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Ron Kwas · May 14th, 2015, 13:07

Mike;

Your experience with the hydraulic pressure sensing Brake Light Switch is quite common. See: http://www.sw-em.com/safety_bulletin_4.htm

In short, it's because of the effects of how slowly the pressure comes up in the Braking System, but if you are interested, you can see a failed switch dissection, and all the gory details in my article here: http://www.sw-em.com/hydraulic%20bra...es%20notes.htm

I recommend (to all owners who still have hydraulic pressure sensing Brake Light Switches in their vintage Volvo, from 444-122 and 1800 models, including RHD) that they check their Brakelight function often, and consider upgrading to a Pedal Position Sensing Switch (PPSS). This brings with it the distinct advantages of Reliable Brake Light function (mechanical switches are reliable. Volvo as well as the entire automotive industry realized their advantages, and changed over to these in the late sixties), plus what I call Early Brake Light function (since contact closes as soon as Brake Pedal is moved from its resting position, way before any hydraulic system pressure is made, this gives more stopping time/distance to the driver following...which might be of particular interest in busy California! I leave it as a mathematical exercise to calculate the additional stopping time/distance at a given speed).

As you can see, I've been on a bit of a mission to get all vintage Volvo owners to make this upgrade to their vehicles for their, and their passenger's additional safety. It's a simple, inexpensive change with major advantages!

Full Disclosure: I have developed and offer retrofit and upgrade kits with which to add PPSS to all models of vintage Volvos. In the most recent effort (which is nearing end of development right now), I developed a kit specifically for the RHD Amazon in collaboration with members of this forum (I will let them out themselves if they so choose). See: http://www.volvoforums.org.uk/showthread.php?t=118895

Kit for RHD Amazon will be available very shortly! Switches for all other models are available now. See: http://www.sw-em.com/swemkits.htm#Br...Light%20Switch

Cheers from Connecticut to California!

May 14th, 2015, 13:07	#3
Ron Kwas Premier Member Last Online: Today 11:51 Join Date: Jul 2007 Location: Connecticut, USA	Mike; Your experience with the hydraulic pressure sensing Brake Light Switch is quite common. See: http://www.sw-em.com/safety_bulletin_4.htm In short, it's because of the effects of how slowly the pressure comes up in the Braking System, but if you are interested, you can see a failed switch dissection, and all the gory details in my article here: http://www.sw-em.com/hydraulic%20bra...es%20notes.htm I recommend (to all owners who still have hydraulic pressure sensing Brake Light Switches in their vintage Volvo, from 444-122 and 1800 models, including RHD) that they check their Brakelight function often, and consider upgrading to a Pedal Position Sensing Switch (PPSS). This brings with it the distinct advantages of Reliable Brake Light function (mechanical switches are reliable. Volvo as well as the entire automotive industry realized their advantages, and changed over to these in the late sixties), plus what I call Early Brake Light function (since contact closes as soon as Brake Pedal is moved from its resting position, way before any hydraulic system pressure is made, this gives more stopping time/distance to the driver following...which might be of particular interest in busy California! I leave it as a mathematical exercise to calculate the additional stopping time/distance at a given speed). As you can see, I've been on a bit of a mission to get all vintage Volvo owners to make this upgrade to their vehicles for their, and their passenger's additional safety. It's a simple, inexpensive change with major advantages! Full Disclosure: I have developed and offer retrofit and upgrade kits with which to add PPSS to all models of vintage Volvos. In the most recent effort (which is nearing end of development right now), I developed a kit specifically for the RHD Amazon in collaboration with members of this forum (I will let them out themselves if they so choose). See: http://www.volvoforums.org.uk/showthread.php?t=118895 Kit for RHD Amazon will be available very shortly! Switches for all other models are available now. See: http://www.sw-em.com/swemkits.htm#Br...Light%20Switch Cheers from Connecticut to California!