Proportioning valve thread sizes HELP!!

*98' 4.0 4x4 NO ABS 5 speed manual*

Okay so I'm replacing the hard brake lines on my jeep and i have a couple questions.

For starters i'm not replacing the hardlines from the master cylinder to the proportioning valve. rather i am replacing all the other lines from the wheels till they meet the proportioning valve.

Starting at the prop valve, going out of it to the rear line, there is like 6" of brake line then a union!? and then the large length of rear line goes from there all the way to the rear axle. whats up w/ this union?

also the nuts that go out of the proportioning valve to the wheels...they seem like huge nuts :roflmaowhere the wrench goes) compared to the nuts on my preflared 3/16" line? is the thread and pitch the same though? b/c its still using the same 3/16" line. meaning can i just unbolt those and bolt in some double flared 3/16" line.

I've heard various sources say there are bubble flares used on the master cylinder and on that union i spoke earlier about.... getting confused want to get my ducks in a row before i tackle this tomorrow. i need to know if i need to get ready to start cutting off preflared, flares, and re-flare to bubble.

Can someone please just tell me....

-where if any are there bubble flares.

-what part of the brake system does not use the double flared standard size nut thats included on preflared 3/16" line?

I don't know 100% on what the flare nut sizes are going to be. If you figure that out, you can buy ready-made lines with bubble, double, metric, or SAE threads at either end at Napa.

Alternatively, you can clean up and reuse the existing nuts, but that obviously means reflaring the ends of the ready made lined. The first step of making a double flare is making a bubble, so a bubble flare is actually easier than the double. Buy or rent a flaring kit. Sears has a decent one for $20.

Here are the Chrysler Part numbers for a 4wd. Looks like about $40 from http://www.chryslerpartsdirect.com for the set. The parts diagram shows that union, so its a stock setup.

52128381 Proportioning Valve to Front Left $8
52127988AC Proportioning Valve to Front Right $8
52127967 TUBE, Brake, Union to Rear $26

Alright, well i just finished this job. i could smack jeep for making things so retarded. Lets see... we'll have at least two different thread sizes that go into the proportioning valve. (1/2" and the standard size for a regular 3/16" line nut) we'll have one brake line have a bubble flare on one end and a double flare on the other. then we'll have nuts with the same outside size (where you put the wrench) however the threads will be different sizes... uhhh anyway, i completed the job. did all the hard lines except the ones that go from the wheel cylinders to the center brake line...since they appear to be in great shape (IE were replaced within the past year by the previous owner). did all the soft lines as well. trick setup jeep did to have the axle breather double as the hold down for the brake line...slick.

for how simple this truck seems to be there are things like this brake line B.S. that make you go :smsoap: