Brake lights are slow to come on

Jerome, unfortunately I don't have a spare wheel cylinder handy. I have one over at my parents but it'd be a little while before I get back over that way. The issue has been around for a long time, but I'm not sure when it started. I did switch master cylinders when I did the disc upgrade, but I'm not sure if it started immediately after the switchover. Just something I noticed one day.

Turbo Mike, they come on immediately when activated, just have to step on the pedal hard to activate them.

Randy, I'll jack up one side when I get home from work today and have Kelly hit the pedal and see how firm the front and rear wheels are stopped. I was reading a little more and read that some people use a 2lb residual valve on the rear drums when using front discs. Maybe this would keep the extra pressure I need???

That does sound like a possibility there as well. All the buses and think the ghias to use a regulator when using a disk/drum combo.

If I do find that the rear wheels still spin some, and the rears aren't getting enough fluid pressure, could I test this before spending money on a residual valve? Perhaps by plugging the rear brake line port on the master, and thus eliminating that circuit altogether (just as a test). Anyone know what size bolt I would need to plug that port. I think I read the lines are M10x1.0, but not sure on that and definitely don't want to strip anything.

Couldnt you just adjust the rear brakes tight for the test?

That would be easiest, but I'm worried the results may be skewed. Since the star adjusters only really push out the bottoms of the brake shoes, the tops where the wheel cylinders are may still have room to expand. Maybe I'm overthinking it though???

Very little if any.....either way it will be a lot less than just regularly adjusted and much easier then taking the lines loose and having to re-bleed them and all of that

fluxcap wrote:That would be easiest, but I'm worried the results may be skewed. Since the star adjusters only really push out the bottoms of the brake shoes, the tops where the wheel cylinders are may still have room to expand. Maybe I'm overthinking it though???

You're overthinking it. Just adjust them all the way out and test. I had the same problem you describe with the Jolly Rancher just before Bulli. Replacing the rear switch and adjusting the rear brakes fixed it.

I'll try that first then, but they're pretty tight already. I adjusted them before starting this whole ordeal, and they have a pretty good drag to them.

I've been having the same problem for the longest, and on both my 72 and 74 super's. i've tried everything as well, bleeding for countless hours, adjusting the front and rear shoes till they were dragging, still the same. i even tried replacing all the rubber brake hoses thinking they might be expanding or something, but still the same. like jerome said, its prolly either the ports are too small, or maybe it just takes too much pressure to activate the switches, idk. It seems to be a popular problem on thesamba as well. I was also thinking about just hooking up some sort of electronic switch like modern cars. maybe even fabbing some kind of bracket to hold a ford, or jeep brakelight switch, since they are easy to mount. but otherwise, i've gotten into the habit of stopping way before i need to so the person behind me sees the brakes, and then letting off, and drift to a stop. gets kinda annoying tho, especially when the tard behind you is 12 inches away from your rear bumper

i wonder if this is a problem when you have disc brakes on the front and rear? (less room to expand perhaps?). i noticed its not as bad on my 72. maybe cause i have discs up front? not sure. it would be interesting to see if the front switch is activating before the rear one.

Bugman114 wrote:it would be interesting to see if the front switch is activating before the rear one

When I tested each one with the test light, there no noticeable difference between front or rear as far as how much pressure I was putting on the pedal. Both seemed about the same. I just ordered a Hella switch from here:
http://www.rallylights.com/detail.aspx?ID=2105
Still going to try a few more tests tonight or tomorrow, but if they fail to do the trick, maybe the Hella switch will work better. Still going to put the electric switch in on Friday (unless I miraculously fix it before then!!!).

After that, I'll probably wait until I have a full weekend with nothing to do (school is almost over!) and pull the master cylinder and look into the items Jerome mentioned. The electric swith will do the trick for a while, but man I've already got a rats nest of wiring, and I'd really just like to get the dang thing working as it should.

Well, last Friday I went ahead and mounted a micro switch to the pedal cluster. It's out of view and my brake lights now come on instantly. I made a small bracket for the switch that is held in place by the rear pedal cluster bolt. It works great and I'm really just glad to have brake lights, even if not the solution I was wanting. I also still have one of the pressure switches wired up as well, so if the micro switch dies, I'll still have my delayed brake lights.

Later that same evening the Hella pressure switch came in the mail. I just installed it this evening and me and Kelly bled the brakes again. I disconnected the pedal switch, and tested the Hella switch. No-Go. Just like all the others.

I did also adjust the rear brake shoes all the way out like Glenn had suggested over the weekend to see if that would help. I think it did get them to come on just a tad bit sooner, but still way after the fronts had locked up.

I think it must just be something weird with the master cylinder itself. Probably just buy another one someday and then tear this one apart to see if I can find anything wrong with it.

Oh well, I've got brake lights one way or the other, so I'm happy!

post some pics of your bracket, and set-up. I really want to do this as well.

I'll try and get a few pics this evening. It's very basic. Just a piece of sheet metal bent into an L shape. The cherry switch has two holes in it, but they are way to tiny to get any kind of bolt through, so it's actually held in place by two smaller cotter pins. I'm proud of how well it works, not so proud of how it looks. But it's pretty well hidden!

Bugman114 wrote:post some pics of your bracket, and set-up. I really want to do this as well.

Here's the crude set-up. It's nothing more than a piece of sheet metal bent into an L. The end of the L that attaches to the pedal cluster bolt has a slot cut in it so it slides behind the cluster bolt and is held tight when you tighten the cluster bolt. The switch then just sits on top of the other end. I put a thin piece of rubber between the switch and bracket to keep the unused terminal from shorting out. The other terminals are soldered and then covered in shrink tubing. I wired the switch to function as "normally closed". The pedal (when not pushed) is keeping pressure on the switch and keeping the circuit open. As soon as you push the brake pedal, the switch is released and the circuit closes, letting the juice flow.

The switch has two very small holes in it, and I had no bolts/nuts that small, so I found a couple of cotter pins that fit perfectly. Drilled corresponding holes in the bracket and connected it all together with the pins. No slop at all, the switch/bracket are very firm. The bracket is black and I needed to draw some lines on it to know where to cut it, so I put blue painters tape on, so I could see my lines. I never took the blue tape back off (yes, I AM that damn lazy) so that's the blue you see in the pics. The switch is hidden behind the gas pedal so I'm not worried about its ugliness!

Only thing to make sure of, is that your bracket is small enough and placed so that it doesn't get bumped by the gas pedal.