[Froggo]

Ford Fusion Hybrid 2010. What specifically happens?

UPDATE: Pulling both ABS fuses (Pump&Valve) completely disabled braking. Driving without ABS does not seem to be an option for Ford Fusion Hybrid 2010s.

 

[R.S.LOGAN]

Why would you want to do that ?

 

[Froggo]

Why would you want to do that ?

I happened to have the wonderful experience of total brake failure as I was pulling onto the highway at 3MPH. There was no warning that this would happen, no yellow brake lights beforehand or anything, but suddenly red brake lights went on, my car wasn't stopping as I was putting the pedal down, and the car was beeping at me. If even 1 brake was working, it would have stopped me just fine. Instead, I put my car into Park, which stopped the car, and then I pulled the E-brake to be safe. After restarting the car the problem went away. I had the car towed to a Ford dealership because I could not trust the brakes to take me the half mile to the dealership. They ran the car through the tests, checked all the brake lines and everything, ran the ABS module through their testing software, and everything came back clean. The only evidence for them that my brakes did in fact completely and totally fail was the error code they found concerning the ABS module. I am just considering myself lucky that this happened while I was going 3MPH instead of the >60MPH that I usually do.

There is a recall for Ford Fusion Hybrid 2010s with this issue -- if they were made in Mexico. My car was not made in Mexico, so I have the misfortune of potentially having to pay for the replacement of the entire ABS system unless they find out that a different issue occurred; all they are going to do is drive the car around for a while and see if the brakes act up again. I cannot pay potentially thousands of dollars for a repair that Ford should probably be recalling for, especially on a car this old.

My hope is that the brake failure was caused by the ABS pump, and that if I remove the ABS pump fuse that the ABS pump will no longer function and will no longer get in the way of my car braking without ABS. I hope to instead just drive without ABS, if indeed the ABS was the problem, and restrict myself to driving in the slow lane and just not going on the Interstate, so that I may at least drive to work and make enough money to buy a new car before this one kills me.

So that is why I am preparing an alternative to throwing money at this issue if it's an expensive one. I want to know what happens if I pull the fuse. Does it indeed just disable ABS and allow me to brake if the pump is disabled? Do I have to pull the ABS Valve fuse too, or should that be left in?

 

[R.S.LOGAN]

Different car but may answer your questions

 

[Froggo]

Thank you, that helps a lot. Does anyone know whether to take out both fuses or just the pump fuse?

 

[R.S.LOGAN]

I would take out both , could always try it that way first and see how you get on

 

[YooperDave]

Disabling the ABS shouldn't cause any problems. The only time the pump should kick in is when braking on a slippery surface, not on dry surfaces with good traction.
I noticed you said it's a hybrid...can't help but wonder if it stayed in regen. mode.
Just a thought.

 

[mrfixr55]

Disabling ABS may or may not solve your issue. ABS has several routines that will "Vote Out" the ABS. However, if there is a lot of corrosion in the brake hydraulic system (Brake fluid absorbs water and very few people have brake fluid routinely flushed and replaced), the return springs for valves that isolate a cylinder or "dump" brake pressure to a wheel cylinder may rust and the valve pop open. Lost brakes on a 91 Aerostar with Kelsey Hayes Rear Antilock brake system.

DOT3 and DOT4 brake fluid is "Hydroscopic (meaning that it absorbs water). DOT5 is synthetic. Caution: DOT5 does not mix with DOT 3 or 4!

I do not know how brakes are different on a hybrid car, if there is switching between regenerative braking vs hydraulic braking. That definitely needs to be investigated, However, if you live anywhere other than the dry southwest and have never changed the brake fluid and the car is more than 10 years old, then consider replacing the master cylinder and the ABS Valve body. If there is active switching in a Hybrid car where hydraulic braking is disabled to use regenerative braking (Boy, there has to be a fail-safe for that system), then that system needs to be investigated.

Good Luck, have a Blessed Christmas, Chanukah and Holiday Season!

 

[R.S.LOGAN]

" very few people have brake fluid routinely flushed and replaced), " This a part of routine servicing on all manufacturers schedules nowadays as per recommendations / requirements .

 

[69cj]

" very few people have brake fluid routinely flushed and replaced), " This a part of routine servicing on all manufacturers schedules nowadays as per recommendations / requirements .

Fairly simple job to do. Takes me about 1 hour and a quart of brake fluid. Every other or 3 years max. You can definitely see the difference when the new fluid starts to enter the drain bottle.

 

[Froggo]

Thank you. I'm pretty sure the dealership checked the brake fluid when they did their diagnostics on it, but I never thought to consider an error happening with the regen braking. That's spooky. But, just about every "Brake Failure Ford Fusion Hybrid 2010" search result that matches what happened to me has to do with the ABS pump failing, so that's still where my suspicions are. Now I just have to figure out how to actually get the fuses out -- they're flush with the fuse box (this car totally just hates me)

UPDATE: Pulling both ABS fuses (Pump&Valve) completely disabled braking. Driving without ABS does not seem to be an option for Ford Fusion Hybrid 2010s.