 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.