Question about my hydroboost brake system

[Yukon Jack]

On my 1969 K20, when I put in the 454, I also put in the hydroboost system from the donor 1989 1 ton 2wd truck. My 69 K20 had a manual brake system, drums all around.

When I put in the hydroboost, for what ever reason I did away with the block that you see in the below pic shown on the old system so the hydroboost front brake line went directly to the factory splitter that than sends it to the left and right brakes. The rear line just goes straight to the rear brakes.



I'm installing a Dana 60 front axle from a 1984 Crew cab which will of course gain me front disk breaks (can't wait for that improvement!!!!) I'm presuming I will need to add an adjustable proportioning valve on the rear brake line.

I've read some people mention when they add disk brakes they have to add a 2 lb residual valve.

Here is the existing hydroboost installed in my 69 K20



In looking at pics of the hydroboost before I pulled it from the donor truck, I can't find any pics that show whether a proportioning valve was somewhere within the system.

Can anyone shed some light on my situation so I can figure out what changes I need to make to my existing system. I would add, when it's time to have brake work done on the existing rear Eaton axle, I will probably swap disk brakes instead of keeping the drum brakes as I've heard brake pads are a bit difficult to find for that axle.

I will note the all drum system was working fine with the hydroboost as I had it set up, but I am a little confused on why I didn't put the factory block shown in the above pic into the hydroboost system or maybe put in the donor trucks proportioning valve (assuming a 1989 1 ton 2wd would have had a proportioning valve). I do recognize that my existing system does not have a sensor that allows an idiot light to light up if the system were to fail or lose pressure.

[cparman]

the block on the original brakes is just a distribution block, not a prop valve

The 2lb residual valve is needed IF the master cylinder is located below the brake calipers or wheel cylinders. In other words if you were to mount the master/booster under the floorboard you would need residual valves

IMO after the disc brake diff install you will need a disc/drum proportioning valve to have great stoppers

[el curioso]

i just added an original 72 proportioning valve works great.

[Yukon Jack]

Thanks guys! I'll get one ordered.

[19704x4]

I know I'm a little late, but I did a 44 and 14bolt swap on my 70 and went from manual 4wheel drums to 4wheel disc brakes. I use the same Hydroboost setup you used, however I ordered a disc/disc proportioning valve online that took the place of the old distribution block. The same valve is made for disc/drum applications. just Google it.