Proportioning Valve

I am in the process of reassembling my jeep, and I need to determine where to put my proportioning valve. I did a front disk conversion early on. I plan to put the new MC on the frame at the original site because the new mounting bracket connects to the shaft fot the clutch and brake pedals and so I have access to fill it through the floorboard inspection window. My understanding is that the proportioning valve is necessary for two reasons - to maintain fluid pressure if the MC is at or below the level of the brakes and to be able to adjust the proportion of fluid going to front and rear brakes. Therefore, it needs to be somewhat accessible.

Where is the best place to install the PV? I have a dauntless engine with a power steering pump and headers and dual exhaust, but no other surprise equipment in the engine compartment like a heater.

Thanks.
-Fritz

 

I don't know if this the best place, but it works and keeps the valve up out of harms way. Mine is mounted on the frame cross-member behind the step up behind the seats.

 

Ok, let's break this down.
The proportioning valve reduces pressure from the inlet and outlet.
There are adjustable valves that go only on the rear line like Grant has shown. I have one on my frame rail under the seat (individual rear lines to rear disks)
If that is all you have read this:
https://shop.wilwood.com/blogs/news/how-does-a-proportioning-valve-work


Then there are combination valves that have front and rear lines. Those will be a little tricky with a frame mount master cylinder. I would put it on the frame where your front distribution block currently is. Yes your rear line will be longer but it will be in a safe place with minimal re work of your existing brake lines.

 

The residual pressure valve will not be in the combination valve, those are the red or blue inline cylinders or are built into the master cylinder. I would mount those away from heat (internal rubber duckbill) and between the master cylinder and any other valve.

Your hydraulic stoplight switch won't care where it is so just keep it away from the exhaust if it is needed and not part of a combination valve.

 

Thanks, guys. Makes sense. I got my kit from horsepowersales.com. It includes a dual reservoir frame mount MC and an adjustable proportionning valve with front in and out and rear in and out ports and a built in stop light switch (screen shot below). I have no brake lines remaining, so I have a lot of flexibility, but it sounds like the placement will be somewhere away from heat close enough to the MC to have brake lines running in a practical manner. This will probably be on the frame where my old distribution block was located. If I have a problem maintaining pressure in the lines, then I may need to look into whether I need to add residual pressure valves.

 

Here are two of the options on the frame. I can’t picture what would be blocking access since the tub is off.

Where the old distribution block was located. Downside is that I need to run rear lines farther up and then back again. Probably no big deal.


Closer to the MC. I think this will make the bends from the MC to the valve a little more difficult.


What do you guys think?

 

I hope to get to see that Jeep when you finish Fresbone! You going to take it to Pismo to get a head start on your new rust?

No practical experience re: your question, but I would think that in place of the original distribution block would be as good as anything else.
Once the tub is back on, all access will be limited.
Nice and clean now, then it should be your kid’s problem!

 

It’s definitely going to Pismo. It will probably live there several months out of the year. The funny thing about rust is that I blasted the tub a few weeks ago and was very confident about being able to take my time getting body work done because how hot and dry Fresno is. This has been the most humid summer I have experienced in Fresno and I already have some rust. I was planning to do a quick blast again after I am done with the body work. I know I will get no sympathy from the folks on the forum who do not live in a desert!

 

Yeah, we’re always moist here for summer, but you’re right, it’s been a bit more “tropical” even here at the beach.
Hope Hillary isn’t treating you to bad!