Brake light sensor sticking - (1 Viewer)

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tucker74

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Hey,

The previous owner of my 9/75 FJ40 replaced the brake master w/ a '75 model instead of the '76 one for the front disks. When I took it to my local shop they noticed the front brakes binding - and took out the valve that keeps constant 10psi on the front drums. Well, the brakes work great (and aren't wearing as bad either ;)) - but now the light sensor under the brake pedal doesn't switch off on it's own - you have to pull the pedal up w/ your toe manually. Before the pedal was really stiff and didn't depress much from the top - thus releasing the switch. Now it depresses about half way - but doesn't seem to have enough spring to release the switch. Anyone had this problem - should I replace the switch? adjust? replace the spring?

Tucker
 
Simple adjustment of the switch, or possibly the return spring is missing.
Did the shop remove the master to work on it? If so, they could have missed getting something exactly as it was when putting it all back together. I would make sure the switch is not loose, and that the peddal return spring is there, and works, and go from there.

Good luck!

-Steve
 
They didn't remove the master - just the line and valve and replaced line (LCS performed service - relatively positive done right). Guess I'll have to pull it off and tinker w/ it - switch seems to work ok, couln't adjust anything with it mounted behind the pedal. Could be the spring on the pedal as well - just wondering if any one else had experienced this.

Tucker
 
Switch will have a jam nut that holds it in position. Back this off, should be a 12mm wrench, and turn the switch in, and check if it is working properly.

Not that big of a deal..

You are not alone, done this too a half-dozen trucks over the years...

Good luck!

-Steve
 
Mine does it right now, if its any consolation. :D
And yes I've already fixed it once.
Check for a small rubber pad on the plate that activates the brake switch, if it is missing it can cause the same symptoms. Being the cheap fawker that I am, I just stole one off the clutch pedal and glued it where the brake one should be. Problem solved.
 
Bailey is on the track that I ended up following with my fj60...turned out that the little rubber pad that the brake pedal arm bumps against had worn a depression in the middle. No adjustments (nor pulling up on the pedal with my toe) would reliably make the brake lights turn off. Once I noticed the depression in the middle of the pad, (from nearly 16 years of the brake light switch pushing on the rubber) I ordered a new rubber pad and the problem was solved.
 
The return spring mentioned above is located just under the steering wheel on the right side and it connects to the brake assembly. Mine was not connected when I got my FJ40.
 
Same problem with mine. Took my switch out and took it to the local autoparts store and got a new switch for about $15. Then put a return spring on it and haven't had a problem with it sense.
 

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