Can someone tell me what it is please

hi all, have bought an s type but havnt got a manual yet. can you tell me what this part is and where it should bolt to.

hi, is a switch for the automatic gearbox ,
for signal and jump at superior speed.

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hi gerard, can this be by-passed. till i find a replacement.

Why not, try to shunt this and control at the car run iwith all speeds goes well…

I think you might find it’s the switch that disengages the ‘hold’ solenoid in the rear brake circuit. When you apply the brakes the rear circuit has a solenoid that hold pressure on the rear calipers until you depress the accelerator. They normally fail after time. You can check by looking under the cabin about half way along the there should be a cylinder in the brake line, try ohmming the wires at the switch to the solenoid to double check,

does anyone know what you have to do to over ride that system.

Looks to me like the throttle switch (auto trans)…should be connected to the throttle mechanism on the carbs

Hi Robert, what year is your car? Paul.

My feeling is that given its location by the throttle linkage its this switch;

Unfortunately my SPC does not have a photo and both my ‘S’s have had that removed a long time ago.

No its not a C20367 solonoid switch…(see photo)…its more likely the throttle switch i mentioned in the post above and shown in the diagram above…Steve…here is a solonoid switch C20367s-l400

hi paul. its a nov 1965

as far as i have investigated it is the anti creep valve for when you touch the brake in drive it activates the cylindrical shaped thingy in the brake line and when you press on the accelerater it releases the brakes and away you go. the reason i need to find out is the car has been in a garage for about 3 yrs and i was thinking the brakes were seized on but the bracket that holds the anti creep valve is not attatched and the plunger on the end of valve is seized in the out position. i need to bypass this valve at the moment to rule out it being the brakes.

yes robin part no c15270

This is a throttle position switch that was fitted to MK2’s/S-Type’s that were equipped with Borg Warner DG250 Automatic Transmissions. It completes a circuit when the ignition is switched on and the throttle is off (i.e.not depressed). The completed circuit activates the brake solenoid located along the inside of the right frame rail and retains brake pressure to the rear brakes while the circuit is completed. When adjusted properly, the circuit is broken the moment the throttle is depressed (when the plunger is allowed out of the barrel) OR when sufficient pressure is detected by the pressure switch located at the rear right hand side of the transmission (It’s a redundant system with two ways to break the circuit).

Because the plunger in your switch is stuck in the open (out) position, your circuit should be open and the brake solenoid should be inactive. To verify that your brake solenoid is not frozen/stuck in the hold position and retaining pressure, you may temporarily crack and re-tighten the brake line fitting that exits the brake solenoid or either one of the rear brake caliper bleeder screws and this will relieve any pressure that has been retained. This shouldn’t be an issue as the solenoid should have released brake pressure as soon as the ignition was switched off the last time that the car was driven.

In terms of attachment, the bracket should be affixed to a stud located on the intake manifold which may be found on the vertical surface of the manifold between the two carburetors. There should be a stamped arm clamped to the throttle shaft which rotates down when the throttle is depressed. This arm needs to be aligned beneath the switch plunger and the up/down position of the switch relative to the arm adjusted such that it opens and closes per the specifications in the manual.

When adjusted properly, the brake solenoid will be activated when one comes to a stop (throttle off - the throttle position switch circuit is completed) and idling (the transmission fluid pressure is low enough that the transmission pressure switch completes its circuit).

The brake solenoid will retain pressure to the rear brakes until:

  1. The throttle is lightly depressed thus opening the throttle position switch
  2. Sufficient transmission fluid pressure is sensed by the transmission switch

Bottom line…with the ignition switched off, the car placed in neutral (on a flat surface) and the handbrake released, you should be able to push the car forward or rearward as the anti-creep system will be inactive as there is no power being delivered to the solenoid.

Hope this helps and good luck with your project.


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Never said it was that switch, I have said from my first answer that it was to do with the solenoid in the rear brake line.

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Hi Robin…my apologies…i thought you were pointing to the solonoid switch in the parts list…looking closer i see its the ring binder loop…Steve

:joy::sweat_smile::rofl::smiley_cat:…+ 20

I ran my Mk2 without the creep facility. I guess it was a curious addition on early automatics - deleted later on as people got used to resting their foot in the brake. Paul.

had your Mrs drive it did you ? :rofl:

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Yes… I was in another car. :face_with_raised_eyebrow: