After changing out the master cylinder in my 68, I grabbed a bottle from the shelf and recharged the whole brake system with ... muriatic acid I have for cleaning the garage floor. So tomorrow I get to order a set of calipers, rear brake cylinders, soft lines and another new master cylinder.
Good thing I don't work on other people's cars.
Maybe I should offer to do a web site for the federal government. I may be over-qualified.
Hey, at least you figured out how to clean the rust from the inside of the old steel lines in the pan and test for pinholes...
Addendum to Newtons first law:
zero vehicles on jackstands, square gets a fresh 090 and 1911, cabby gets a blower.
EZ3.6 Vanagon after that.(mounted, needs everything finished) then Creamsicle.
I guarantee I got you beat. I have bought parts for a megasquirt build and KNOWLINGLY thrown them away (YES, ON PURPOSE) and bought them again because i get pissed off and blah blah blah. so yeah, dude, don't even worry about it. think about how stupid the average person is and 50% of the population is stupider! hahaha. i got 'em all beat.
Most likely your present rear wheel cylinders are 22.2mm (311 611 067C), but originally VW outfitted the drum-brake Squares with 23.8mm rear wheel cylinders (~15% larger area). The latter were adopted as fronts on the drum-brake Supers so they're readily available - 361 611 067A
Do you ever feel like the Squareback has too much forward brake bias (premature front lockup on slippery pavement)? If so, make the best of this situation and step up the rear W/C size.
Regardless, do be sure that both new parts are the same size- some parts-sellers aren't aware of the difference and sell both parts interchangeably for both Super front & Type III rear.
I don't imagine that the hard lines will be damaged any, and of course you're going to blow out/rinse them before closing up the system. Use up whatever DOT 3 fluid you have around while flushing and then get some DOT 4 (or 5.1 but NOT 5) as the final load.
Could be that you're being overly conservative and the rubber components would survive with aggressive flushing, but brakes is brakes and I imagine you don't live in the flatlands so I'll not try to change your mind about replacing them all.
Max Welton wrote:Today, it was quite a bit warmer and I could easily smell the difference. And since I wore 6 mil nitril gloves, I didn't burn my hands.
I hope the hard lines are OK.
Max
Isopropyl alcohol works very well to flush hard lines.
then compressed air to blow them dry.
If you are flushing acid, go water (profuse)>air >IPA>air> brake fluid.
It is a somewhat unusual deal for most to need to flush acid out of lines, but I have needed to do it at work from time to time.
Addendum to Newtons first law:
zero vehicles on jackstands, square gets a fresh 090 and 1911, cabby gets a blower.
EZ3.6 Vanagon after that.(mounted, needs everything finished) then Creamsicle.
OK, just finished replacing all the brake cylinders, front calipers, front flex hoses and the master cylinder. Not problems flushing out the reservoir, feeder lines and hard lines.
I cut open one of the front hoses and it didn't seem to have suffered noticeably so I elected to leave the rears in place for now. I do have a new pair of hoses for the rear. So I was able to get pressure in the system, but it requires some pumping every time. Probably still have some air in the lines, but I am leaving it till later this week. The next few days are pure family time.
I don't think the acid hurt anything, it doesn't affect rubber and only attacks the metal if has iron oxide (rust) on it, Aluminum is a different story. You are a shoe in to work for our government
Hey, at least you figured out how to clean the rust from the inside of the old steel lines in the pan and test for pinholes...
