ABS Fuse Safety Issue (Brake Failure) !!!

[ArmArak]

So I decided to clean my coolant reservoir on my 2001. When trying to remove the bolt of the battery/reservoir holder bar, the head of the bolt snapped :ybrick:. Since I have somewhat of a rust issue the tapout did not help to extract the remaining bolt. I decided to drill it out and put a helicoil.

When drilling I accidentally went too deep and punctured the wiring harness directly underneath. :doh:. When I started the car the VSC, ABS, VSC OFF, e-brake warning lights were on. I immediately realized that something got shorted (I thought I fried the ABS ECU). Nevertheless the car started and was driveable so I decided to head home (I was only 4 miles away). About one minute into the drive a loud, continuous alarm started emitting from the dash. I still continued driving. About 200 feet before I reached home my brakes failed :wow:. I lost power to the front brakes and was relying on the rear drums only.
Luckily I made home safe.

First I was sure that I lost my entire (and very expensive) ABS/Brake unit, however after some pondering I checked the fusebox and noticed 2 blown fuses: 60 Amp ABS 1 and 40 Amp ABS 2. The latter was just a pull to remove, however removing the 60 amp fuse requires its own write-up. Long story short, you have to take apart the whole box and unbolt it from underneath.

After replacing the fuses, everything seems to be back to normal. Warning lights are off and no beep. I haven't taken the car out on the street yet, but brakes seem fine around the parking garage.

So my concern is, how can a broken fuse lead to a brake failure? Is this a design flaw? Has anyone experienced this?

 

[Dieselchessy]

Doesn't make any since to me. You can pull those fuses to disable the ABS and the brakes work fine.

Was your brake pedal very hard?

I think the ABS pump would have to somehow be in a position to block the hydraulic path to the front calipers. It would seem that blockage would result in a harder than normal pedal.

Your E-brake should have still worked fine.

You should consider buying a few set screw collars to use as depth limiters for drill bits while drilling.

 

[phattyduck]

So my concern is, how can a broken fuse lead to a brake failure? Is this a design flaw? Has anyone experienced this?

Ummmm... how is the fuse at fault? It protected your truck from burning down after you damaged the wiring harness!

I hope you fixed the harness while you were at it...

-Charlie

 

[camryn.samples]

Fuses are like a bridge in a electrical circuit I don’t know if your breaks actually failed I think they may have locked up possibly it’s hard to say.


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[ArmArak]

Doesn't make any since to me. You can pull those fuses to disable the ABS and the brakes work fine.

Was your brake pedal very hard?

I think the ABS pump would have to somehow be in a position to block the hydraulic path to the front calipers. It would seem that blockage would result in a harder than normal pedal.

Your E-brake should have still worked fine.

You should consider buying a few set screw collars to use as depth limiters for drill bits while drilling.

No the brake pedal was not hard at all. There was just nothing from the front brakes. Also the E-brake worked fine, only the dash light was on when it shouldn't have been.

 

[ArmArak]

Ummmm... how is the fuse at fault? It protected your truck from burning down after you damaged the wiring harness!

I hope you fixed the harness while you were at it...

-Charlie

I fixed the wiring harness.

Ya, the fuse really saved the truck. But I'm wondering why a broken ABS fuse caused the brake issue.

 

[phattyduck]

I fixed the wiring harness.

Ya, the fuse really saved the truck. But I'm wondering why a broken ABS fuse caused the brake issue.

The '01/'02 brake system uses an electric pump to operate/boost the brakes. You did the equivalent of using your brakes a number of times after an engine is turned off (no more vacuum boost) in a normal braking system.

So, you used up the safety reservoir of braking power, and that's when all the warning buzzers and stuff happened.

So, if that had happened during a normal drive, you would have had plenty of chance to stop the truck and pull over to a safe location. Instead, you chose to *start* driving a vehicle with 4 warning lights on the dash...

-Charlie