first nice day, disaster.

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72HCODE

"My World is Fire and Blood"
Joined
Jul 4, 2010
Messages
3,091
Reaction score
56
Location
New York
My Car
71 Mach 1.
well its been about a year since i last drove my car. so first nice day out i figure i'd take a spin.

first thing i did was inspect the car looking for obvious issues. i looked under and over the chassis and engine bay, checked for brake leaks.

the usual converter leak was there still weeping. popped the master cylinder cap to have a look, was full and looked ok. inspected the engine compartment for rodent damage, battery has been on the minder so it was ok. checked fluid levels all good.

when i stepped on the brake pedal something was a little off but it has been a year since i drove it. i pumped the pedal and it seemed to hold pressure.

so did the prestart to get some oil up to the topside of the engine, set the curb idle and she turned right over sounded good.

did a forward and back test on the trans and then filled up the tires with air as they were a slightly low.

so hoped in the car. I did a brake test to just make sure i was ok and i locked up the tires. so with 1/2 tank of gas i left and listened to some tunes. 

Everything was fine for an hour.

Then 1 hour into my trip i was making a left turn and suddenly the brake pedal went right to the floor and i felt a big pop from the firewall right through my shoes.

and a sudden loss of brakes. Well i still had brakes all the way on the floor. just great the master cylinder took a dump and i had a feeling something was wrong when i started the inspection.

after filling my pants i limped home. getting out into the garage i smelled something like burning brakes that turned out to be something in the right rear drum, maybe its dragging i have no idea but the entire rear tire cavity was letting off tremendous heat. there was no fluid leaking that i could see outside of the drum.

to the front to inspect the master. i popped the cap and she was still full at the same level as when i first looked.

the weep on the booster was dry so i assume some kind of internal seal failure.

so now i have another master cylinder to install and to jack the car up and look at the wheel cylinders.

all i wanted to do was drive on a nice day.

 
Went with my t-bird to yearly tech control 2 years ago, and as part of that, they tried the parking brakes (which I never use). No prob passed the test. but when I got home and stepped out, I smelt the car was about to melt/burn down. Lots of heat, cooled it off with a bucket of water in a rush. Making a huge cloud of steam and it took very long before it was completely cold. I was scared as hell :) The hand break lever corroded did not return completely and so I was driving with the rear breaks on. I did not noticed any slowdown while driving. In the end I had to replaced the jaws and most of the breaks parts.

I can only imagine the feeling when you realize the break pedal has gone down to floor while driving. You are very lucky nothing has happened.

 
Well, if yesterday was your nice day that was Friday the 13th you know!!


 
no was the 14th.

amazingly the failure happened just at the right time, no traffic no large hills.

the pedal was to the floor but the car was still stopping of course when it happened i reduced speed to 20-30 mph. which i'm sure started to anger the cars building behind me.

but i was able to get home in one piece.

now this is the same master where i had switched from dot 5 to dot 4 because of all the leaks i was getting with silicone fluid and not swelling the O-rings correctly.

i flushed the system a few times over the years since that change but it is more then possible the damage was done. I've been through like 4 masters in 13 years which sucks.

now the really sucky part is going to be sucking the old fluid out, taking everything apart swapping the master again and inspecting the front and rear wheel cylinders and see what is going on. i will check the braking brake i never did check that stupider things have happened.

i think whatever is dragging my right rear brake saved me today because it was obviously helping to slow the car down. but i think the main failure was on the firewall :(

 
Saturday the 14th is usually one worse than Friday the 13th!  :D 

A little story....:

About 15 years ago I changed the Master cylinder and must have had some air trapped in it. Brakes worked for 3 full days until suddelny the pedal went to the floor and I had no brakes whatsoever. I learned that day that "emergency Brake" is a term that the parking brake does not deserve as it only loked the rears while car didn't slow down the tiniest bit.

I was just going into a roundabout with a van in front of me which had stopped. It moved just fast enough for me to squeeze past it on the right, turn left into the roundabout, take the first exit, get into a spin and end up backwards on the sidewalk 2 cm away from a concrete wall. On my way there I had avoided at least three cars and two road signs by mere inches. 

I only have about 10 gray hairs but all of them must have come from that particular day. (Ok, one or two may be because of 18 years of marriage). I aged ten years in ten seconds. I still don't know why I didn't hit anything as there were enough obstacles everywhere. 

Long story short: Brakes are THE most important thing on a car, forget about horse power, torque etc. Brakes can make or break you!

You were pretty lucky it turned out that way! I'm glad for you!

 
Sorry for your bad luck 72Hcode. I had brakes fail on my 96 F250. Luckily I was still on my driveway. I ended up changing all brake lines and the master. Glad no one got hurt. There will be better days coming up.

1goldcjmach

 
been a few months finally jacked up the piece of junk to get the wheels off because i need to rebleed all 4 calipers and wheel cylinders when changing the master.

got the new master and bench bleed kit, got a new vacuum bleeder as well. now after the brake failure i noted that the right rear tire was putting out a lot of heat after i limped home and parked.

so the first thing i did before touching the master was pull the right rear drum

and...

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the glue used for the shoe lining completely failed.

that would explain the sudden loss of brake power i felt

i checked the drivers side and the shoes were perfect... GREAT so i ordered new 10x2" rear drum shoes RIVITED instead of glue!.

i will start with replacing the drum hardware then rebleed the system and see how the master is doing then.

 
Finally got the car back on the road. parts were back ordered.

I was suspecting more damage but the prop valve and the master cylinder appear to be ok. the drum shoe failing appears to have been the only problem.

i rebuilt both rear drums, flushed the entire system with new dot 3 fluid and bled the system, master was pumping correctly and holding pressure. nothing appeared to be leaking as i inspected the rear wheel cylinders. so went for a test drive. did some moderate stops to heat up the shoes all seems ok again.

 
The purpose of the dual master cylinder and proportioning valve/warning light switch is to prevent complete loss of braking if one brake fails. Even though you lost the rear brake the front brakes should have still been functional and the brake warning light should have been on. I would do a Fantomworks style brake check, make sure all four brakes leave tires marks during a "panic" braking.

 
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