News

Help! F355 Brake Warning Light after installing new brake pads

Discussion in 'Technical Q&A' started by AZLambo, Dec 31, 2005.

  1. AZLambo

    AZLambo Formula Junior

    Nov 4, 2003
    506
    Phoenix, AZ
    Full Name:
    Jeff
    #1 AZLambo, Dec 31, 2005
    Last edited by a moderator: Sep 7, 2017
    Well, good news and bad news. First of all, thanks to Ricambi America for my new Porterfield R4S brake pads, and getting them to me so quickly. I had 17,000 miles on my 1995 F355 and could not put up with the squeeking brakes any more. As it turned out, my pads still had probably 70% of the pad left, but let me tell you..........the Factory Pads had a "backing pad" on the metal part of the pad (I am guessing to control squeeking), BUT the backing pad was only 3/4 of the length of the pad, and therefore, one of the two pistons was hitting where this backing pad ended..........half of the piston on the backing pad and half on the metal part of the pad itself.......causing an uneven condition, which I think was causing the squeeking! (See the Photo)
    I installed the new Porterfield R4S pads in my 1995 F355, with the help of this great instructional post by Daniel (Jack Russell Racing):

    http://www.ferrarichat.com/forum/showthread.php?t=25468&highlight=brake+pads

    Anyway, this was my first attempt at brake pad changing.......actually really easy. Some things I would suggest:
    1. Push in the pistons with the old pads still in place, using a vise grip and a rag to keep from marring the caliper.
    2. Definitely use some spray on "anti brake squeal" on the backing of the pads.

    Anyway, another thing I found out is that the front inner brake pads, that have the "wear sensor".......on the F355, the sensor wire is embedded directly into the pad material, in the edge of it, near the backing plate,..not in a little plastic piece that fits into the "U" channel in the middle of the pad, like the 348. I cut off the wire where it entered the pad, stripped some insulation back, drilled a hole in the new pad, in the same location, and epoxied in the wire. There is enough extra length in this sensor wire that losing a half inch isn't a problem.

    Anyway,........good news...NO MORE BRAKE SQUEEKING!!!!!!!
    Bad news.....my brake light is on and won't go off. I drove around the neighborhood and the braking seems fine. I made sure that the brake fluid level never got down below where it should. Now......when I was doing the first wheel...back right.......the outer bleed screw bled correctly....after about a quarter turn. The inner bleed screw woundn't let any brake fluid out....and I turned it open a lot.................so I went on to the next wheel. This time, no brake fluid out of either bleed screw! Am I doing something wrong????? Anyway, I continued, just replacing the pads.

    Can anyone tell me how to correct the problem, and get the brake light from lighting up? Did I somehow get air into the brake lines?

    Thanks,
    Jeff
    Image Unavailable, Please Login
    Image Unavailable, Please Login
    Image Unavailable, Please Login
     
  2. To remove this ad click here.

  3. Merdav

    Merdav Formula Junior

    Apr 11, 2004
    971
    My Portefields were great for the first 100 or so miles than started squealing also. I changed them out already but same result. Now I grinded a small bit off the leading edge of the fronts...still sqeal, next I'm going to try and have the rotors cut, hope you make out better.
     
  4. ernie

    ernie Two Time F1 World Champ
    Lifetime Rossa Owner

    Nov 19, 2001
    22,063
    The Brickyard
    Full Name:
    The Bad Guy
    I'm gonna guess this little manuver is the cause of the break light.
    Maybe.

    Did you have another person in the car pushing on break pedal while you opened the bleed screw? If not, then there was no pressure to properly get the air out of the lines. If the above is the case, then you need to repeat the break bleed with another person.

    This could also be the reason for your light.

    Last, ATA BOY!!!! Real men work on their own cars.:D
     
  5. AZLambo

    AZLambo Formula Junior

    Nov 4, 2003
    506
    Phoenix, AZ
    Full Name:
    Jeff
    Yes, I had my son pushing the brake pedal while I "cracked open" the bleed screw.

    I have been doing some further reading. There is some discussion about having to have the ignition key on when bleeding on a 355 because of the
    ABS system. Here is a quote from an F355 service manual I have on CD:

    Brake Bleeding: Do from brake calipers as in a conventional braking system.
    This must be carried out with accumulator charged and pump
    supply on.

    What does this mean? Do I need the ignition key on? Is this why I wasn't getting anything out of the bleed screws after the first one?
     
  6. AZLambo

    AZLambo Formula Junior

    Nov 4, 2003
    506
    Phoenix, AZ
    Full Name:
    Jeff
    The "wear sensor" thing I did would have turned on the "Parking Brake" warning light if I did anything wrong there. (Which I didn't). Once the pad wears down to the wire, it completes the circuit when the wire makes contact with the rotor. Again, the manual says that this will trigger the "Parking Brake" light, not the Brake warning light...which is what is lighting.

    I have a feeling that I need to re-bleed the system with the ignition on.

    What do you think?
     
  7. To remove this ad click here.

  8. No Doubt

    No Doubt Six Time F1 World Champ
    Consultant

    May 21, 2005
    67,323
    Vegas+Alabama
    Full Name:
    Mr. Sideways
  9. ernie

    ernie Two Time F1 World Champ
    Lifetime Rossa Owner

    Nov 19, 2001
    22,063
    The Brickyard
    Full Name:
    The Bad Guy
    Yes.

    If the pump has no power going to it, it can'nt pump. So the first push on the pedal released the stored pressure that was in the system. Since the pump wasn't on it repressurize the system, that is why you didn't get any pressure on the other screws.

    So yeah, rebleed it with the key on.
     
  10. fatbillybob

    fatbillybob Two Time F1 World Champ
    Consultant Owner

    Aug 10, 2002
    20,350
    socal
    Bleed with key on engine off so the abs pump cycles when needed. Bleed 2 man style and stop when pump comes on. The pump stops you continue bleeding that same wheel until you have clean no air fluid. Is the warning light a brake like or ABS brake lite? ABS= 1) try checking to see if you accidentally disconnected the ABS sensor to the caliper area or to the ABS ecu itself under the carpet by the master cylinder. 2) bleed system properly as described above.

    normal brake light = bad connection of your warning sensor. R4 are race pads and have more metal and if they contact your rotor because of bad retraction of your piston in caliper it may set off the light. I do not know about the R4s street pad. R4 can squeek more than OEM pads. Also, you may have disconnected a bad spade terminal of the wear indicator at the caliper level. I.E. where the wear indicator wire conects to the caliper. Also check that your parking brake crappy switch is actually turning off when you put the park brake handle down. Try banging that a few times too.
     
  11. AZLambo

    AZLambo Formula Junior

    Nov 4, 2003
    506
    Phoenix, AZ
    Full Name:
    Jeff
    Well, here are my thoughts at this point:

    1. The parking brake warning light isn't on. The parking brake light works fine with the parking brake engaged, and goes off when not engaged. The manual says that this parking brake light will turn on if the wear sensors are activated. I connected the wear sensor wires back up to their connections at the caliper after I emedded the other ends in the pads. So no problem with that system.

    2. The ABS light is not on. The ABS pump is working fine. No problem there.

    3. The Brake warning light is the one that is on. (see the photo shown in my original post).

    I am going to re-bleed the system with the ignition switch on, so that the ABS pump can keep re-pressurizing the system. I feel that that is the reason I only got fluid out of the first bleeder screw I tried......and none out of the others.

    I'll let you know the results. Thanks.
     
  12. To remove this ad click here.

  13. AZLambo

    AZLambo Formula Junior

    Nov 4, 2003
    506
    Phoenix, AZ
    Full Name:
    Jeff
    I re-bled the brakes, with the ignition key on, so the ABS pump could keep cycling and so there was enough pressure in the system to bleed the brakes.
    If you do not have the key on, no amount of pumping the brake pedal will get brake fluid to come out of the bleed screws after the pressure has been released on the first bleed screw. (You find out so many things about your car when you do it yourself!) Anyway, my BRAKE WARNING light was still on after all this! I didn't think that the wear sensors could be the problem, since the owner's manual says that if the wear sensors activate, the PARKING BRAKE warning light would be the light that comes on, not the BRAKE WARNING light. Well, thanks to a suggestion by someone, I checked the wear sensors. I shorted one out against the rotor, as is what would happen if the brake pad wore down to that point. Guess what?........the PARKING BRAKE warning light DID NOT light up! Those bastards that wrote the owner's manual were wrong!!!!!! Anyway, when I pulled the wire away from the rotor, the BRAKE WARNING light went off!!!!!!!!!! WOO HOOOOOO
    I didn't screw up bleeding the brakes and installing new pads! One of my wear sensors that I drilled a hole for in the brake pad material had shorted out against the backing plate of the pad (I drilled a little too close to the backing plate) and had caused the BRAKE WARNING light to light up!

    Anyway.......all is well. No BRAKE WARNING light, no squeeking brakes with my new Porterfield RS-4 pads. (I used the anti-squeek spray-on stuff).

    Now, I have yanked off the sensor wires. I guess I can just check the pads every so often for wear. Anyone know of a sensor that will fit the Porterfield RS-4 Pads? Daniel, at Jack Russell Racing, (Ricambi America) tried one sensor and it did not fit.

    If not, I'll just leave the sensors off.

    Thanks,
    Jeff
     

Share This Page