Wire/plug coming off my drum brake proportioning block?
 

Hi guys, can someone give me a summary of what the plug/wire is that’s coming off my brake proportioning block (4-wheel drum)?

I will be converting to front disk soon and I don’t recall the new proportioning blocks I’m looking at as having a place for a plug/wire…

Thank you,

Luke

Re: Wire/plug coming off my drum brake proportioning block?
 

It's the switch that trips the brake light on the gauge cluster when pressure in the front or back circuit drops and the differential pressure valve moves off center

All combination valves have them top center, AFAIK

Re: Wire/plug coming off my drum brake proportioning block?
 

Re: Wire/plug coming off my drum brake proportioning block?
 

Your post is confusing to me? You have 4 wheel drum and converting to drum? What switch does is already mentioned. Many aftermarket prop valves for disk/drum will just have a pressure switch that enables brake lights. It does not operate the same as stock.

Re: Wire/plug coming off my drum brake proportioning block?
 

Whoops meant front disk conversion. Typing too fast late last night.

Thanks for catching that

Re: Wire/plug coming off my drum brake proportioning block?
 

Perfect, thank you!

Re: Wire/plug coming off my drum brake proportioning block?
 

Also, just so you know, that wire is a "Grounding" wire for that particular dash light. If you
un-plug it and ground it out, the light should come on. When your brake fluid system malfunctions, it pushes to one side or the other and grounds out to light it.

Re: Wire/plug coming off my drum brake proportioning block?
 

FTR, when you get your new MC+Combo valve, put the little pluggy thingy into that same socket until you're done bleeding.

Wait to swap in the switch until you're sure you're done so that differential pressure slide can't move, impede flow, and generally p1ss you off

Re: Wire/plug coming off my drum brake proportioning block?
 

Rust is correct. If you are unfamiliar with these systems, they are very simple, and easy to learn. But....If you miss a step or don't understand the valve that trips the switch connected to the wire you are asking about, as Rust says, you will go nuts for days trying to "fix" or trace what you did wrong. Lots of posts on the subject, as it's easy to get caught is the shuttle valve trap.