brake pedal comes up too high

[banjerman]

I gotta admit I'm stumped on such an unusual problem. I noticed my brake lights were on the other day while it was parked. Reached in an pulled the brake pedal up and naturally the lights went out. What's strange is, the pedal is now about 2 to 3" higher in the up position than it used to be. Much higher than the clutch pedal. It actually felt like the pedal arm was hitting something and keeping it from coming to it's up position. The only thing I've done recently is replace the master cylinder a couple months ago. I even had to put a helper spring on the pedal arm to make sure it comes up far enough to actuate the brake light switch. Any ideas? Am I missing something obvious? Hope someone has an idea. thanks.

 

[IOPort51]

all I can say is the brake light switch is a _PITA!! you may have bent the tab that contacts the switch or even broken it and it has not fallen off yet. I did that a long time ago and re welded it, that was interesting. This may be because of the additional spring ?? I have replaced the switch with a hydraulic switch near the master cylinder. Check the switch tab and let us know what you find.

 

[BajaEdition]

an 85 is a bit out of my expertise, but the early units, 71 and older the master cylinder push rod can be an issue. I wonder if the length of it needs to be adjusted for the new MC. Did you compare any differences in the lengths and clearances?

 

[banjerman]

It sure is a PITA. I took out the driver seat so that I could get a good look at things. The brake pedal arm itself contacts the switch, but wasn't coming up far enough to push it in. But lifting the pedal brought it in proper contact. The extra spring I attached is not real strong, just enough to take the little bit of play out to bring the pedal up the last inch. There is not a tab there. Strange stuff eh?

 

[banjerman]

an 85 is a bit out of my expertise, but the early units, 71 and older the master cylinder push rod can be an issue. I wonder if the length of it needs to be adjusted for the new MC. Did you compare any differences in the lengths and clearances?

Good thought on the MC rod. I was thinking the same thing, but it looked the same as the one I took out, and of course I brought the core back to the place I bought it. So I cant compare now. Being that the brake light switch is stationary, and the pedal arm still pushes the switch in, I don't think the rod length is the problem. I should get myself back under the dash and see if adjusting the switch closer to the pedal arm will contact sooner and the little bit of play caused by the main spring not being strong enough does the trick. Damn if I could even find a parts blow up of that assembly! I've got three different manuals, and not one shows this. The more I think about this, if the switch will move closer, I could take the helper spring off and would take care of it. I'll keep you guys posted. Thanks for the responses.

 

[IOPort51]

I am hoping you are done with this and it was a pleasant experience. But I doubt it.
the switch adjustment is to screw it in toward the peddle, that would be downward.
I mention the up and down reference not to be sarcastic but to mention that if you spend enough time with your head up under the dash it gets a little confused.
The switch and the adjustment show up in the factory service manual but they don't mention that you need another joint in your arm midway between your wrist and elbow and a neck that swivels like Linda Blair to actually service it. Oh and taking the dash off does not help even a little.

this is my new hydraulic switch. I am really proud of it, When I discovered that I was going to have to replace the switch again, three times in 32 years isn't bad I guess, I decided it was time to fix it.
So far I think the brake switch, exhaust donut gasket and the 10 inch wiper blades are the only things they screwed up.

 

[Jroch]

I had this problem on mine with the pedal not rising all the way and catching on the rod, what I did that corrected it for me was blead the brakes out, I found a ton of air in the brake system, this brought the pedal up to the top and greatly decreased the amount I had to push it in during braking, I had to adjust the switch as I didn't have any lights after this

 

[banjerman]

I am hoping you are done with this and it was a pleasant experience. But I doubt it.
the switch adjustment is to screw it in toward the peddle, that would be downward.
I mention the up and down reference not to be sarcastic but to mention that if you spend enough time with your head up under the dash it gets a little confused.
The switch and the adjustment show up in the factory service manual but they don't mention that you need another joint in your arm midway between your wrist and elbow and a neck that swivels like Linda Blair to actually service it. Oh and taking the dash off does not help even a little.

this is my new hydraulic switch. I am really proud of it, When I discovered that I was going to have to replace the switch again, three times in 32 years isn't bad I guess, I decided it was time to fix it.
So far I think the brake switch, exhaust donut gasket and the 10 inch wiper blades are the only things they screwed up.

Hey that's pretty cool !!! I agree, it's a drag getting all twisted up under there. But I did take another look and see the tab that actuates the switch. Cant really move it, and I believe I figured the whole thing out now. The pedal arm was just nicking the cover that conceals the wire harness that is under the steering column. So it wouldn't always let the pedal come back to normal position easily. I managed to coax the pedal over about 1/8" and seems to ok now. I had the steering column loose recently after replacing the wire harness and turn signal switch. So I must not have put things back together like it originally was. It's the little things isn't it?

 

[banjerman]

I had this problem on mine with the pedal not rising all the way and catching on the rod, what I did that corrected it for me was blead the brakes out, I found a ton of air in the brake system, this brought the pedal up to the top and greatly decreased the amount I had to push it in during braking, I had to adjust the switch as I didn't have any lights after this

Another good tidbit!! I also just happened to have redone the rear axle upgrade and complete brake job. I bet rebleeding the brakes is in order, as I've got too much free pedal as compared to what it used to be. Next weekend for sure. Thanks for everyone's help. You're great!!