Tell Me Why My Engine Caught Fire and I Have No Brakes

[DeepPower]

So I stopped my '89 SHO at the local store today and noticed smoke coming from under the hood on the passenger side. Opened the hood and saw a nice little fire, burning cheerfully in the 98°F Texas heat at the high side of the firewall, on the passenger side behind the diagnostic test connector.

So I ran to grab one of the gallons of distilled water I keep in the trunk for emergencies and poured it over the fire. I then hit it with a borrowed fire extinguisher to make sure it was gone. Carefully started the car, no power brakes. Slowly drove the car the last remaining mile home. The car is now in my garage, smelling of burned brake fluid, waiting to be towed to my mechanic tomorrow morning.

So are there brake lines at the firewall that high? What is in that area? What brake line would leak that high and CAUSE A FREAKING FIRE?? Everything is so crowded between the engine and the firewall I want to be able to give my mechanic some direction. Thanks!

 

[tery]

I don't know a lot, but I have been working for a few days here on brakes and there is a brake line that trails along the firewall going to the pass side front caliper and it begins...come from the bottom of the distribution block ..on the front end of it...that block is under the master cylinder...what makes it catch fire!!!...that's way beyond me man but I'm glad you are safe!!

 

[DeepPower]

Thanks. I'm thinking the brake fluid soaked into the firewall asbestos pad and caught fire from the engine heat in 98°F weather? Does that sound plausible?

How easy is it to get to that brake line to replace it? It has to be very cramped back there.

 

[mrecoolgar]

That is the same area that this one caught fire.
Could be a leaky rear cam cover gasket dripping oil onto the exhaust.
Or could have been electrical close to the computer.
Hopefully yours did not get this bad.
What part of TX are you in?
I'm planning to drive to Harlingen sometime semi soon.

 

[DeepPower]

That is the same area that this one caught fire.
Could be a leaky rear cam cover gasket dripping oil onto the exhaust.
Or could have been electrical close to the computer.

It's definitely fire from brake fluid.

 

[rubydist]

brake fluid is not nearly as flammable as all the oil that most of these engines have on them...

if I understand right that your brakes work but have no power boost, then most likely the fire destroyed some of the vacuum manifold that runs along the top of the firewall so that the booster has no vacuum.

 

[DeepPower]

But I do smell burning brake fluid. It's either that or power steering fluid and my PS fluid level is fine.

 

[tery]

I'm curious as to how either of them could just combust without a spark, if a drop of oil hit the exhaust manifold, it goes up in smoke ..yes..but how does that then ignite...seems like it needs a spark from somewhere

 

[Devin]

Things can combust without a spark: it is all about the flash point. The reason the oil smokes when it "burns up" is the same reason you get tons of smoke from a piece of paper before it bursts into flame. The problem is you aren't getting enough heat to rise up to the flash point where you get heat and light (ie: a flame), so you are left with a bit of heat and smoke. Once you get enough heat, flames will appear and you will get a much more efficient burn, plus a lot more damage to your underhood components.

 

[DeepPower]

This is the brake fluid I use:
ATE 706202 Original TYP 200 DOT 4 Brake Fluid
Dry boiling point of minimum 536 degrees Fahrenheit
Wet boiling point of minimum 374 degrees Fahrenheit

I got it because it has the highest boiling point of any brake fluid I could find.

 

[Devin]

Not boiling point, flash point. The flash point is higher than the boiling point. Check this out:
http://garrett-engineers.com/2005/10/what-auto-fluids-burn/

 

[DeepPower]

Not boiling point, flash point. The flash point is higher than the boiling point. Check this out:
http://garrett-engineers.com/2005/10/what-auto-fluids-burn/

Thanks, terrific reference. I admit that when I chose the brake fluid I was only thinking of boiling point. I never gave a thought to flash point.

 

[Devin]

Normally that isn't a consideration most people make, because it is supposed to sealed, pressured system. Once it is no longer sealed and pressurized it is completely useless and dangerous.

If it happens again, have someone grab the wheel and fix it yourself:

 

[tery]

Now that WAS A HOOT!! thx

I wanted to disconnect my VAPS and Fred pointed out that I would need to do that at 60 mph or else I would get the opposite effect that I was going for...So that could have been me, except I would had had to go deeper and behind the exhaust manifold...I could have made some bacon on it while I was working too!

 

[tery]

But seriously friends ...if I have a medium level? leak from the rear cam seal such that I do get some smoke from under the hood when I pull in the driveway, am I in big danger of catching fire from periodic drips onto that hot area behind the engine"??

 

[rubydist]

not likely - you will be too annoyed at the smoke and burning oil smell before you get to the point of having it actually burst into flames. unless the heat shield is missing from the cat...

 

[tery]

Thanks Fred, I didn't think it was a problem and the heat shield is there...It's Babe, the one that I installed some super heavy but still flexible aluminum foil (from the art teacher supplies)...and I made a kinda funnel shape under the cam sensor so when it drips, it trains the drip to go down the side of the block, instead of pooling under there and then dripping on the manifold or cat.. When I first put it in, it worked well..no more smoke, but my memory at the end of last summer was that it had started up a little again...I need to do that job...or actually, I wanna sell the two ATX cars, I'm definitely gravitating toward liking mTX a lot better.
Soon
T

 

[DeepPower]

I don't know a lot, but I have been working for a few days here on brakes and there is a brake line that trails along the firewall going to the pass side front caliper and it begins...come from the bottom of the distribution block ..on the front end of it...that block is under the master cylinder...what makes it catch fire!!!...that's way beyond me man but I'm glad you are safe!!

YES, that is the brake line that caused the fire, that brake line ruptured and leaked brake fluid onto the firewall insulation and onto the exhaust manifold which caught fire. My mechanic replaced the brake line.

Now there is a vacuum manifold assembly in that area (the firewall directly in front of the passenger seat) which was destroyed. Does anyone have a part number for that or know where I can get a replacement?

Is it safe to build a replacement vacuum manifold out of copper or will the copper heat up and destroy the rubber vacuum hoses?

Thanks!

 

[rubydist]

I believe that vacuum manifold is the same for all Taurus of the vintage, so a trip to the jy should net one.

 

[DeepPower]

Related problem - the brake line has been replaced but I'm still getting lots of smoke and smell of insulation at the engine firewall on the passenger side, so the firewall material must be soaked with brake fluid and oil and is still burning, or at least smoking.

It is scary to drive the car, this morning I soaked that area with water then drove the 10 minutes to my mechanic. Lots of smoke when I parked.

What are my options here? My mechanic is going to try to clean that area with engine cleaner and a high pressure hose, but what if we had to remove all that insulation? Will the cabin heat get bad? Can that insulation easily be replaced?