Yesterday I converted my '75 K10 to hydroboost from a '79 C30. the master cylinder from the C30 had the LARGER brake line to the front and the smaller on to the rear. The '75 was just the opposite-small up front larger in rear. I looked at both proportion valves and they seem to be identicle. Anybody have any pics of the RIGHT way to hook up the brake lines? Thanks
-Lance
Ack... trying to remember this, I went through this.
The small line goes to the larger reservoir, so IIRC that's the rear brakes, the drums (take more fluid than disc.)
The larger line goes to the smaller reservoir on the master, so that should be the fronts.
I've seen masters with the front brake output in the back, and I've seen them with the same output in the front. You'd think the front brakes would always go closest to the booster, but this is not the case.
SOOO, I *think* you just hook the lines up wherever they fit and it'll be correct for your master -- I assume this is why GM 'keyed' the lines this way. It'll take some fiddling with the lines, but it's doable. GM left us those nice coils in the factory ones for some flexibility.
Worst case you can trace the lines to the combo (prop) valve ... IIRC there are three right together, which are the fronts, and then a separate pair, which is the rear. Trace the front one up, and it wants go to whichever port on the master has the smaller reservoir.
Hopefully that all makes sense; if not, post a pic of your master and I'll go look at my trucks and give forth my expert prognostication
)
-- A
