sorry I posted in the meanwhile you were writting.

in order, once again:

the leak I got INITIALLY was at MC rear piston, not on the rest of the system ( what I'm aware ). That was the FIRST problem I tried to fix changing piston seals first ( didn't work ).

PARALLEL TO THIS got an irregular wear out at driver side brake pads what fixed meanwhile( replaced pads ) and tightened rotor.


One day noticed switch wire was unplugged ( maybe accidentally when replaced the seals, or maybe before that ), plugged and got light on ( most time on and quite often off sometimes when pressing brakes ) so I didn't know I had a problem there, and dunno really since WHEN I had the switch unplugged

Then replaced MC to fix the leak there on back... bleed and still got light on at cluster

Searching the problem for the light cluster reading, FOUND THE BRAKE FLUID SQUIRT I mentioned, below the hex at switch. Found the switch was MISTERIOUSLLY LOOSEN. Removed to check any failure. instaled back and tighten. I though leak there was solved since I didn't find was squirting again.

Got front brakes dragging for a while Light still lighting on frequently, went to a brakes shop replaced caliper seals thinking it was that, got light off.

Apparently the dragging problem wasn't the caliper seals because arriving home I felt again front brakes begining to dragg, so then adjusted the Rod as adviced... with that APARENTLY fixed the dragging, BUT light at cluster is again quite often ON.

Since light was still coming ON, made a CORRECT ORDER bleeding ( from longer to shorter distance ) thinking it could be that what I needed to reset the valve. Still getting light ON ( sometimes even with road/streets vibrations ). Searching for another problem, found the switch plug was wet with BRAKE FLUID what does mean the leak at switch is still there but not anymore below the hex, now at male terminal stud.

that's my situation now. Light at cluster ON around 50% of the time, sometimes just flashing and A LITTLE BIT UNCOMFORTABLE with brakes, even still able to block the brakes if needed.

all good ex for the warning light on most of the time & the slight leak? I'd open one side(not sure which one) & press the pedal to shift the valve back to the middle so it stays off & see if the leak looks fixable

for more exploded view, I can explain the diff on switch assemblies...

the one I have now is the replacement part This same one what I removed the bracket:


what carries the bottom switch on diagram I made and attached, and is "rebuildable" ( I can remove the central stud ), not like the tipical push in kind than originals pieces carries on what are sealed:



Kelsey Hayes in my case but switch is the same on Bendix too.

Now, I can replace the O ring at switch on the replacement piece.. fine, but I don't know if is normal to get a pressure enough to squirt or get wet at top of stud. IF IS NOT NORMAL because brake fluid shouldn't be running through the warning light piston section, then the problem is not really at switch O ring or assembly, and is more at pistons O rings or wherever inside the dist block assembly.

I couldn't find a leak on the rest of the system. haven't dissasembled the rear brakes, to check for wet areas at cilinder, but front deposit at MC ( rear wheels deposit ) IS AT SAME LEVEL SINCE EVER!

checked brake drums for adjustment and leaks... did need a small adjustment ( does the autoadjustment stuff really work ? ), but couldn't find any leak ( unles I'm blind ).

SO aparently the dist block/prop valve went bad JUST THREE YEARS ?

ANYWAY, PLEASE ONCE AGAIN. Is it normal to get pressure at switch section of dist block ? shouldn't be both systems isolated one from the other, rear and front, unless some problem on one of the system making a bypass by the prop valve ?

IT COULD BE THE PROP VALVE ITSELF damaged ( maybe spring went bad ? ) I'm able to repleace that section with another valve and spring from another prop valve, to check.

when I dissasembled the switch I was able to see the piston moved toward to rear.

front brakes are still dragging, just slightly, but still... at this point I dunno exactly what to do.

No, you shouldn't have brake fluid at the switch. There might be a small amount of residual leakage past the shuttle valve seals though. Slight drag ( you should be able to turn the wheels by hand easily ) of the front disc pads is normal. This is what keeps crap from between the pads and the rotors. If you can't turn the wheels by hand, fluid is not returning to the master. Check that you have some free play between the master push rod and the master front cup. Remove the switch. step on the brakes. If you have lots of fluid coming out of the switch hole, the porportioning valve is bad - 3 years old or not. Replace it. Do the warning light adjustment per Rapid Roberts post - after you have bled everything ( and it doesn't make any difference where you start your bleeding proceedure )and fixed any leaks.

thanks...

then definitelly prop valve came bad because is the ONLY leak I have. I'm thinking on the metering valve section stuck and thats why I'm having residual pressure at pads, AND switch piston is getting moved to turn on the light

I know about front brakes dragging, because I'm able to slightly smell the pads burning

According to my supplier, most of those repro iron prop valves are defective.

yes, but there is not another solution for a factory replacement unit ( beside used )

( I'm now thinking on a NOS unit being sold LOOONG TIME AGO! just a few months later I got the repro unit ) at the end nobody bid on it.

THERE SHOULD BE some way to rebuilt old units!!! I can't believe is not way to rebuilt it.

How can I get access to the piston ? removing rear brakes seat ?

My old one should just have O rings broken.