Stop Right There

A little while ago at a car show I was told that my brake lights didn’t work. I was concerned for obvious reasons. The cars behind me can’t see me slowing or stopping, and the fact I’m running LED’s was a concern. It’s not as if I had a blown bulb or something which would be an easy fix. The guy told me that while we were in a long queue to get into the show he “didn’t see my lights come on at all”.

After he left explaining it to me my fellow Mustang mate David heard what he said and suggested I pressed the pedal so he could take a look. I pressed the pedal as I normally do when braking and the thumbs up and a “yep fine”, no problems there then. We swapped places and he pressed the pedal, no problems again as the lights came on as expected. This is now turning into a puzzling scenario. Perhaps an intermittent switch fault, or is it the fact I am very light on my brakes? I don’t pull away with a boot full of revs and I don’t jump on the brakes to stop me either. In traffic I pull away gently by just letting the idle move me forward, when I brake it’s just a light pressure enough to stop. Less wear and tear on the engine, less fuel used, it will help avoid a boil over and the big positive is there will be less brake dust on my chrome wheels to clean as well.

I made a trip to Mustang Maniac to be in the company of fellow petrol heads and I explained what had happened to Adam. He suggested a swap over of the switch for the power assisted disc version. When I asked what the difference was he told me the spring for the switch was not as strong and the wires were on the other side of the switch bracket. This translated means that the normal drum brakes need more pressure to apply the brakes with a longer pedal travel. That switch is stronger as the brakes don’t actually apply until a reasonable force is used. The power assisted disc brakes need less pressure before the brakes apply, so the switch needs to be activated a little earlier. Simple when you think about it. So with advice from Adam of course I was going to replace it.

Here the two are side by side. Old drum brakes on the left (still working when tested with multi meter) and the new one for powered discs on the right. It’s also the same switch for a 67-68 as well.

I got to work where the switch is attached to the pedal via, which is in turn mounted around the master cylinder lever, which is also attached to the pedal via the same pin. The switch and the lever are held in place by a fairly strong retaining pin which needs to be removed.

Depending on the state of the pin it could be rusted and a little penetrating oil may help with the removal. I used a long pair of angled pliers to pull it out, be careful you don’t slip and take a chunk out of your steering column.

With the pin removed the connecting bar to the brake master will be able to be pulled off the pedal to the side.

Move the brake lever halfway off the pin. This will release the closed part of the switch casing, a hole which the pin fits through in order to stop the switch from coming off the pedal itself.  The switch itself can now be pulled down as the opposite side of the switch is open at the top of the casing to allow the switch to be removed. This saves having to completely remove the brake lever bar if you didn’t want to. While I was at it I decided to regrease the pin and plastic bushings. When removing the pin take care to retain the plastic bushing inside the lever bar. There are also a nylon washers on either side of the pin which don’t need to be removed, but you can if you want to. Below is the pedal push rod to the master cylinder being removed.

I sprayed the pedal pin with some white grease ready for reassembly later and also the inside of the push rod and bushings. If they haven’t been replaced for a while, replace them just for the sake of it  as they are very cheap replacement parts. That would also eliminate and play in the pedal, if you have any that is.

Side by side with the closed side of the switches compared. The powered disc brake version on the right with the terminals on the closed side of the switch. The left has the terminals on the open side.

The other side of the switch where you can see the open side as it were. Notice the terminals on the left manual switch are now facing up.

Once the removal has been completed now it’s a simple the reverse to fit it. Apply grease to the pedal pin that locates the push rod bar and the bushings. I used plenty and can always wipe it up after. If you go mad with the grease you could drop or run grease onto your footwell carpet, be careful or lay some old rags around, just in case.

Place the switch up to the push rod bar which will sit between the open and closed sides of the switch. Align the holes and slip it back over the brake pedal pin. You may need to slightly rotate the switch so that the open end is located all the way up to the pin. The switch itself should sit square at the end of the brake push rod, in line at the end of the lever bar as shown here. If the switch is not located square, the lights could be on all the time or not come on at all.

The push rod lever bar has straight edges deliberately, this means when the pedal is depressed the lever bar moves on the pin’s axis and the edges press the top of the switch down to make the contact.

Check the motion of the pedal and you should here a very faint click as the switch engages. The retaining sprung pin can be located into the hole in the pedal pin. This retaining spring is quite a tough to open around the pedal pin in order to be properly located. Here just the retaining pin tip is located in the brake pedal retaining hole.

You may need the pliers on the spring a little to get it passed the pedal pin and snap it into place.

A little more spray on white grease and pump the pedal to make sure full and correct operation.

Lastly you just need to swap the connecting block to the other side of the switch. It’s possible that you may need to free up a little more cable but you should have enough slack in the loom to allow you to do this. Here the switch is fully assembled with the connector in place with the red and white wires showing, before I re-wrapped them again. The connecting block can only fit on in one direction as the male terminals are set at angles.

From a slightly different angle.

Again, check the FULL motion of the pedal and make sure everything is clear from snagging. You should now be able to check that your brake lights are now working correctly. Lastly you can either clean up the grease on the visible parts or leave it as is. I left mine for a couple of trips in order to let it all work around, then I cleaned it up, but not to much as you need the lubrication there.

The noticeable difference being that the pedal moves less now before the brake lights come on which suits my style of driving. Also even if I just cover the brakes it should give the car behind earlier warning that I am actually slowing down and avoid being rear ended.

In total it took around just over half an hour plus taking the pictures to complete. It took a further few hours for my back to recover after laying upside down in a Mustang footwell and twisting into positions that any circus contortionist would be proud off. The cost of the project was £16.80 from Mustang Maniac, click here for the link for the switch I used. A small price to pay to be safe.

Quite what the issue was with the brakes not working or just the switch playing up i don’t know. Replacing the switch is simple and like I just said, it’s better to be safe than sorry. Quite what my next project will be I’m not sure, but I will find something no doubt, hopefully without having to book an appointment with a chiropractor! 🙂

About One man and his Mustang

I'm just a man with a Classic 1966 Ford Mustang Coupe and a collection of tools that just keeps getting bigger in order that I could do the job right. When I first started this blog this is what I wrote: "I had bought a project car, that had been neglected, set fire to, rusted and abused. As a result of that she needed a bare metal strip down, a nut and bolt restoration." Four and a half years later the car was completed, on the road and shown at the UK's premier Classic Car Show, everything that was done to that car is documented here. I now have the privilege to drive one of America's most recognised cars and a true Icon, the Ford Mustang. I'm still sane after the blood, sweat and tears, so would I do it again? Oh yes!
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4 Responses to Stop Right There

  1. steve fraser says:

    Had the same issue with my 67. Mine has a servo and had been changed to discs on the front so the original switch was far too strong. Fitted the same one as you and it works fine.

    Liked by 1 person

  2. David Frost says:

    Had to replace mine earlier this year, ordered from Mustang Maniac on Tuesday pm and it was delivered Thursday morning,can’t complain at that,was about £24 delivered from memory.

    Liked by 1 person

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