No fluid to rear brakes...

[frednoah]

Copy of post from my project thread, figured it might get more response as a separate post...

First up on the list of things to do: BRAKES

Truck had power brakes, and no where near enough vacuum to run them. Pedal was low and very hard. I decided to convert to manual. I bought a 1" bore master and fabbed a new push rod.

Bent a dozen or so brake lines replacing the front one I kinked relocating it. Finally got one I liked, and went to bleed the brakes. Fronts bled ok, I've got some stopping power now. Can't get a drop of anything out of the rear bleeders.

I've got no idea what the condition of the system is, I have only had the truck a few weeks. I did a search for "no fluid to rear brakes" and the results point to a stuck proportioning valve.

I've got a valve below my master, but I don't think it's a proportioning valve. My truck has 4 wheel drums, so what does that valve do? Could it be stuck like a proportioning valve causing me to lose the fluid flow to the back brakes?

My other suspect is the rubber hose ahead of the T out back. It looks newer than most of the other rubber under the truck, so I assumed at first it should be ok.

I drove the truck along the back roads to park it at my mother in laws house while i figure things out. Pedal goes almost to the floor on the first push, but pumping them 2-3 more times gets me enough pressure to stop the truck in about a 1/4 mile.

I bench bled the master before it went on the truck. I don't want to pull that valve off unless getting it fixed will allow me to bleed the rears and move on from there with any needed repairs.

Anyone have ideas?

[usmcchevy]

I had same thing happen. Rear brake hose was plugged solid.

[cdowns]

the distribution block is for drum brakes // theres a pin on it that needs to b clamped in place to allow fluid to the back system

[frednoah]

Originally Posted by cdowns

the distribution block is for drum brakes // theres a pin on it that needs to b clamped in place to allow fluid to the back system

Here's my distribution block. Would the pin be under the cover for the brake warning light wire?

[1968CHEVYC10]

the rubber hoses on my front brakes were clogged up when I re-did all my brake lines a few months ago. might be your problem. If you replace it make sure you get one thats long enough, there are different hoses for coil and leaf sprung rears. the guys at the parts store gave me the wrong one my first time around. and it wasn't to expensive I think about $16.

[usmcchevy]

If you have 4 wheel drums, there is no pin. The pin is only on disc brake trucks.

[mclairmo]

That is just a distribution block, no pin. The lines look wrong to me. For the fronts, you should have one line coming from the master to the block and then two lines coming out of the block to go to each front brake. For the rear, you should again have one line from the master to the distribution block, but you would only have one line coming out of the block and running to the back brakes. That's a total of five lines either going to or from that distribution block. You have only four. Looks like the hole in the distribution block for the line to the rear brakes is plugged with a bolt on your distribution block or that unused hole and thus, no line is going from it to the rear brakes. You need to plumb a hard line from that distribution block to the rear rubber brake hose or bypass it and go directly from the master to the rears.

[frednoah]

I think the lines out of the block are correct. The bolt on top was used in the power setup. There was a long thin bracket that went from booster to block and that top port is where it screwed in. Looked factory I thought.

Anyone have a pic of a factory manual drum setup?

[raycow]

The distribution block absolutely has a pin. That's what operates the switch. Is your brake warning light on now? If not, remove the wire from the switch, ground it, and see if the light goes on then (ignition switch on).