Hey,

Thanks to this forum for existing.

Apparently, it is impossible to find schematics for specific automobiles online. Kinda shocking, considering that I easily found the schematics to my 1970 BSA motorcycle in under 5 minutes of web searching. But a 2003 Buick Century? I'm hour 5 into my web search, and have decided to roll one up, create an account and post here in desperation.



That'* better.

So, I am redoing the brake lines on my 2003 3.1L V6 non-ABS equipped Buick century.

I need to know where the proportioning valves are supposed to be. Are there two inline with the rear brake lines, near the gas tank? Is there supposed to be a proportioning valve distributor mounted to the firewall? Is there supposed to be a proportioning valve built-in to the master cylinder?



So far (due to the rainy weather here), I've only managed to cut out one brake line (passenger, rear), and I've identified what appears to be 3 separate fittings along the line. I'm pretty sure that they are:

-a compression fitting splice (illegal!)
-a bubble flare fitting splice (that'* better)
-a mystery fitting that kinda looks like it might be some sort of bubble flare splice, though it is about half the length of the aforementioned bubble flare splice. (could this possibly be a proportioning valve!?)

Any help would be greatly appreciated.

this is a Dorman one that' fits your car

Dorman 905-952 Brake Proportioning Valve

item 51 on this brake lines shows location
W BRAKE LINES/ANTI-LOCK(JM4). Fits: Buick Century | Jeff Wyler Florence Buick GMC

just notice item 47 is one to same part number in line proportioning valve 2 inline
this looks like its the { mystery fitting that kinda looks like it might be some sort of bubble flare splice} your talking about

After reading my haynes manual a bit more thoroughly, it turns out that the proportioning valves are located in the master cylinder on non-ABS models.

The reason it'* hard to find service info online is because it'* all copyrighted and the factory charges big bucks for a factory service manual. As a ex dealer mechanic I feel your pain when trying to diagnose problems with out having the proper info needed.

on your car is there one on each that looks like the dorman picture???
you said some thing looked like a splice ?
{-a mystery fitting that kinda looks like it might be some sort of bubble flare splice}