Although I converted to a dual master cylinder, I plumbed a line for a hydraulic brake switch. I tried using a mechanical switch but had difficulty engaging the brake pedal to operate the switch. I purchased a new ACDelco switch as the reputation of old was of quality.

After installation, I noticed a puddle of fluid under the truck. I determined the leak was brake fluid under the position of the switch. All the hydraulic lines where fine. I finally determined the leak was coming from the plastic portion of the housing where the contact pins go. I did some research and found that others were having the same problem.

ACDelco has let me down. For some, this can be a big safety issue. I thought I would pass this along if you are in need of a new hydraulic brake switch.

 

I'm battling a leaky switch myself. Mine is from the threads (I think).

 

I'm on my third switch now and still leaking... other than mechanical are there other options ???

 

I've had more trouble with them getting less sensitive with age, than with leaks.
Really aggravating to have to bleed the whole system just to replace that one little item....
I put a mechanical switch for an aux. LED panel on the Aurora, simple and positive.

 

 

I replaced my unreliable hyd. switch with a motorcycle / atv switch. My brakes are not stock so it was easy to adapt a bracket off the pedal assembly, might work with a stock setup as well?

 

Sufficient hydraulic brake pressure is another issue. Painless sells a low-pressure switch for $18 (80174), a bit pricey. I do not know an alternative to a brake pedal operated mechanical switch but believe there may be other options. The concept is quite simple but the solution is dumbfounding.

I ordered a new switch. If the problem continues, I’ll have to go back to the drawing board.

 

I used a Ron Francis low pressure hydraulic switch and so far no leaks. It is also supposed to be compatible with DOT 5 silicone fluid.
Mark

 

I bolted one of these to the bottom of the floor (road side) and bent the arm 90° to touch the pedal arm. This switch is always 'On' (closed) and is adjusted so it only goes 'Off' (open) when it is in contact with the pedal. Standard Motor Part SLS40, $8.57 @ RockAuto.

 

I plan on using a Ford cruise control pressure switch.


It will have to be used with a relay as it opens when there is pressure and is supposed to activate with 5-10 lbs of pressure.

 

Research Hobbs pressure switches. Some models are adjustable, with the option of NC or NO.Here is an example found on
Amazon. It is NO (normally open) I have used these with good results. Honeywell HOBBS 76575-4

B

 

I just replaced my pressure switch with an adjustable mechanical switch from ron francis. My pressure switch had gotten a short in it that caused the tail lights to be on all the time. Then it slowly lost sensitivity until it didnt work at all. With the mechanical switch, now the brake lights turn on as soon as I touch the pedal, and the tail lights do not go on by themselves.

 

like I said 3rd switch and its still leaking....so I decided to go e-lectrically. Bought two switches., one like CBeav shows above and a Keep-it-Clean version... Both work identically... and opposite of what I thought they should. They are spring loaded and in the 'resting position the switch is open... the brake lights are off.. As you move the lever the switch makes contact and the lights come on. To me that meant the switch had to be in front of the brake pedal so it could pull the lever. I mounted the switch to a 90 degree bracket and then screwed that bracket to the brake pedal framework under the dash.

Then for a couple of hours I tried 13,450 different combinations of springs, chains, wire, rods, brackets, combined with lots of expletives and a sore neck from laying under the dash. My Problem was that I couldn't get the switch to "on" itself where I wanted it too. Finally the brake circuit gods dropped a wrench on my head and I came up with the idea of using a turn buckle. WA- LAAA!!!. Infinitely adjustable, stable and strong. Now to 'unplumb' the hydraulic leaker, bend another tube to add an inch to the line and bleed again... oh, and reroute the switch wiring from under the cab to under the dash...

thought some of my hydraulically challenged brake switch buddies might like to see this fix. or at least laugh at my feeble attempts.

john

 

Look's like you got it John, good idea using a turn buckle to dial in the switch.... problem solved!

 

My 95 had a recall to replace if leaking and I believe all pick ups with them had to have a jumper harness put inline with it that contained a fuse. Supposedly they could cause a fire without the fuse?