Technical Brake switch location

Finishing up the last of the plumbing on my brake lines. Have a pressure switch from Ron Francis. I’m putting it in one of the unused ports on the right side of the master cylinder (have 2 ports on each side for front and rear. 4 ports total).

Question is, is there any difference in the “timing” the front and rear ports “see” pressure?

I should know the answer to this but been drawing blanks all day trying to remember. I want to put the switch in the port that will see that pressure first/fastest. Currently have it stuck in the front brake port as you can see in the pictures but not convinced that’s right.

Thanks in advance.

SPark

 

OOP"s I didn't see the photos when I posted so I deleted the post country Joe is referring to when I said he needed an adapter. I didn't know that piece even existed.

If the fittings are the same I would probably put it in the one going to the front wheels though as they usually receive pressure slightly before the rears. That may be the reason for the low pressure switch though as most everyone ties it into the rear brake line behind a floor mounted master cylinder on the frame rail.

 

Looks like an adapter is in place. I think.

 

Pressure in the brake system is almost the same everywhere, except after a proportioning valve. So it should be fine there.

 

I prefer the GM electrical brake switch.. A lot less headaches...

 

You should have left your original post. I thought it was a valuable piece of information to warn someone else that might be researching the same situation. And as I look back at the last photo, I want to say that hex plug in the rear port might be pipe thread? Hard to tell.

 

There is an adapter between the switch and MC. It is inverted flare and they are available from Speedway.

The front plug is inverted flare and came with the CPP MC. Actually comes with 2 plugs so you can run lines off either side and plug what you don’t use.

Thanks.
SPark

 

To expand on what Jim is saying. Primary camber can not pressurize until secondary chamber becomes pressurized and vice versa. This system self balances it's self once all gaps are removed at all 4 corners of brakes.

 

Cool beans, I didn't know that that adapter existed.
The way most of us had to do it was buy a br*** T with 1/8 pipe threads and then get the fittings that are the reverse of your adapter. Pipe into the block with a female flare fitting to hook the line to.

Your switch is a lot more protected than mine is as far as debri or other stuff hitting it. I had to replace mine about every 18 months but I drove the truck every day and put a lot of miles on it including driving 47 miles one way to work and back for a year. 3 years of that were basically driving on a dirt/mud road or lane for 1.2 miles in all kinds of weather. It got so bad that I kept a spare brake light switch in my ditty box in the truck.

 

I gave up on hydraulic brake light switches over a decade ago.

Mechanical ones are far better, won't leak, and are a snap to replace, in the odd event that they fail.

 

A mechanical switch will also turn current on sooner.

 

Yep use one of the simple mechanical arm switches (1958 Chevy truck, STANDARD MOTOR PRODUCTS SLS43), not a pressure switch. Mine is screwed to the bottom of the angled floorboard and touches the long vertical portion of the pedal arm. You can bend the arm slightly if needed to adjust when the lights come on. And, it will never burn out like 98.7% of the pressure switches do.

 

I always set them to trigger the lights, the instant the pedal is touched, well before actual braking force is applied.

Extra warning time.

 

And the way that you find out that the switch burned out might not be a pretty one.

 

I also use a GM arm type switch [tired of changing stuck pressure switches] but I don't trust it either. To monitor brake lights, I have a red light in the inside header panel that's wired up to the brake light switch. Whenever the brake lights are activated, the red light comes on directly in my line of sight.
I've wired in one of these lights in all my hot rods...gives me peace of mind.

 

I do use a pressure switch and am very aware of the high failure rate. I have a red pinpoint light on the dash to indicate whether or not the switch is working though. I don't want to find out the brake lights don't work the hard way.

 

Noting that the master pictured is a CPP item reminds me that CPP produce an all singing master (proportioning and metering included) which also has a takeoff for the hydraulic switch. Not sure which circuit this is plumbed to. I have one on my '32 coupe project (it's a bit bulky but the all in one aspect attracted me) so I will take a look and see if I can work it out. It's installed and bled so I will only be able to conduct a visual check. Only suggesting this as there presumably was some logic applied to their design.

For those who persevere with a hydraulic switch, changing to a Harley item (swaps straight in but has blades for the electrics) avoids the switch failures.

Chris

 

To add to what Rocky and Center of the Galaxie said about inside light. I had issues with my stock signal switch in the 51 contacts for the Brake lights so I hooked the stock in dash signal lights to the Rear light wires instead of the Fronts. now both dash lights work with Brake lights and tell me they both are working and also work correctly with the signals. Nothing extra to add.

 

I usually true to keep a couple of GM mechanical brake light switches around when I am help people with the wiring, from my prospective. HRP

 

Question?? Do the extra inside brake indicator lights work even if the stop lights don't????

 

Not unless there an "open" in the circuit. Burned out bulbs would cons***ute an open. My indicator light just shows there is current coming out of my brake light switch on application.

 

I used a mid 60's GM switch on my swinging pedal setup. Welded a small tab on the pedal arm for the ****on of the switch to ride against, a small bracket on the steering column holds the switch. Good thing about this style is it is adjustable by turning the locknuts. I first had a pressure switch, half the time it wouldn't turn the lights on until the pedal was halfway down.

 

My new Wilwood MC and adjustable prop valve kit came with a pressure switch installed. I removered it and replaced it with the stock one of my 56 single MC. I barely put any pressure on the pedal and the brakes are on. I check to see if the brake lights are working each time I take the car out.. I'm happy with the older technology with the exemption that a lever on the brake pedal arm was on my 49 Chev pu...who's to say.

 

The way I do it as long as there is power from the switch the dash indicator lights light up. You would not know if a bulb is burned out just stepping on the brakes, However when you trip the signal lever the flasher tells ya you have a bulb out if you can still hear it.

 

Yes, mine do. I often check to see if the actual brake lights at the back of the car are working by stepping on the brakes before I open the garage door, and look for the reflection of the lights on the door.

 

Thanks, my point being; the inside markers don't tell you if the outside(brake lights) are working...

 

This! That's the O.E. brake light switch on my '64 Chevy II. I've used that style on a couple of other cars that didn't come with them, and I think the minor fabrication required to install was well worth it.
I'm in the camp that doesn't trust (and have had to replace several) pressure-activated switches.

 

I’ve used pressure switches for years on old Ford pickups and found if you use an OEM Ford piece or quality aftermarket piece they work well for me. No China **** or off brand stuff allowed. Couldn’t find an OEM Ford piece so went with the Ron Francis unit. Had good luck with them in the past.
SPark

 

Correct, only that the switch is still doing it's job. I don't remember growing up through the 60's 70's and even into the 80's switch failure being so common.