Brake pressure differential switch 67-69

Anything Corvair related
Post Reply
erco
Posts: 334
Joined: Wed Apr 29, 2020 8:45 pm

Brake pressure differential switch 67-69

Post by erco »

Does anyone sell just the switch that screws into the junction block? Shown in red in attached images.

brake switch.jpg
brake switch2.jpg

User avatar
azdave
Corvair of the Year
Corvair of the Year
Posts: 1957
Joined: Fri Dec 11, 2009 1:27 pm
Location: Phoenix, AZ

Re: Brake pressure differential switch 67-69

Post by azdave »

Don't think so from any Corvair vendor I know of but that small switch might be a part common to other GM vehicles of the era.
Dave W. from Gilbert, AZ
65 Corsa 140/4
66 Corsa 140/4
66 Corsa 140/4 w/factory A/C
66 Corsa 455 Toro V8
65 Monza Convertible 110/4
66 Monza Convertible 140/4
65 Monza 4DR 140/PG w/factory A/C
65 Monza 4DR EJ20T/5

erco
Posts: 334
Joined: Wed Apr 29, 2020 8:45 pm

Re: Brake pressure differential switch 67-69

Post by erco »

Right again, azdave! Turns out it's a whole assembly with springs, pistons and O-rings. That screw-in part is just a fixed electrical contact. A rebuild kit is just $12, I've emailed this company to confirm it fits Corvairs. I'm surprised Clark's doesn't carry these (assuming they fit).

Info page: https://musclecarresearch.com/gm-pd-valve-kit-4

Rebuild instructions: https://www.musclecarresearch.com/gm-3956727-rebuild

$1 seat puller tool: https://www.musclecarresearch.com/brake-valve-seat-tool
brake diff switch.jpg
brake diff switch.jpg (119.33 KiB) Viewed 248 times

erco
Posts: 334
Joined: Wed Apr 29, 2020 8:45 pm

Re: Brake pressure differential switch 67-69

Post by erco »

Owner Scott replied to use a different one:

That looks like this one:

https://www.musclecarresearch.com/1972- ... ve-autopsy

This is the kit for the valve in my article:

https://www.musclecarresearch.com/gm-pd-valve-kit-1

Scott Hollenbeck
Muscle Car Research LLC
https://www.musclecarresearch.com/

erco
Posts: 334
Joined: Wed Apr 29, 2020 8:45 pm

Re: Brake pressure differential switch 67-69

Post by erco »

Just ordered a kit from Scott, will advise how it goes. I'm doing everything else to my brakes & front end so rebuilding this switch is the crowning touch. I'm surprised more people haven't chimed in here. Maybe since 90% of Corvairs only have single master cylinders then nobody cares. :chevy:

User avatar
azdave
Corvair of the Year
Corvair of the Year
Posts: 1957
Joined: Fri Dec 11, 2009 1:27 pm
Location: Phoenix, AZ

Re: Brake pressure differential switch 67-69

Post by azdave »

erco wrote:
Wed Sep 09, 2020 9:19 am
Maybe since 90% of Corvairs only have single master cylinders then nobody cares. :chevy:
Just not something I have ever needed myself. All of my Vairs are pre-67 and single MC.
Dave W. from Gilbert, AZ
65 Corsa 140/4
66 Corsa 140/4
66 Corsa 140/4 w/factory A/C
66 Corsa 455 Toro V8
65 Monza Convertible 110/4
66 Monza Convertible 140/4
65 Monza 4DR 140/PG w/factory A/C
65 Monza 4DR EJ20T/5

erco
Posts: 334
Joined: Wed Apr 29, 2020 8:45 pm

Re: Brake pressure differential switch 67-69

Post by erco »

Yes, that's an enviable motor pool of "early" LMs you have there, azdave!

erco
Posts: 334
Joined: Wed Apr 29, 2020 8:45 pm

Re: Brake pressure differential switch 67-69

Post by erco »

I rebuilt mine today, Scott's kit and tool were easy to use with the instructions on his website. My brass piston was fairly seized in the cast iron block. Only change was that I opted to re-use my springs since the ones in his kit were stiffer. Can't test just yet since the rest of the car is scattered, but I am confident that all went well.
Attachments
IMG_0454.JPG
IMG_0456.JPG
IMG_0461.JPG
IMG_0462.JPG
IMG_0466.JPG
IMG_0468.JPG

nirvairna
Posts: 19
Joined: Tue Jun 25, 2019 6:27 pm

Re: Brake pressure differential switch 67-69

Post by nirvairna »

well done erco :clap: :clap: :clap:

Post Reply

Return to “Corvair Talk”