Rear drum brake residual valve

[igniter3]

Hello folks,

I have question about the pressure valve or a one way valve for the rear drum brake on my 79 Fj40.
Just bought the truck last month and notice there is no brake fluid flow to the rear drum brake , no brake fluid flow out of the one way valve (pressure valve).
Take the valve off and clean bunch of junk out of the valve, remove the spring, the piston and the seal like a little cup for good cleaning and still not working.
My question is when I removed the piston, the seal cup is pointing downward.
Anyone know if the seal cup should be pointing upward? so the fluid can flow through the valve and should block the flow from coming back?
This valve has an arrow for directional flow just like a check valve.
I installed the piston without the seal cup than I have brake fluid flow through the valve. Tested drive around the block,now I have too much fluid flow to the rear drum brake and cause the rear drum to lock when the brake paddle is apply.
Any help will be greatly appreciated.
Thank,

Charly

 

[igniter3]

Here is few picture of the pressure or directional valve of the 1979 FJ40 for the rear drum brake to share......

 

[igniter3]

Few more.....
Took the valve off again to day, re-installed the seal cup back on and took the
residual valve off for cleaning, put every things back together and work great....

 

[igniter3]

The residual valve for the rear drum brake on the master cylinder has #2 on it.
Does that #2 mean any thing?

 

[DougAustinTx]

The photos you posted are of the proportioning valve. That is not the same thing as a residual pressure valve.

The proportioning valve regulates the amount of pressure going to the rear wheels so that they don't lock up when the weight of the car shifts forward in a quick stop. You always want more braking to the front wheels than the rears with a front engine automobile. If the rears lock up first, you stand a good chance of sliding or losing control in a panic stop.

The residual valve is in the master cylinder and it prevents the brake shoes from backing way off the brake drum between uses, by keeping a small amount of pressure on the brake cylinders. However, if you keep your brake shoes adjusted fairly tightly to the drums, the residual valve has little, if any, effect.

I can't tell from the photo exactly what the item is with the number 2 on it. There is supposed to be a rubber cushion inside the big nut on the proportioning valve. Yours may be there and just not visible in the photo. Here is the URL to a thread I did a while back on my proportioning valve:
https://forum.ih8mud.com/40-55-series-tech/707139-proportioning-valve-photos-disassembled.html

 

[igniter3]

OK, my proportioning valve is the same as the one you have on your cruiser.
The white plastic with the #2 on it is from the residual valve on the master cylinder.
I did not take picture on the underside of that white plastic, it does have spring and a locking plate to hold the spring in place. I notice your master cylinder does not have that residual valve.
see attached photo.

 

[igniter3]

just another picture may tells better...