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desperate attempt to fix overheating


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Dear managers and members please delete this thread if you choose, ignore, or otherwise deny or place in the appropriate forum. If so, please let me know where, so I can update my findings. Assuming anyone is interested.

 

Re: notorious subaru head gasket failure coolant overheat problem. I thought I’d let you know how desperate I am and how using brake fluid for coolant worked the first and only time I’ve tested it so far. It didn’t over heat for an hour and a half continuous multi speed driving with one stop to idle at wendy’s. I’m not recommending it but thought you would find it interesting. After I post this I’m going out for another hour and a half mostly highway. I'll let you know what disasters if any happen and whether I’m still alive. If I don’t post again you know what happened and how to act accordingly. Even if I post again you shouldn’t try this. I beg you not to try something this crazy and foolish. But, if I've entertained, something good came out of it. My loss your gain. I mean it, don’t do this!!!! You might be exploded, you might die or be crippled, maimed and blinded for life and everyone around you for a 15 mile radius. This is extreme experimenting.

 

So, I had typical head gasket failure overheats and bubbles in the reservoir. Intermittent over heating. But finally it would over heat after about 15 minutes local street driving.

 

In desperation ‘cause I’m broke and I love this car I decided on the apocalyptic method of survival, since lately it’s been feeling kind of apocalyptic in the world, thought it was appropriate. Instead of throwing the car away because new head gaskets are so expensive and such a cost benefit gamble I decided to experiment with brake fluid as a coolant. As opposed to mineral oil. I dried out the system with a hair dryer and warming the engine without coolant to about the normal temperature to get as much moisture out the system as possible while running the hair dryer stuck in the thermostat hole on high heat and high volume.

 

I took it out for an experimental drive with brake fluid for coolant today and it worked fine for an hour and a half drive. Hasn't gone more than 20 minutes without overheating previously. Just enough time to get to work. I drove the experiment at highway and street speeds. It took a long time for the fans to finally come on after the temp gauge went above normal but not too far. When the fans came on the temp came down to normal. It only peaked twice and generally stayed normal. I’m willing to drive it even if the gauge is above normal a little but I didn’t have to. Don’t know why it didn’t spike again. Could be there was some water in the block and it boiled off. But really don’t know but am very happy about no overheating when yesterday it was overheating every ten minutes. Overheating meaning serious high temp spike which ‘causes me to stop, kill engine and open hood and cool engine for 15 minutes.

 

 

Why brake fluid? Brake fluid is similar to glycerol and it has a high boiling point and flash point and autoignition temperature. Better than mineral oil in that regard. I’m iffy about how the brake fluid will treat the aluminum but the master cylinder is aluminum so what the heck, brake fluid is supposed to have corrosion inhibitors for steel, at least, maybe it will work for aluminum too. Concerned about Aluminum in in the engine and the new radiator core and nylon might suffer from brake fluid too for that matter, and also rubber heating hoses, and aluminum in heater core. I figured there's rubber in the brake lines and cylinders so chose that over mineral oil because I think mineral oil is likely to hurt the hoses. Also radiator hoses handle antifreeze, ethylene glyclol, break fluid is diethylene glycol. Might treat radiator hoses just as well. Don’t know for sure and may try mineral oil if the brake fluid worries me that way or for other reasons. Also may abandon the whole experiment and the car. We’ll see.

 

I also decided on brake fluid over mineral oil because it has a higher specific gravity than water and antifreeze, oil has a lower gravity. I reasoned more density would transfer heat better. And a higher boiling point would keep the boiling down which kills heat transfer. Plus I'll keep it pressurized and thermostated which should raise the boiling point even more. I hope there will be no explosions which is why you should never ever try this hair brained idea. Let me do it for you. I’ve always been a risk taker. Brake fluid is flamable and has an flashpoint. But, so does antifreeze. And mineral oil. Brake fluid is higher. And again I think what the heck.

 

 

While I was filling it before I took it for the hour and a half test drive. I ran the engine and heated up the brake fluid I'd gotten in there. I got a very high spike in the heat gage after about a half hour idling while slowly filling to top off the brake fluid. I wanted the thermostat to open. Fans came on but spike did not come down disappointing, but I did notice the engine did not sound over heated. I turned off engine and kept filling with microwave heated brake fluid figuring what the heck I’m in this far. I stopped the microwave every minute and opened cap to release any pressure. I warmed a quart of it to about 100 degrees in 4 minutes. Used that to top the radiator to the brim. It took a while but I got there. I have reservoir in line as is typical so took that out to get all moisture out and rinsed it with a little break fluid and dumped that with any moisture the couple ounces of brake fluid could grab, and reinstalled. Dot 4 Brake fluid $4.50 a quart loves moisture so I will have to deal with that if I keep the brake fluid in. I figured if I put the cap on the first click in wouldn’t hold pressure and the water might steam off into the reservoir before the break fluid does. Otherwise I might let the over flow dump on the ground for a trip or so once a month to get moisture out. Haven’t decided yet. Don’t even know if the experiment will last for month or not but I’m encouraged by today’s foray. I’ll keep you posted. dadob

Edited by dadob
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thats nuts! I got to say that you are going to have a lot of people give you crap about this but I have to say I'm curious how this is going to work out. Good luck and don't die on us :lol:

 

Make sure you don't get that stuff on the paint or that will be ruined.

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wow, that's awesome willingness to try.

 

since you're willing to experiment there's also a $4 radiator cap you could use to alleviate the issues and keep the car driveable without overheating. it has a special valve to release the exhaust gases in the coolant and allows coolant to flow normally and not overheat. still a band aid but probably the best bet if this is a DOHC EJ25. - you don't mention what vehicle or engine this is?

 

brake fluid is rather corrosive but you know that. i would think it's going to degrade something. i just replaced a master cylinder that's been leaking for like a year or two - and everything under it was eaten up pretty good. i have spilled brake fluid all over stuff before and never saw it do anything, but this prolonged contact definitely showed it's corosiveness.

Edited by grossgary
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:eek:

 

Well - you're thinking outside the box - that's good.

 

My biggest worry would be the rubber in the hoses, etc - brake line rubber is special stuff and "normal" rubber will swell and soften around brake fluid. I don't know how different the formulations are for brake line vs. coolant line but that would be my biggest concern for sure.

 

I think I would have tried one of the block sealer products first, but this is an innovative idea. I'm curious about why this works at all - what effect is the brake fluid having on the "leak" that's causing it to not longer be an issue. Being that your failure is one where the combustion gasses are entering the cooling system.... how does the brake fluid prevent this?

 

Also - if you can scrape together the funds for the head gaskets, intake gaskets, and exhaust gaskets - the rest is pretty much labor. There's a lot of other stuff that you *should* replace while you are in there but it's not neccesary if you are broke. But having a place to do it and the tools is also a concern...... I'm just saying the job could be done for about $100 in gaskets (the head gaskets are $35 each) if you are careful and smart about it. Maybe even that's too much for you right now ?

 

GD

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i do believe the only difference in hoses between coolant and hydraulic (brake) is extra reinforcement for higher pressure. mainly thicker rubber with more nylon. what i would be worried about is heat dissipation. normally its mixed water/coolant cause antifreeze does not dissipate heat very well which is why its mixed with water. does brake fluid transfer heat at all?

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The brake fluid will cause the rubber hoses to soften, swell and burst, spraying heated fluid everywhere. It's a matter of when, not if they fail.

 

If anyone doubts this, get a section of rubber coolant hose, put it in a container of brake fluid and let it sit for a week. You'll see how soft it gets and how much it swells up.

 

You're also going to ruin the seals in the water pump and that is going to fail.

Edited by subaru360
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The brake fluid will cause the rubber hoses to soften, swell and burst, spraying heated fluid everywhere. It's a matter of when, not if they fail.

 

I'm thinking the same thing. And the cost of the hoses is going to add up to more than the cost of changing the gaskets. The water pump might last for a bit since it uses a mechanical shaft seal on the inside..... but eventually that will get destroyed also I think because the brake fluid will attack something in there :(

 

GD

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Well I made it back. Remember two days ago I was over heating driving less than 10 miles. 80 more miles highway driving, it spiked a couple of times but came down when the fans came on. I’ve decided to run the fans constantly. I turn on the air conditioner and pulled the right ac relay when the ac clutch is engaged. Have to be quick. Fans stay on compressor goes off.

update: this trick resets every time you turn off the car. You folks have any other ideas how to make this happen? dadob

 

Answering a few questions: Etheylene glycol antifreeze and diethylene glycol brake fluid are cousins. Hoping the hoses won’t suffer any worse than from antifreeze.

 

I am watching for coolant loss, I should see serious smoke out the tailpipe if I’m burning some. I was hoping all my antifreeze loss was unseen reservoir overflow while driving. The reservoir often topped out with antifreeze. Not getting much in reservoir with brake fluid. But coolant was a few ounces down. Hoping that’s just from left over trapped air coming out.

 

I expect that the head gasket leak will heat the brake fluid just as much as before but it shouldn’t boil if it stays under 4 or 5 hundred degrees. The anitfreeze can’t take 300. Boiling is my target. Stopping it.

Wether the engine can take 4 or 5 hundred is unknown. So far temp guage is normal except for spikes.

 

I did try it un pressurized (loosened the cap) didn’t work too well. Pressurized definitely better so far. It should raise the boiling point too.

 

If I need to I’m going to put my gutted thermostat back in with the seal to increase fluid pumping speed. I snipped the guts out of a thermostat and put the skeleton back in so the seal would work. I may get the better water pump I’ve heard about and change the timing belt if this makes it to spring. Not very hopeful but gonna try.

 

That’s why I haven’t popped for do it yourself head gasket repair. I figure it’s gonna be a 4-6 day slog removing the engine and being tempted to do more stuff while it’s out. Too cold, can’t face it. Trying to limp it along till spring. Maybe in the spring I’ll do the gaskets. I love this car.

 

Spikes may be caused by intermittent head gasket heating that’s been reported by others. So far I have been able to handle it. I have noticed best effect using heater on high in vent/floor vent mode. I open the windows cause it really gets hot in here.

 

WARNING OFF THE SUBJECT A MINUTE. In my research a found out a lot of people have suffered horrible kidney failure deaths in the last hundred years from foods, syrups, gelcaps etc. when unscrupulous manfacturers use cheaper brake fluid instead of bonifide more expensive non poisonous glycerine also called glycol. Glycol is used as a food sweetener, it’s a sugar alcohol. So don’t buy sweet food and medicines from third world countries or dollar stores in new york that had counterfeit Colgate for a buck with DEP (brake fluid) in it and listed on the label!!!!.

 

 

I’ll post in a week or so with update. Thanks for the encouragement and the warnings. That's why i posted. Your opinions are important to me. I'm listening. dadob

Edited by dadob
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GROSSGARY EDITED ....since you're willing to experiment there's also a $4 radiator cap you could use to alleviate the issues and keep the car driveable without overheating. it has a special valve to release the exhaust gases in the coolant and allows coolant to flow normally and not overheat. still a band aid but probably the best bet if this is a DOHC EJ25. - you don't mention what vehicle or engine this is?

 

 

GROSSGARY where can I get that cap???? I like it. TYPE 1 ENGINE I THINK 97 OHC LEGACY OUTBACK

 

"brake fluid is rather corrosive but you know that."

 

It's possible the corrosion was caused by water in the brake fluid. Brake fluid is like a water vacuum. Just opening the cap to inspect the master cylinder can add a tiny bit of water if it's humid. dadob

Edited by dadob
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subaru360 quoted The brake fluid will cause the rubber hoses to soften, swell and burst, spraying heated fluid everywhere. It's a matter of when, not if they fail.

 

If anyone doubts this, get a section of rubber coolant hose, put it in a container of brake fluid and let it sit for a week. You'll see how soft it gets and how much it swells up.

 

You're also going to ruin the seals in the water pump and that is going to fail.

 

subaru360 You may be right. I'm hearing you and watching close. I did put some pieces of radiator hose in a bag of brake fluid. So far no discoloration of liquid, nor softening of rubber. But it's only been a couple of days and then hot brake fluid is probably harder on the rubber. But I still figure ethylene glycol and diehtylene glycol ought to have similar effects on radiator hose. Lord have mercy. thanks dadob

Edited by dadob
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Why not have used a can of block selaer? this may have fixed it. Or at least run less hot.

I'm afraid the brake fluid is a fire hazard if a hose blows out and it gets on the exhaust. Keep a fire extinguisher on board.

 

Thanks Miles fire extinguisher good idea. Will do.

 

Block sealed twice no effect. I even tried block seal for 500 miles with only water no antifreeze this recent summer. There's someone on the web who wrote a long piece about that method of block sealing. I like his idea but it didn't work this time.

 

Antifreeze can burn too. Has similar properties to brake fluid. Of course the 50% water probably helps that. Anyway I'll watch it carefully. dadob

Edited by dadob
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I'm thinking the same thing. And the cost of the hoses is going to add up to more than the cost of changing the gaskets. The water pump might last for a bit since it uses a mechanical shaft seal on the inside..... but eventually that will get destroyed also I think because the brake fluid will attack something in there :(

 

GD

 

took thermostat out and put in my gutted thermostat dummy and seal. No spiking today but runs cooler than I want. Might put cardboard in front of half of radiator.

 

GeneralDisorder do you know for sure the water pump has a rubber seal or could it have a metal on metal close tolerance bearing seal? dadob. I'm watching it.

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I had the head gasket problems, bubbling in reservoir and overheating. Gutting the thermostat will keep it or at least it kept mine from over heating and with no change of antifreeze to brake fluid. On a down hill run the temp will drop but that would be normal without a thermostat. I don't know how long this will work or what possibly could be damaged as I replaced the head gaskets on mine. I would go this way and stay away from the brake fluid. Good luck!

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I'm just curiouse if there is a reason for gutting the thermostat instead of just completely removing it as I have had cars in the past where the thermostat went bad and I just pulled it and left it out the car runs a bit cooler and you normally have to block half the radiator in the winter but I would never have wasted my time trying to gut one so im just wondering if there is a specific reason for all the extra effort?

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I'm just curiouse if there is a reason for gutting the thermostat instead of just completely removing it as I have had cars in the past where the thermostat went bad and I just pulled it and left it out the car runs a bit cooler and you normally have to block half the radiator in the winter but I would never have wasted my time trying to gut one so im just wondering if there is a specific reason for all the extra effort?

 

 

 

hi dakwing

 

on my subaru there's rubber gasket that stretches over the edges of the gasket. i didn't know any other way to seal it depedably.

 

Also if you want maximum flow which is I wanted, gutting it is better.

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I had the head gasket problems, bubbling in reservoir and overheating. Gutting the thermostat will keep it or at least it kept mine from over heating and with no change of antifreeze to brake fluid. On a down hill run the temp will drop but that would be normal without a thermostat. I don't know how long this will work or what possibly could be damaged as I replaced the head gaskets on mine. I would go this way and stay away from the brake fluid. Good luck!

 

i.m thinking you're right about the antifreeze being okay with the gutted thermostat. I may end up trying that. So far the brake fluid experiment is interesting enough to proceed. dadob

 

I can't remember if tried the gutted thermostat with the antifreeze before I got deperate and tried the brake fluid. The joke would be on me. dadob

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I can confirm that a gutted thermostat will probably keep it from overheating. I drove an EJ22 with a bad head gasket about 100 miles (in one long trip) with a gutted thermostat and the temp was slightly below normal operating temp. I replaced those head gaskets and it definitely blew at the bottom of the #3 cylinder from the fire ring to the coolant jacket. You could easily see it. With a normal thermostat in place it would overheat within 10 miles.

 

GD

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I'm just curiouse if there is a reason for gutting the thermostat instead of just completely removing it as I have had cars in the past where the thermostat went bad and I just pulled it and left it out the car runs a bit cooler and you normally have to block half the radiator in the winter but I would never have wasted my time trying to gut one so im just wondering if there is a specific reason for all the extra effort?

 

After paying a garage for a new radiator and diagnosis for overheating, I picked up my car which no longer was overheating. Then when going down a longer hill I noticed the temp gauge dropping way down to cold ???????? Went back to the garage and asked if they pulled and left out my thermostat. They said yes and the rest of the story is long. When we (my brother helped and did the bulk of the work, thank you Bro.) decided to do the head gaskets ourselves and when we got to the part of removing the thermostat, it was a gutted one performed by the garage to stop my car from over heating.....IMAGINE THAT :eek: If I was to do it I would do as you said, completely remove it. That's my story and I'm sticking to it.

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