Seems like I remember reading or hearing somewhere that for vacuum you should be pulling somewhere in the range of 25 to 30 inches. A few times in the past when my vacuum pump is fresh off a rebuild I've put the gauge on it and usually get around 28 in/hg.
As for my original situation on this post, here's where I'm at...... My biggest concern on this whole deal is what all that brake fluid will do to my floor pan, as in will it corrode the floor pan to nothing-ness eventually. My floor pans are in pretty good shape for a 79, and I'd like to keep them that way. I know brake fluid will strip off paint in a hurry, but beyond that I can't say I really know a whole lot about the stuff. I'd have to say that what I know about brake fluid has been picked up from talking with other shade tree mechanics and parts guys over the years, and I've always had the impression it's pretty bad stuff towards metal. However that sort of information can be all over the place, and probably not have much in the way of concrete data. One of the guys up at the local parts store even told me you should clean brake fluid off of metal with acid! I've been trying to read up on it but information is kinda sketchy. I did find a material safety data sheet which had the word 'oxidizer' in it, which from what I know about MSDS's (which isn't much really) can mean corrosive. As far as I know the floor pans are made of just plain steel, but then I think, so to, are the brake lines. Whether or not brake lines have some material alloyed in with them to resist any corrosive properties of brake fluid I can't say, but they look like just plain steel to me. One thing I did read about that seems to be a consensus is that brake fluid attracts water (as a previous poster has already said), which as we all know is corrosive to steel. I suspect that inside the sealed brake system that's not too much of a worry but once it's out in the open air then it becomes a problem, as it absorbs moisture right out of the air.
So..... Armed with what knowledge I could find on brake fluid corrosiveness, here's what I've done so far. First of all there's a thick coating that covers most of the floor pan. It looks like that rubberized undercoating stuff they spray on the bottoms of cars and use for bed liners for trucks and such. It's laid on pretty thick, about a 1/4 of an inch or so. I think luckily most of the brake fluid drained onto it. After sopping up as much brake fluid as I could with paper towels I hosed the crap out of the floor pan with Purple Power and hit it with a scrub brush. The paint was all gone around the edges of the coating, but there wasn't much rust to speak of. I had some heavier rust up by the accelerator and clutch pedals, and some lighter rust back by the cross member that runs under the seat. The lighter stuff I hit with some naval jelly and the heavier stuff with a wire brush on a drill. Got it all down to bare metal and put on a coat of primer and 2 coats of paint..... Hopefully it will last. The carpet wasn't too bad. It just had a couple little spots where fluid had soaked in, so I took it up to the car wash and gave it a good hosing down, and it came out fine. The padding was completely soaked with brake fluid..... It now resides at the Harney County dump. Got some new padding from the local carpet store and I might also put in some sort of insulation under the padding when it all goes back in.
As for the brake lines I can't say that I think much of VWs idea of running them inside the passenger cabin, for the very reason of the problem I'm having now, although I suppose they had their reasons. I suspect maybe they didn't want them to get torn up by road debris if they'd run them underneath, although the fuel lines run underneath the car and I can't say I've ever had a problem with them. The line for the right rear brake is especially retarded. It runs from the master cylinder across the firewall to the right side, into the passenger cabin and down the right side of it, then exits the passenger cabin underneath the back seat and runs back across the car to the proportioning valve which is just in front of the left wheel well, and then back across to the right rear wheel. I also imagine they didn't think this old girl would still be on the road 35 years after leaving the factory, so they probably didn't think this problem would ever come up. After some research I've found some kits that enable you to make your own brake lines. They're a bit on the spendy side after you add in the flaring tools and everything, but hey I'm never opposed to the idea of adding new tools to the shop. My current plan is to take out the factory installed brake lines for both rear wheels and then make new ones that will run down the drivers side just like the fuel lines run on the passenger side. If nothing else running them outside the passenger cabin will keep me from having to deal with this mess again. Yay!
Topic: Booster full of brake fluid (Read 7848 times)
