Replacing Front Brake Pads
 

It looks like I'll need to replace my front pads on my 2007 FEH before winter. Two questions:

1) When I disconnect the battery, which is necessary, do I need to use a keep-alive 9 volt battery plugged in to the cigarette lighter to keep from messing up other functions?

2) What kind of pads should I get, if I don't get original Ford parts? i. e. Ceramic or non ceramic pads?

Thanks.

Re: Replacing Front Brake Pads
 

Have a look at this thread to see if it helps you out.

https://www.greenhybrid.com/discuss/...-dealer-24568/

Not sure about ceramic or non ceramic pads, but considering that the pads last a long time (regenerative braking) I'd stick with Ford parts. IMO.

Re: Replacing Front Brake Pads
 

Thanks for the link, but it didn't answer my questions.

The shop manual says to disconnect the battery and pull the two fuses. I'm wondering if I need to keep the memory alive to avoid other computer related issues.

Also do we know the original pads are not ceramic?

Thanks.

Re: Replacing Front Brake Pads
 

Tom, make sure you lift the hood and let the FEH sit for ~12 minutes so the PCM can properly shutdown all the relays. If those relays are not properly shutdown by the PCM, current can flow from the HV battery through the DC/DC converter draining your HV battery. Some here have reported the HV battery drained down after they disconnected the battery ground to work on their radio. You can also just disconnect the HV battery plug on the battery. Don't worry about KAM, it will reset to the default setting and relearn from there.

Don't know if the pads are ceramic.

GaryG

Re: Replacing Front Brake Pads
 

Thanks. So you let it set the ~12 minutes before you disconnect the 12 volt battery?

Got it. I didn't see this in the shop manual, but I may not have looked far enough.

Re: Replacing Front Brake Pads
 

You know when you turn the Key Off the radio will play for ten minutes or until you open the door? Same thing happens with steering (3 seconds), fans, brake pressurization and other hybrid systems like the TCM and TBCM. The 12 minutes is just to make sure the PCM shuts down everything. If you disconnect the ground to the battery the PCM uses that ground to ground the relays to disconnect power through them. This is in the PCM/ED manual under Hybrid Electronic Control Software Section "Normal Power Down Sequence". The 12 minutes and raising the hood is just my idea because I know the light will turn Off automatically by then.

In most cases the techs don't bother because they make the repair fast. Doing a brake or other time consuming job can get long when you don't have a parts dept a few steps away. I just don't like wasting any SoC myself. Taking out the fuses is a back-up so the brakes don't pressurize under any conditions.

I think it was BillyK stating his HV battery drained after he disconnected his 12V battery. My answer was the PCM didn't do a proper shutdown. Another poster was disconnecting the PCM ground wire at night and had the same problem.

GaryG

Re: Replacing Front Brake Pads
 

Adding a little insight from semi-related experience: My 2006 F-350 work truck takes 30 minutes for everything to power down. I was having dead battery issues and assisted the mechanic diagnose the problem. His meter monitored the drain on the battery (amps), and we watched as the truck's electrical components shut down. Several systems shut down in the first 10 minutes or so, but one or two stayed energized 'til the 30 minute mark.

When it comes time for me to replace my brake pads, I intend to just follow the owners manual re: putting the vehicle in brake 'service mode'. Am I missing something?

Re: Replacing Front Brake Pads
 

I don't have a FSM and mine is an '06, but the owner's doesn't say anything about disconnecting the battery when doing brake work. It just says to put it into service mode which will prevent the system from pressurizing while it's in that mode. I'm coming due time to replace the fronts and that's all I'm planning on doing.

Re: Replacing Front Brake Pads
 

You may be reading something about the standard Gas version Escape without an electrical fluid pump. If the system pressurizes while working on the FEH/MMH brake system you could blow corrosive brake fluid everywhere and hurt yourself and FEH/MMH systems. Under the Hybrid BRAKE PADS Removal and Installation Section 206-04-3 of the '05 FEH Workshop Manual #2 clearly says disconnect the battery and remove the battery junction box fuses 24 (50A) and 31 (50A).

GaryG

Re: Replacing Front Brake Pads
 

Good luck with that.

Here (attached) is what Gary is talking about ......but from an '06 FSM.

Re: Replacing Front Brake Pads
 

Okay, may be my FEH 2005 different but I did front brake's pads examination by removing them when right front wheel bearing changing, no battery was disconnected or fuse removed. Key was in position to allowing steering wheel to be rotated. So why system was not pressurized?

Re: Replacing Front Brake Pads
 

Ok, here is what it says verbatum in my '06 Mercury Mariner HYBRID (can't believe you'd actually think I was so stupid as to not consider that) manual.

Pg. 295

"Brake pad replacement information

The Regenerative Braking System checks the integrity of the brake system at times when the vehicle is parked. This is done by developing brake pressure for short periods of time. In order to change the brake pads, it is necessary to enter the Pad Service Mode. This will prevent brake pressure from being applied.

To enter the Pad Service Mode, perform the following with the vehicle stationary:
1. Place the vehicle in Park and turn the ignition to the ON position.
2. Apply the brake pedal.
3. Turn the ignition OFF, then ON three times and then release the brake pedal. The total time elapsed for the three ignition cycles and brake release must be less than 3 seconds.

The brake warning lamp will:
- flash as stored hydraulic pressure is released.
- remain illuminated once the pressure is completely released.
- flash if the brake is applied.

To exit the Pad Service Mode:

1. Apply the brake pedal and turn the ignition OFF then ON. This will cause brake pressure to be developed within the brake system. Once the brake pressure is developed, the brake warning light will turn off.
2. The Pad Service Mode will also be exited if the gear shift leer is moved from the (P) Park position, the vehicle is moved (wheels rotate) or the ignition is turned OFF.

NOTE: The brake system on this vehicle can only be bled at a authorize dealer."


Ok, now that's straight from the: "Mercury Mariner Hybrid Owner's Guide"

Re: Replacing Front Brake Pads
 

All that said, when I did the rear brakes, I placed a screw driver handle between the brake pads while I dressed the brake disk just in case so it wouldn't blow out the piston should I have screwed something up and the system pressurized anyway.

Re: Replacing Front Brake Pads
 

FWIW, this same information exist in the 2008 FEH/MMH owners guide as well on Page 283.

Re: Replacing Front Brake Pads
 

It should be in all the FEH/MMH Owners Manuals because it's in mine also. I didn't think to look for brake pad replacement there and certainly don't expect the dealers would follow that procedure if it's not in the Workshop Manual. It may be that because of liability the dealer remove the calipers to inspect and change the seals or may have to replace the calipers which would call for bleeding and replacing the brake fluid.

The other thing that concerns me is leaving the Key in the On position for long periods of time. Normally with the key On the HV battery continues to drain into the 12V system. If it was a matter of quickly changing just the pads without turning the rotors I guess that would be the way to go. I've never had a good experience going that route myself because of the rotors always have groves which cause more brake problems after the pad change. For that reason I would spend the extra money and just replace the rotors with new ones and address the calipers when and if they go bad.

GaryG

Re: Replacing Front Brake Pads
 

Wouldn't waiting the 12 minutes then pulling fuses 24(50A) and 31(50A) located in battery junction box suffice in servicing the brakes?. I wouldn't think I would want to leave the key in the ignition period that's breaking one of the most important safety rules there is!!

Re: Replacing Front Brake Pads
 

I guess you can be as cautious as you feel necessary. I didn't feel it was necessary to do anything more than just do the service mode procedure. I changed the pads before they were completely worn. Sure the rotors weren't compltely smooth, but they were in plenty good enough shape to me. Just as a precaution, I always hit them with some sand paper to knock the gloss off of them. I believe it helps the new pads seat against the less than perfectly smooth rotors. Still, doesn't take all that long. I didn't worry about running down the 12V battery. I was sure to turn off any other power drain such as radio or climate control fan. Made sure doors were closed so no interior lights were on either.

Re: Replacing Front Brake Pads
 

I agree, I want all power Off and that includes pulling the orange plug on the HV battery. I want the SoC levels in the 12V and HV battery the same as when I started the Job myself. If I run into trouble and need to change other parts, I know I have time to order and get them while the batteries are sleeping. The real fact is I always stop with regen braking and driving without brakes (DWB) and expect my original brake pads and drums to last as long as I own the FEHs. I will also know right away if I have rust or anything causing any wheel drag because of the way I monitor mileage and neutral coasting.

GaryG

Re: Replacing Front Brake Pads
 

It would be interesting to know if the service mode procedure ending with the Key ON shuts power from the HV battery and other 12V systems. For instance, normally with the Key ON 12V power is supplied to the TBCM, TCM and the electronic coolant pump (MECP) etc. To test if the MECP is working properly, you normally turn the Key ON and feel the pump with the engine Off. This should be easy to check but what about the other systems?

GaryG

Re: Replacing Front Brake Pads
 

I have enjoyed my 2006 FEH and have 60k miles. I've followed all recommended maintenance etc. Two weeks ago the brake warning light started coming on occasionally. I checked the emergency brake..no problem, the car would brake as it normally would, I checked the brake fluid levels..no problem..but the light and alarm would still come on especially when hitting a bump or turning. I thought maybe a sensor and electric problem with the dash. Took it to the dealer who said they couldn't get the light to come on when they drove it..I explained I wasn't imagining it. They took down more info..I became wary of if they knew what they were doing. I was in shock ( to say it mildly) when they said they hooked it up to a diagnostic machine and what I needed was a new master cylinder ($1800.) If the brake light still continued "Ford" recommended a new ABS system ($4500.) Even after they would do this work they couldn't "guarantee" the problem would be solved. I asked why there wouldn't be some other physical evidence that the brakes were bad, ie fluid leak, squeaking, spongy breaks..and was told they didn't know but they had to advise me that this was the "repair" that Ford recommended. I haven't done anything as I want to get a 2nd opinion. After reading what alot of you have said I'm really stumped! Any advice? I too am afraid to drive it!

I've made copy of this from Ford Escape Hybrid Maintenance & Repair forum, hope nobody have had same problem here.

Re: Replacing Front Brake Pads
 

I wonder if the service department at this dealership is telling the truth and just ripping you off. If you have a paper document of this "estimate", I would contact Ford Motor Company customer service on this excessive estimate.

Re: Replacing Front Brake Pads
 

I'd look for another dealer with a better mechanic before I'd just lay down $6000+ on what is probably a hunch. It could be something very simple like a poor connection or ground.

Re: Replacing Front Brake Pads
 

Thanks to Peelman for 24(50A) and 31(50A) located in battery junction box; I tried and tried to get Pad service mode to work, but to no avail. (2006 MMH). Rear pads; drivers side, even wear, about half way done. passenger side outer pad done, just starting to touch metal in one corner, the other pad close to full. If these had worn evenly, I would not have done the pads at 94K miles.

Re: Replacing Front Brake Pads
 

2009 Ford Escape Hybrid (front disc, rear drum, 2WD)
I tried every combination of key position, number ON/OFF cycles, brake pressing and unpressing and still could not get it into 'pad service mode' or 'safe brake service mode'. I also did not pull any fuses or disconnect any battery terminals, but I got the pads replaced. The fuse terminals I've read to pull correspond to the horn relay and transmission module? How that stops the brakes from testing I have no clue.
I simply changed them like every other car I've ever done. I just had the car in park and the key off and out.
I took my time and had the calipers removed for at least an hour each.
The braking system never tested itself nor actuated. The piston stayed put.
Maybe this is a difference with the 2009 and up models. I have no idea why any automotive engineer would want to 'test' the brake system at 5-10 min intervals while the car is off and in park...

Re: Replacing Front Brake Pads
 

Pull the fuses... it's easy. If the system cycles while the caliper is off the disc you're going to push the pads & pistons out and brake fluid everywhere...

Pulling the fuses removes power from the circuits that would power the system cycling. Thus it won't cycle. BTW if your hand were in the wrong place when the cycling happened you could be injured... pull the fuses.