Just replaced my master cylinder and booster. I'm still wanting to ditch the drums on the Dana 60 rear probably this winter while she's sitting in the barn. My question is how will the brakes perform without a proportioning valve or hydro boost, or would I need to do the valve immediately at the same time as the conversion? It may be a while before the hydro.

 

How come no pv?

 

That’s what I was wondering if I needed to do it at the exact same time as when I do the conversion?

 

70% of the braking is done by the front brakes. It does not sound like you are changing fronts. If the booster setup you have now works OK, it probably will work fine after the rear disc swap.

As far as prop valve, I think the OE style valve may not play well with rear discs. No valve at all may work OK or not... I don't know. Good idea to ask the supplier of the rear kit what is recommended.

 

You'll get different opinions on changing/keeping the OEM prop/metering valve on a rear disk conversion.....I did the rear disk switch quite a few years ago (no "kit"....made my own brackets and found some different calipers, etc) and used the OEM valve - no problems.

 

For optimal braking efficiency you need to change the proportioning valve and dump the factory one. .
Yes it will work with the stock one but if you are not going to change that might as well stay with the drums as you wont be increasing your braking efficiency at all and may actually reduce by leaving the factory one in place and swapping to disks. .

 

Is there a direct replacement valve that bolts up to existing lines that's adjustable? Or would new lines need to be fabbed up?

 

99% sure no direct repl. with adj. feature. Wilwood baer, to name a couple,, but the light switch is for brake lights not a failure indicator.

 

In all likelihood no. But you may be able to bend the existing lines to fit. It is a tough question to answer with out seeing what you currently have.
There are after market adjustable prop valves/distribution blocks available such as.

Adjustable Proportioning Valve Block, Brake Distribution System

and

https://www.summitracing.com/int/par...v-db/overview/


Either of these will replace the existing combination valve allow you to dial in the brake bias for maximum effectiveness.
Note if you set it unloaded you will not have as effective rear braking for when the truck is loaded. If you set when it is unloaded you will lock up the
rear end unloaded.

You can mark the prop valve for loaded and unloaded and adjust accordingly. The factory system is set up to balance between loaded and unloaded and generally will lock up the rears in a panic stop when unloaded.
This was part of the reason for going to Anti Lock brake on the rear of trucks in 87, to allow for better braking loaded and unloaded.

Prior to the use of Anti lock Ford had an adjustable prop valve on the rear brake circuit in some applications to combat this issue, The prop valve was fixed to the frame of the vehicle and had an arm to the the rear axle and as the truck/van was loaded down the arm moved up and it increased the braking effort on the rear axle.


The down and dirty option is to gut the prop valve out the existing combination valve and add a 2 port proportioning valve (see link) after the combination valve for the rear's

https://www.summitracing.com/int/par...pv01/overview/

 

I just made the conversion with a kit purchased from a guy out of TN. Lugnut 4x4. You can piecemeal it together from the parts store cheaper but I liked how it all showed up to my door 100% complete. I opted for the calipers with the emergency brake. The brakes work great and seem to be balanced. They don't try to lock up on me when it rains or anything crazy. I did not install a proportioning valve.