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Engine Specific Info and Questions => IDI Engine => Topic started by: Rabbit79 on July 12, 2014, 09:40:22 pm
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So I was driving home the other night when a dog ran out in front of me and I had to throw on the binders really hard. Seemed like they grabbed just long enough for me to miss the dog and then the pedal went right to the floor and bam... no brakes after that. Nursed it home and took the master cylinder off and what has happened is I jammed on the brakes so hard the rod from the booster blew out the innards of the piston in the master cylinder. The end result of all this being I now have a booster full of brake fluid (well, about 1/3 full). I can't say that I really know a thing about the boosters as I've never worked on one and everything I've ever read about them says to just replace them if they go bad. So anyway my question is this: Does getting brake fluid in the booster ruin it? I was thinking I'd try to dump as much of the fluid out as I can, then put it in the solvent tank and squirt it out as best as possible with solvent then let it dry for a few days. Or would it be better to use something milder like soap and water? Or am I just wasting my time and need to get a new one? Suggestions? Opinions? Comments?
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A new one would be the safest choice.
Generally, brake boosters aren't "fixable".
I believe your master cylinder may be the issue as it should not let fluid get past it's seals and into the booster.
I'd change both.
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I already know the master cylinder is nuked. I just want to know if I can save the booster. I don't think there's anything really wrong with it except that it's got a bunch of brake fluid in it.
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If it were me I'd probably clean it out and try to run it. I would be careful about solvents though, you don't want to damage the rubber in the booster.
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It doesn't seem that solvent would be any worse than brake fluid, but then unless you're a chemical engineer (which I definitely am not), who can say what different chemicals will react to the different types of rubber or plastic inside the booster (or whatever else is in there). That's really why I put this post up in the first place. Brake fluid is nasty stuff, and I was just curious if it would be eating away at stuff inside the booster. Just hoping that maybe someone has come across something like this in the past and how it worked out for them.
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Years ago, I had a fluid loss issue with no trace of fluid, and i just kept topping it off It ended up the m/c was leaking into the booster. I siphoned all of the fluid out, replaced the m/c and was good.
Some time after, the return spring internal to the booster snapped or something. I cant say whether this was was attributed to the leak. The pedal wouldn't return to full height and the brakes would drag. I solved this with a bungee cord.
This was years ago, and the booster still works, although the ar is only driven maybe 200 miles per year.
-Todd
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I just did a complete brake sytem in my son's caddy
all new hardlines in s/s
new master
new booster
new flex lines
complete rebuild rear ( drum and cylinders )
new 16v calipers and 11'1 rotors
we did trim 1.5 inches off each side of axle, welded a gusset to the backplate, all leaf springs and axle were powdercoated satin black before install
If I did it again I would have switched over to a g60 calipers and a 26 mm master as its less money up front
the brake headlines ( s/s ) for the later cabby are easier to match then the early 20 mm system
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My MC also blew which resulted in fluid in the booster.
I drained all the fluid, did not use any solvents. 2 years ago on my daily driver no problems
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Hexed by this thread! I was installing my custom gauge holder in the dash today and was double checking the voltage to the solenoids for the WVO system under the hood and noticed my rear resevoir was empty. Looked out on the road and figured out that wasn't water draining out the wiper tray from last nights drizzle I was looking at. Dang to take it apart is a pain. But then so is not having rear brakes. Always something.
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This happened to an 82 jetta I junked that a family member daily drove. It was dumping fluid in their for months probably. I think I filled it with purple power and let it sit for a day and then cleaned it and blew it out with air. The one on my rabbit went and I wanted to put a new master in anyways, so I put the booster in and its still working.
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I was installing my custom gauge...
How meny man do you have???
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I think soapy water will clean out brake fluid,.. I think it's water soluable.
Sovents worry me when working with the brake system.
Most of the seals don't deal well with petroleum products. Not sure what the booster diaphram is made of.
Been a long time but I'm sure I've washed one out before and it worked great.
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Well it looks like getting brake fluid in the booster may not be as bad a thing as I thought it might be. I know with brake fluid you read all the warning labels that basically say don't let it touch anything, so you get the impression that it's pretty nasty stuff, but I can't say that I have any idea really what the chemical makeup of it is. What I've done so far is pulled the booster, squirted it full of Palmolive (don't want it to get dishpan hands you know), then stuck the garden hose in there and let it rip. As best I can tell everything looks ok in there. New master cylinder is supposed to be here tomorrow, so once I get it back together let's hope it works.
Sorry OR Coaster.... didn't mean to put the hex on you. :(
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That's what I get for trying to help I guess. If I spent less time here and more time up under the hood I would have noticed it before. Such is the case.
Mtrans. I work alone. Can't find anyone else willing to wrench on this thing with me. Maybe it isn't about the car?
Mtrans you will be the one to appreciate what I have going the most. The two pressure gauges at the bottom, Far right is engine oil but middle is IP pump running pressure. Top right is WVO fuel tank level, below that is normal VDO coolent temp, then volts. Nothing new there. Top left is vac/boost gauge on the Racor filter for the veg oil. Switches on the console are for the recirulation pump back to the WVO tank. Don't need heat all the time now do we? Two small switches are for the digital temp gauges in the dash. Blue is temp of fuel going into IP. Other red one cycles between channel 1 the temp in the tank and channel 2 the temp of the fuel going into the Racor filter.
Sorry these won't seem to flip even though that is the way Photo Bucket is showing them.
Finished product:
From the Drivers Seat
(http://i1087.photobucket.com/albums/j475/Orcoaster/IMG-20140713-00446_zpsc56811c1.jpg)
Somewhat Closer Inspection:
(http://i1087.photobucket.com/albums/j475/Orcoaster/IMG-20140713-00443_zpsab05f484.jpg)
(http://i1087.photobucket.com/albums/j475/Orcoaster/IMG-20140713-00442_zpsc5485449.jpg)
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FWIW, petroleum (or petroleum based solvents) will destroy the rubber in the booster in short order. The Palmolive was a good choice ;)
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Nice setup ORCoaster.On VVO you need that.
I just use one pressure gauge 0-2 bar to test my coalant sistem,for a week only.Best
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I don't know the chemistry for brake fluid, however what we do know: is brake fluid is hygroscopic, which means it rapidly attracts/absorbs water. And it also has to be good for rubber parts because the cups inside the MC are rubber & they practically last forever if taken care of. So washing with soapy water would be the right thing to do, chased by an ample amount of compressed air & THOROUGHLY dried, so it does not contaminate the fresh brake fluid with residual moisture.
I once knew a guy who used brake fluid as a tire dressing & his tires looked great. He said it had to dry somewhat after application so it wouldn't fling itself on the paint around the wheel wells.
Because it is so hygroscopic, I usually tape a bunch of desiccant packs around an open container lid, before putting it into a heavy ziplock bag to reduce the chance of water contamination. I think it works well.
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I had a mk1 jetta master cylinder leak a lot of fluid into the booster (because I kept topping off the MC not knowing what the problem was). With the MC off I siphoned out the brake fluid from the booster, then sprayed and filled it with water a few times to rinse the brake fluid out. I never took the booster off so it was a pain to siphon it out so many times; put on a new MC and never had a problem (had the car for about 5 years after that)
Brake fluid is easily rinsed off with water
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Thanks for all the help on the booster guys. That seems to have come out ok..... but.... this situation has just gone from bad to worse..... Got the new master cylinder on yesterday, and while bleeding the brakes I couldn't get any fluid back to the left rear. I'm like WTF?!?! Upon further investigation, I pull up the floor mat on the drivers side to see the carpet is a bit wet.... Ugh, not good... pull up the carpet and sure enough there's a pool of brake fluid on the floor. Turns out I also punched a little pinhole in the hard line that goes back to the left rear, right behind the clutch pedal. Oh joy!!! Thanks VW for running those inside the passenger cabin. I'm not sure if that hard line is one piece all the way to the back as I haven't pulled up all the carpet yet. That thing has got so many bends in it I don't see how they could have gotten it in there in one piece, but I'll have to see once I get the carpet up. Looks like the padding soaked up most of the fluid and the carpet isn't too bad, which is good because that padding is a lot easier to replace. For now it looks like I'm going to have to yard out the front half of the carpet and get it cleaned, strip down the floor pan and re-paint it, and get the brake line fixed. I found a kit for splicing in new brake line, so it looks like that is at least fixable without having to try and fish a whole new line in there (even if I could find one for a 79 Rabbit). Looks like I'm destined for some fun times. YEE-HA!!!!
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Your luck runneth over, In a bad sort of way. I hate to think what my situation is in this manner. I will have time to look this weekend if it don't rain.
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I don't know if you've ever messed with brake line before but the "easybend" stuff is real easy to work with and hard to kink.
Making the bubble flares is the hard part.
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Nice set up OR! every mans dream
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I don't know if you've ever messed with brake line before but the "easybend" stuff is real easy to work with and hard to kink.
Making the bubble flares is the hard part.
I'll keep that in mind Fatmobile. There's a union in the brake line right there by the B pillar, so if I could find an OEM line it doesn't look like it will be super hard to replace. Of course one of the pitfalls of owning a 35 year old car is it's getting harder and harder to find parts for it. I think most of the work here is going to be getting the floor pan cleaned up, the paint is all peeled up and it's quite a mess.
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To go forward on this
Does anybody know which range of vacuum is between vac pump and booster?
Can anyone verify info I get,that pressure after MC is from 5-8 bar.
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I ran a Vac gauge on the booster for awhile thinking it was my problem with low brake pedal. I was able to pull a 20 lb vac on it without a problem. A few quick brake pedals and it would drop to 10 but always came back real quick. I then replace the MC and that was in Sept. This weekend I yanked that one off and found my problem of the rear reservoir draining was due to bad seals on the rebuild. OReallys got that one back and I get another tomorrow.
I don't know about the pressure after MC, Where are you measuring? Pressure or Vacuum? What are we doing here?
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Thx
I also change MC and didn`t get good brake,I have it but something like booster or one way valve on him not working.You guess,I change booster one way valve and same thing again???
SO I think to find if VAC pump work on spec,or change booster or MC from shop is b......
ps.I was in hydraulic shop and gay that work there say that oil after MC is in range 5-8 bar.
I was thinking that is more,gremlin in my Fiat.
Best
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Is 20 lb= 1.37 bar?
by this http://www.google.rs/url?q=http://www.convertunits.com/from/lb/in%255E2/to/bar&sa=U&ei=qLjOU6vXD4H9ygPYwIHIAg&ved=0CBgQFjAB&usg=AFQjCNG7BqHbUzHbXvrnewPqZ0wrvEv63w (http://www.google.rs/url?q=http://www.convertunits.com/from/lb/in%255E2/to/bar&sa=U&ei=qLjOU6vXD4H9ygPYwIHIAg&ved=0CBgQFjAB&usg=AFQjCNG7BqHbUzHbXvrnewPqZ0wrvEv63w)
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converters never lie But liars convert.
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Is 20 lb= 1.37 bar?
Close enough...
http://en.wikipedia.org/wiki/Pressure_measurement#Units
(It's from the internet, so it must be true.)
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convert bar to psi multiply by 14.5.
I will just join the wash with water consensus. But finish with tipping out the water, add methylated spirits, (denatured alcohol?) and tip out, repeat a couple oif times. Flammable so if you die don't bother suing as I am boracic lint. ;)
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bar to psi is OK,but lb to bar/psi no no.
1.37 bar for pressure isn`t much,but for vacum is this mean that is lot?
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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!
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Rabbit79, You worry too much.
35 yrs and the lines got a leak, and some fluid came into the interior. I would have wiped it up, probably wouldn't have done anything else. How much of that floor board has some rust on it? If I was really into show cars and would have been pulling the seats out and the carpet out to show how the original paint is still intact I might have wiped the oil off with paint thinner, cleaned that with soap and water and painted it over once it dried.
Water is attracted to brake fluid. But enough to cause one to worry about rust? How many of us paint the MC and that is sitting out in the elements with fluid on it all the time.
Brake lines in the car? How silly? Just leave it alone. It is fine. Lines outside are higher risk in my mind. Rebuild them? Needless expense, even if you do add to the tool box. You are not going to need them again for 35 yrs. But you could loan them out in that time.
I like to tinker with these cars with the best of them but frankly, I think you are in overkill mode here.
DAS
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Well ORCoaster I'll be the first to admit that I get pretty obsessive/compulsive when it comes to working on the old Rabbit. Not because it's any kind of show car or anything like that. In fact it's very, very far from anything like that. I can tell you that stems from the fact that I absolutely HATE to have to tear back into something a few months or years down the road because I didn't fix it right the first time (kinda ruins the whole deal when you're mad at yourself the whole time you're working on something >:( ). To be honest I've had advice in all different directions on this thing. From "you better get that stuff out of there or it'll eat away your floor pan" to "ahh you got nothing to worry about". What I absolutely, positively DO NOT want to do is have to go in there 3 years from now and weld in a new floor pan, so I'm trying to err on the side of caution. And really cleaning up the floor pan wasn't that big a deal. I think I spent maybe 5 bucks on a can of paint and about 7 on some new carpet padding, and the rest of it was just elbow grease. As for the brake line stuff I have to get that anyway since I have to build a new one to replace the one with a hole in it Finding any kind of OEM replacement didn't pan out and nobody here in town makes them so I'm on my own in that regard. At present I plan to keep this car going until I'm dead, or they take my drivers license away, whichever comes first hehe. So it's entirely possible this problem could come up again.
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You got it under control then. I just replaced the MC on mine thanks to the fine warranty on the one I put in 10 mths ago. So sometimes you are back doing it all over again just because it failed for a different reason. I am hoping that this does not become an every 10 mth repair job. Oh, I shouldn't wish for that? It could become an every 30 day one.
I got brakes again and even was able to get the wife to help with the tinkering. Made the brake bleed go so much faster.
Good luck with the bender kit.
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So I know this is quite an old post, but it did end up being quite a saga that dragged on for a long time (mostly due to my own laziness I should interject at this point) and I thought I would show some resolution. I got the brake line situation fixed in a rather surprising fashion. I happened to be chatting with the head mechanic at, of all places, the local Ford dealership (he is a friend of mine), and the subject of my brake line came up, and he said we've got some brake line with metric ends, maybe we can make it work. So I took my old brake line to him and we measured it and it turned out be the exact same length, diameter, and have the same fittings on the ends as my VW line did. Perfect match. He loaned me his bending tools and I got that replaced quite easily. I never thought it would turn out that easy.
The booster side of the story turned out a little different. After I got everything put back together things were fine for a while and then all of sudden my vacuum pump started eating diaphragms. I never really did figure out what was causing this and if it was related in any way to the booster, but after a few years of rebuilding pumps every 3 months I got tired of that and put one of the new vane style pumps in. After this things switched to where I was getting vacuum assist only intermittently and then after a while to no vacuum assist at all. Being my somewhat lazy self I decided to just deal with it and went for like 5 years without any assist on the brakes. Here this past summer I finally decided to fix it and after checking around discovered that you can't get a new booster for a pre-80 Rabbit. Apparently they changed the way it hooks to the brake pedal in 1980 and post 80 boosters (which you can still get new by the way) won't work on a 79 or earlier version. I probably could have fabricated something if I'd had to but what I ended up doing was sending it in to Parts Place and they sent it to their rebuilder. Cost was about 275 dollars. Now.... Did getting all that brake fluid in there cause the booster to fail? I can't say on that because I had no contact with the rebuilder, so I don't know what they found when they went in there. I also have to take into account that it was 40 years old by the time it failed, so it could have been just natural wear and tear, but it did happen just not very long after it got filled full of brake fluid. It's unfortunate that I don't have a concrete conclusion on that but that's how it goes sometimes. Anyway, it's been in and working fine for about 6 months now (yes I did actually wait for awhile to make sure everything held up before posting).
Saga complete.
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I am reading this and the old posts thinking. While I was out tooling about the town I noticed a lack of brakes and the MC doesn't seem to hold when I push down and hold the pedal. It slowly sinks to the floor. So, maybe a bad seal in the MC.
Odd that my brakes act up as you update us that yours are finally fine. There must be some yin-yang thing going out there that some number of VWs must have bad brakes all the time to keep the planets in line or something.
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After I exorcised the brake demons from mine they were floating around searching for their next victim and apparently you were the closest. hehe
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Yesterday I got to tearing into an MC and proportional valve I found on Craigslist. MC looked pretty good and once I cleaned up the little bit of rust inside the bore I was able to bench bleed it and have it hold pressure with all ports sealed off.
The proportional valve was a different story. If you have ever had the chance to pull one apart the bottom tow caps are under heavy spring pressure and will shoot off at you if you are not prepared for that. I back them out a bit with the wrench then throw a rag over the end and slowly remove them all the while pushing down on the cap. I did this with the first one and sure enough right at the end it kind of sprang at me.
The other side was not pushing at me at all. Odd I thought and once I got it out of the valve body I saw that the spring was rusted up tight and I was just waiting for it to shoot the red valve stem across the room. I was able to pop it apart and clean it up without damage to man or valve. But that was the tightest I have ever seen a spring all rusted up like that.
Today I went out in the sleet and rain and checked on the booster before I tore off the old MC. I couldn't get it to hold a vacuum at all. I was only using a small volume hand pump and the weather got so bad I had to quit, or rather decided enough of this. I might try the old vacuum cleaner I use for the floors in the truck and see if I can get enough volume out and have it hold with that. The weather is not supposed to be much better for a few days so maybe next weekend.
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Today was a beautiful sunshiny day to work on the brakes again.
Yesterday I got off work an hour early so I used that daylight to pull the MC and booster off the truck. I found that the front seal on the booster was allowing air to sneak in next to the shaft that engages the MC. So I found a way to seal it up without buying a new front seal. I am not sure you can even do that.
I applied a vacuum on the booster and it held for a long time and was released when I pushed on the pedal shaft. OK got that part fixed and I had already gone through a second MC I bought off a guy on CL. So today I slapped it all back together and tested it out.
HMM mushy brakes, but I had yet to bleed them so I did that and I have a low pedal but not bad brakes. When I had the booster apart I tried to turn that little nut on the end and it just would not budge. So rather than break it off I am just going to live with brakes that are a bit lower to the floor than I would like them to be. Other than that they will send you rocking forward if you hit them with much force.
So, now to do something else with it. We are in for another 5 days of rain so I will have plenty of time to think about what I want to do next.
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So, now to do something else with it. We are in for another 5 days of rain so I will have plenty of time to think about what I want to do next.
Don't worry.... you know something will come up.
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Today I ran down to Bandon in my new Maverick. That hybrid is embarassing the VW with its stellar MPG. The creature comforts have it put to shame anyway.
Time to start doing yardwork, the sun will be out ALL WEEKEND. I may need to find some sunscreen and some shorts.