Brakes Dont Work As Good After Brake Job

[2013 Geee T]

I had my front brakes done and afterwards they felt soft and less responsive. My mechanic friend did them for me and turned the rotors and I used Ford parts. The clips were not right though for some reason so we used the old ones.

He assumed some air got in the lines so he bled the brakes and changed the fluid as well. They are better but don't feel as good as they used to. I did notice after I slammed on my brakes to avoid someone almost hitting me that they felt a little better after though.

Any ideas what would cause this?

 

[Rusty67]

Depending on the type of pads you got they may need to be bedded in. The fact that they work better after you got them hot leads me to believe that yours need that. Do a couple/5 hard stops in a location where no one is around and see if the braking performance improves.

 

[2013 Geee T]

I was thinking that but never had to do that before. They are just Motorcraft pads from the dealer. The rotors are Brembos though but this is the second set of Ford pads to go on them.

I also get worried that doing some hard stops will warp the rotors again! The Brembos don't seem to warp as easily as the Ford rotors but they still managed to do it.

 

[Rusty67]

Every time you turn your rotors, you take material off of them which lowers their ability to deal with heat. I never turn rotors more then twice. Did your friend make sure to check their minimum thickness before turning them ? Just bedding the pads in shouldn't warp the rotors unless they are in really bad shape.

 

[sneaky98gt]

Bleed the master cylinder as well. I'll bet that's what your problem is.

 

[trinity_gt]

If you guys didn't touch the hydraulic hoses or bleeder screws there should have been no more air in the lines after the job than before. Unfortunately, by bleeding and flushing you've added a new variable here.

I agree with Rusty67: It's probably the pads needing to be bedded into the rotors. Because the face of the pads are not a perfect "mirror" image of the rotors when new there will be only partial contact between the two at first. You need to run them in for a bit to get all the friction and pedal feel back.

Hopefully in the process of bleeding/flushing you didn't inadvertently add air to the lines.

 

[nine2oneGT]

+1 on seating the pads with 5-8 very hard stops from about 50 mph.

 

[2013 Geee T]

This was the first time the rotors were turned so they should be fine. I did a few semi hard stops on the way home but didn't drive it to work today so I will try some more tomorrow.

If there is no way for air to get in the lines from just changing the pads then I don't see how it can be a master cylinder or other fluid problem since he didn't touch anything else the first time.

 

[Rusty67]

What kind of break lines do you have ? Stock or steel braided ? If they are stock I would change them and put steel braided on. People never change the rubber lines but they are actually a wear part. Steel ones don't wear out and the reduce compliance in the break system which gives you a more direct pedal feel. Not to say that is THE problem but it is also a worth while upgrade.

 

[sneaky98gt]

If there is no way for air to get in the lines from just changing the pads then I don't see how it can be a master cylinder or other fluid problem since he didn't touch anything else the first time.

Do you have ABS? If you put new brakes on, you have to compress the cylinder back in. If you have ABS, you are supposed to crack open the bleeder on the caliper when doing this to keep the fluid from going backwards through the ABS system. If the cylinders were compressed back in and fluid went backwards through the ABS, it is absolutely possible that air got into the master cylinder. I have personally seen this happen, more than once.

Also, it's very easy to bleed the master. Don't have to remove anything. Just pop the hood and do it.

 

[RedWings44]

Quick question. I have done my share of brake work on my car. What I want to know is; is there any faster way to compress the piston back into the calluper? This one turns instead of pressing, so I can't just use a C-clamp. We have a special tool that you put on a rachet (sp), but I was wondering if there was a way to put it on a drill or something to make it go faster. No immediate answer needed, this is strictly for future reference since I don't plan to work on my brakes for quite a while

 

[Rusty67]

Front or rear brakes ?

 

[RedWings44]

Front or rear brakes ?

Me? I was speaking of my rear brakes. I have never touched the front ones since we have owned the car. The pads still look good, so I haven't had to worry about it. Idk if the front ones have the turning piston or not, but I would assume that they do. Maybe not though. Like I said, I haven't touched them

 

[Rusty67]

There is a special rear brake service tool you need. The calipers don't press straight in, they thread back in. You need a tool that will turn the piston and press at the same time. If you look you will see that there are 2 notches in the piston. This is for the pins on the tool to turn the pistons. You can get a cheap version of the tool from harbor freight these days. I have a 1/2 way decent blue point one that I got off ebay quite some time ago.

 

[RedWings44]

There is a special rear brake service tool you need. The calipers don't press straight in, they thread back in. You need a tool that will turn the piston and press at the same time. If you look you will see that there are 2 notches in the piston. This is for the pins on the tool to turn the pistons. You can get a cheap version of the tool from harbor freight these days. I have a 1/2 way decent blue point one that I got off ebay quite some time ago.

Yes, as I mentioned in my original post, I know this already and we have the tool. Ours attaches to a socket wrench. I was wondering if there were a way to attach it to a drill or something to make it go faster. Thanks though.

 

[Rusty67]

DO NOT USE AN IMPACT.

 

[RedWings44]

Ya, that makes sense. So there is a faster way then?

 

[Rusty67]

I've never tried an air ratchet but to be honest with the tool I use it only takes about 30 seconds to spin the thing back into position.

 

[RedWings44]

Ours attaches to a socket wrench. We don't have anything to make sockets work in a drill...so (as far as it was out last time) it took over an hour. (Yes, by hand). Your tool uses a drill then? Where can I pick one up?

 

[Rusty67]

Not a drill, a ratchet. I was saying you might be able to use an air ratchet. Mine is similar to this one:
http://compare.ebay.com/like/250906831744?var=lv&ltyp=AllFixedPriceItemTypes&var=sbar