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A question for the mechanically (cars) inclined

polycounter lvl 18
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Cthogua polycounter lvl 18
So I have a Subaru Forester and for the last 3 weeks the rear passenger side brake had been making a really nasty grinding noise everyime I would go to brake. Now from previous experience I had a good idea what that might be and that the brakes were going to need to be done, and the rotor was probably going to have to be replaced on that side. Unfortuantly I wasn't going to have the money to do that untill the 15th of this month. So the 15th rolls around and I'm thinking about making an appointment at a shop to get the car fixed when on the way home that night the pressure drops completely out of my brakes and I have to drive the rest of the 10 or so miles home with no brakes....scary. I took it to the shop the next day and they tell me that the caliper itself had been grinding against the rotor and had actually been essentially ground apart, the piston popped out of the line and the brake system lost pressure. Anyway I figured something like that was going on and figured I was going to have to replace atleast the rotor and maybe the caliper as well. However the guy wanted to do both sides, even though there was really nothing wrong with the drivers side, execept that it maybe needed new pads. Now I didn't have the kind of money they wanted for that so I just had them do the one side. When I get home and look at the reciept under technicians comments it said "Customer requested only one caliper and one rotor, vehicle is not safe. Will have hydrolic (thats right he misspelled it) failure soon" So today I called them up seeking an explaination as to why I was going to have hydraulic failure soon and he said that having one brake done was like the worst thing I could've done and that it probably would've been safer for me to park the car till I had more money to fix it. He said that since one side was new it had more tension or something so it threw off the rest of the brakes, and so I needed to replace the caliper and possibly the rotor on that other side to even it out.

Now I've repeated that last bit to a couple of people, even some that knew a fair amount about cars (my dad)and the response has been basically that it's bullshit. That the brake system is hydraulic and that an equal amount of pressure is going out to all the brakes , new or not as long as there's no leaks. A couple of people had said that having all the pads replaced probably isn't a bad idea, but replacing the caliper seems unnessecary. Anyway, I was hoping someone with some acutal mechanic experience or knowledge could comment on whether or not this is real, or this guy's just trying to get me to spend more money.

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  • notman
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    notman polycounter lvl 18
    Well, I work for TRW Automotive's brake division, and not that I claim to be an expert, but I do know about brakes.

    First, you are correct about your suspicions... it is completely safe. Typically it is recommended to replace both sides at the same time whenever one side fails, if the failure is related to seal damage. Basically, if it wore out on one side, it's likely to wear out on the other side shortly. Since yours was due to improper maintenance, it shouldn't be necessary to replace the other side.

    The rotor probably should be replaced on the other side if it's considerably older than the other side. The pads should always be replaced on both sides at the same time, but it's not necessary to do fronts and rears at the same time (usually fronts wear out twice as fast as the rears). The reason you always replace the all the pads on one axle is that they tend to wear out at the same rate. If you did say the right side and not the left, then in your case, you're probably starting to damage the left side also.

    Otherwise, if you only replace brakes and rotors on one side, you will have a difference in pressure, but the only thing that is likely to result is more aggressive braking on one side (the new one).

    Crooks like that are the reason I prefer to do all my car maintenance myself. I use to work with a bunch of old service techs at GM and they would share stories all the time of how shops they were in would over emphasize maintenance repairs so they could talk the customer into more repairs.
  • Jay Evans
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    Jay Evans polycounter lvl 18
    I can't see why you would need a new caliper on your non-damaged brake. Replacing brake pads symmetrically does make sense though. Another thing is you shouldn't lose "all" brakes unless your master cylinder is gone. Your car is set up so that if your left rear loses pressure so will your front right, and vice versa. That's my understanding anyway. The weird thing is that your brakes should wear close to symmetrically, so if you had this huge wear related failure on one side it would make sense the other side should also be looked at. Who knows though, so many of those dudes are scam artists, and others know load more about brakes than any of us:P
  • sir-knight
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    sir-knight polycounter lvl 10
    seized slider pins on the failed caliper were probably the cause of the caliper being locked like that...

    I would have the other 3 corners inspected and serviced... servicing is not difficult, just get the corner of the car up in the air, take the wheel off...

    do the top of the caliper (unbolt it), pull the pin out, clean it with brake cleaner, dry it off, regrease with a synthetic brake grease, reassemble, do the other pin on the bottom of the caliper... put you wheel back on, move to the next corner.

    You can also check the wear of your pads yourself as they just pop out as soon as you pull out the pin and rotate the caliper out of the way.
    http://www.scoobymods.com/forums/showthread.php?t=8376&highlight=brake+service
    This is a rear caliper for a 96 subaru, it should be fairly similar. Go to a local autoparts store and ask for copper antiseize, synthetic brake slider pin grease, brake cleaner. They may even have the instructions if you ask.

    You don't need to replace your other rear caliper, but I would definitely make sure all the other slider pins are functioning properly. So you don't get a repeat.

    The brakes should be serviced once a year in this fashion, it took me about an hour and a half, and I've never done work before :P Btw, what year is your forester? I have an 07 impreza. It might help if you plugged yourself into a few of the subaru community sites and ask for help on the subject. Nasioc.com being the main one, a forester is basically an impreza anyways in mechanics, so you'll find lots of help there.

    You can save yourself a lot of money by doing simple service yourself and avoid catastrophic failures like a caliper grinding down to nothing and loss of brake pressure :P

    edit:

    oh yeah, on the diagram, you want the remove the bolts T3, those are the slider pins, be careful of the rubber boots on them, don't tear them but they should pull off the pin, spray those down with cleaner too to get any grime that made it in there, out.
  • sir-knight
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    sir-knight polycounter lvl 10
    also should grease these spots marked here with the brake pads with the grease

    http://forums.nasioc.com/forums/showthread.php?s=&threadid=409262


    once I get home I'll post the pdf of the front caliper as well wink.gif then you can get to having some fun on your car. Also if your brakes haven't been serviced in a while, get the liquid wrench or wd40 our on those T3 bolts... you don't want one to snap on you, but it should only take about 20-30 pounds of force to get one off.


    edit

    http://dreamers-ink.ca/car/frontdisk.jpg

    again, T3 is the pair you want to remove, 4 is the little rubber boot and 3 is the slider pin itself.

    Now with the caliper off, the piston might contract a little so when you put it back on it could be tighter than it started, if you got strong hands you can squeeze them back into the caliper.

    Once all 4 corners are done, everything is tightened back up, just go for a slow drive around the block in a quiet street. When you start up the car, push the pedal all the way down to move the pistons back where they should be... you don't want to be on the street, needing the brakes and you need 2-3 pumps to put the pads in contact with the rotor again :P
  • tokidokizenzen
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    tokidokizenzen polycounter lvl 17
    Unless a caliper is leaking like the one you replaced, you should never have to replace one otherwise. Notman is right about replacing rotors and pads on the same axle. If one side is worn then the other side will be too.

    I understand your frustration with the mechanic but when all is said and done you are to blame for the brake failure. Also, driving your car without brakes is just stupid. You not only put yourself in danger, you put those around you too. Oh and something else you maybe didn't consider; I'm guessing you drove using your parking brake instead? That is one of the worst things you can do. Not only is it totally unsafe but extremely bad the life of your P brake. It's not made for the extreme heat. And, replacing a p brake is not cheap at all.
    end rant.
  • Toomas
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    Toomas polycounter lvl 18
    The mechanic is propably just keeping his ass safe and he has every right to do so. Im not sure what Subarus repair procedure is for failed caliper but im sure it includes atleast rotors and pads on both sides.

    If you still think you are getting scammed, call your local Subaru dealer and tell them you have a problem like you had and ask for quote for fixing it.
  • Cthogua
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    Cthogua polycounter lvl 18
    Thanks for the advice everyone smile.gif Also not lending to this particular mechanics credibility, I came to figure out as I searched the internet for information on this subject that I was overcharged for the part by about 150% However in that search I managed to find a more trustworthy mechanic....but I'm also beginning to think I should really just learn to do some of this by my self.


    ...and it wouldn't be a polycount thread without someone bringing blame to the table. The parking brake was a last minute attempt to slow down when I went to step on what I assumed was going to be working brakes. If I had an idea something like that was going to happen I wouldn't have been driving the car. confused.gif
  • sir-knight
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    sir-knight polycounter lvl 10
    yeah you don't want to use the parking brake to stop too much in a subaru, that will fuck your center differential pretty quick with continued use.
  • Cthogua
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    Cthogua polycounter lvl 18
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