[lordvoldemort]

I was replacing my brake pads and I removed the e-brake spring for better access to one of the bolts, only to find out that it's not easy to put the spring back on. So the rear-left brake caliper does not have the spring on it. Then I started noticing too much brake dust on the left front wheel and it turned out that the brake pads on that side were wearing prematurely. I replaced that brake caliper, made sure that the sliding pins are lubricated etc. I don't see as much brake dust on the left front wheel now, but it's still significantly more than the right front wheel. And the brake pad wear on the front left is significantly more than the right front pads.

My question is that can the rear left caliper not having the spring be the cause of this ? Any insights or advice would be appreciated.
Thanks

[Rich J]

So the one that doesn't have the e-brake attached is wearing prematurely? If so then no. Last time I did the brakes on the Mustang I left the e-brake unattached. I had an auto so it was no big deal lol.

[lordvoldemort]

Yes, the one that has the e-brake spring missing is wearing prematurely. The cable is still attached to the caliper, though. It's just that the spring is missing and so there maybe some slack in the cable.

[nasty02v6]

It's virtually impossible for the rear e-brake to affect the front brake pads. It is most likely coincidence. The purpose of the spring is just to keep the e-brake disengaged when not in service. Even without the springs in place you probably wouldn't have any problems, but to err on the safe side, be sure to replace the spring sometime. When brakes are doing what you describe I check for the following:

-Different Pad Brands/Compounds on either side. Sounds crazy but you would be surprised how often I see this.
-Incorrectly oriented "special-compound" pads. Some high-end sets have pads with different compounds for the inner and outer pads. If these are placed incorrectly, they may prematurely wear.
-Worn Caliper Hardware and/or Worn Wheel Bearing. If the guide pin/bolt has "wollered" out the bore it will cause an uneven clamp load when you apply the brakes. This can happen even if properly lubricated. The uneven load can and will tear up pads and rotors. A worn wheel bearing can do the above, but the effects are opposite as the rotor is actually rubbing the pads at inapropriate angles. Of course the caliper itself can be trouble if contaminants (water/grit) have damaged the caliper bores, the pistons can drag and "stick".
-Porous rotors. Many times, mostly on imports, after turning a set of rotors I have found the freshly machined rotors have a porous surface. This has an abrasive effect on the pads and will cause them to wear quickly and screech like hell. Pretty rare, but again i've seen it.
-Poor brake force proportioning. The proportioning valve restricts the flow of brake fluid in order to proportion the brake force. Usually these are used to give the front brakes more power than the rear, commonly 60/40. These valves fail and/or clog all the time. ABS systems commonly provide this effect also as fluid is usually routed to each wheel AFTER passing through the unit.
-Poor fluid quality/flow. Bleed your brakes. If you've never done it, it won't hurt. It gives you the opportunity to check the condition of your brake fluid. Check your brake lines. Flex lines get plugged up ALL THE TIME!

Probably a little more than you needed, but it never hurts to cover all bases. If it was me I would just keep an eye on it. If you're obsessive, you can replace the pads and check the basics and go from there.

[lordvoldemort]

Thanks for this very useful insight. The condition of rotors seem to be the same on either side and I have used the same pads on either side. I also made sure the slide pins are lubed. I have bled the brakes also, but I will do it again, just in case. From the list of causes given by you, clogged brake lines or proportioning valve seem to be more likely. I am not sure about worn wheel bearing, but I would think it would make some noise if that was the case.

Is there a way to check for clogged lines or faulty proportioning valve, other than to just replace it ?

Originally Posted by nasty02v6 It's virtually impossible for the rear e-brake to affect the front brake pads. It is most likely coincidence. The purpose of the spring is just to keep the e-brake disengaged when not in service. Even without the springs in place you probably wouldn't have any problems, but to err on the safe side, be sure to replace the spring sometime. When brakes are doing what you describe I check for the following: -Different Pad Brands/Compounds on either side. Sounds crazy but you would be surprised how often I see this. -Incorrectly oriented "special-compound" pads. Some high-end sets have pads with different compounds for the inner and outer pads. If these are placed incorrectly, they may prematurely wear. -Worn Caliper Hardware and/or Worn Wheel Bearing. If the guide pin/bolt has "wollered" out the bore it will cause an uneven clamp load when you apply the brakes. This can happen even if properly lubricated. The uneven load can and will tear up pads and rotors. A worn wheel bearing can do the above, but the effects are opposite as the rotor is actually rubbing the pads at inapropriate angles. Of course the caliper itself can be trouble if contaminants (water/grit) have damaged the caliper bores, the pistons can drag and "stick". -Porous rotors. Many times, mostly on imports, after turning a set of rotors I have found the freshly machined rotors have a porous surface. This has an abrasive effect on the pads and will cause them to wear quickly and screech like hell. Pretty rare, but again i've seen it. -Poor brake force proportioning. The proportioning valve restricts the flow of brake fluid in order to proportion the brake force. Usually these are used to give the front brakes more power than the rear, commonly 60/40. These valves fail and/or clog all the time. ABS systems commonly provide this effect also as fluid is usually routed to each wheel AFTER passing through the unit. -Poor fluid quality/flow. Bleed your brakes. If you've never done it, it won't hurt. It gives you the opportunity to check the condition of your brake fluid. Check your brake lines. Flex lines get plugged up ALL THE TIME! Probably a little more than you needed, but it never hurts to cover all bases. If it was me I would just keep an eye on it. If you're obsessive, you can replace the pads and check the basics and go from there.

[lordvoldemort]

I am also thinking of changing the brake hose, in case that's gone bad and changing it is straight forward. Changing metal lines does not seem easy, so I would like to know under what conditions can the metal line go bad or clogged? Any inputs are appreciated.

[nasty02v6]

Sorry, sometimes it takes me a while to notice replies.

When you firmly (not "panicking woman" firmly) apply the brakes at 40+ MPH can you feel any definitive "pulling" from the steering wheel? I'm also assuming the rotors are not warped, you would definitely notice and probably would have mentioned it. You also didn't mention if you are applying caliper grease or a similar product on the back of your pads. If you aren't aware of it, doing this dampens vibrations and prevents brake noise and "pad walk". Just don't get anything on your friction surfaces. How thick are your rotors? Are they of equal thickness from side to side? If they are different, they will dissipate heat at different rates causing uneven and premature pad wear. This is why you should always replace or machine rotors at the same time. The same principals above apply to the pads as well. Look for discoloration of the rotors. It usually looks alot like those import exhaust tips with the blueish tint to them, its fine on exhaust tips, not fine on rotors. Discoloration is an indication of excessive heat. How old are your "anti-rattle" clips (the clips your pads slide on)? As they age, they develop corrosion and even warp and won't let your pads slide freely. Most quality brake pads will come with new stainless steel clips. Be sure to lightly grease them (again the caliper grease). This helps your pads move and prevents corrosion/rust and prevents binding which can warp them. You would be surprised how often these little clips are the source of troubles!

Since you have been able to bleed your brakes, a severely restricted brake line is highly unlikely. Standard steel hard lines (not braided) usually don't clog unless there is a major rust problem (water introduced into the system) or something solid introduced into the system. Most commonly it is the flexible lines that can get plugged. This gives a great oppurtunity to replace rubber flex lines with braided stainless flex lines. But I honestly do NOT think this is your problem.

When I check for caliper reaction time and clamp force I do this. I take a lumber 2x4 and cut four small pieces off of it. I place these inside the caliper. I press the pistons in until there is approximately a 1/4" gap between the piston(s) and 2x4. It doesn't have to be a 2x4, just find a quality piece of soft lumber that will fit in your caliper. Be sure it all comes from the same board, this way the material density will be similar. I then hit the brake and pump a few times. Sometimes I do one caliper at a time, sometimes all at once, just depends on what i'm looking for. You can then check out your imprint(s). This gives you a good indication of your clamp force based on the imprint depth and reaction time (the "pop" you will hear when you hit the brake). You can do the math using an estimated wood density/piston contact area/measured imprint depth and figure out the approximate clamping force in PSI for each caliper. That probably wouldn't help you but it is worth a mention.

Worn wheel bearings can be hit and miss. The worst wheel bearing I have seen in my life ('04 Silverado, i'll never forget) was silent and smooth, no indication until I lifted the vehicle up during a safety inspection. Most of the time they squeak, pop, grind, or sound like mud tires on pavement.

I'd hate for you to do any extra work or spend extra money on my account so i'm going to make a recommendation: Lube everything up! This includes the backing plates, anti-rattle slips, etc.. Be sure to observe rotor thickness and discoloration also. Let me know the brand of your pads and if your rotors are aftermarket, their brand as well if you don't mind. Try that first and get back to me. I'll try to help as much as I can.

[lordvoldemort]

Thanks again for the detailed inputs. Very much appreciate it.

When I bled the brakes, I did check and re-lube the sliding bolts and had a good look at the rotors. The rotors are stock and both of them seem to be of equally thick and with about equal wear. They are not warped but they do have the friction lines on them. I didn't pay attention to the color, it seemed black but will take a look again for the blueish hue.
The car does seem to pull just a tiny bit to the drivers side (the side with premature wear) when braking at higher speed. But, at lower speed (25 mph and less), there's no pull at all. About the retaining clips, I used the old ones as they seemed to be okay. I didn't apply any grease but I did clean it with a brake cleaner. I had also applied a anti-squeal spray (blue) on the back of the pads. The pads I used were aftermarket pads from Advance Auto. I think the brand they use is Wearever. I had got middle of the road pads, neither expensive ones nor the cheapest ones.
So I am going to re-lube everything and bleed all four calipers and see how it goes. If that does not fix it, I guess my next step would be to replace the flexible hose.

[nasty02v6]

You can't avoid the friction lines. You can do everything right, buy the best parts, flawless installation, and "BAM", you got grooves. They are merely a side-effect of rotor quality and pad compound.
Do your pads have alignment dowels on the backing plates? For example, I was working on an '04 F150. The driver had allowed the brakes to go metal-on-metal and both rotors and calipers were destroyed. I replaced everything and it tested out fine. After a couple weeks on the road, the truck returned. Heavy brake dust, discolored rotors, and uneven pad wear. I finally discovered that the pads had strangely placed alignment dowels and the caliper was clamping down on them instead of sitting flat on the backing plates. This caused all of that clamping force to be focused on one part of the pad and raised all kinds of hell. Alot of aftermarket brake pads will have minor differences. Some have wear indicators, some don't. Some have alignment dowels, some have alignment dowels in different spots, some don't have them at all. Some have good shims, some have crappy shims, and others have none. Definately something to look out for.
If the car is pulling slightly to the driver's side there is probably a minor issue. Roads are designed to slope from the center out to allow water to drain off. In a perfect world, you could apply your brakes and the car would smoothly pull towards the ditch. It also depends on your front end alignment, a good alignment compensates for road slope.
Im not too familiar with the sprays, but something on backing plates is better than nothing. I'm still an old school greaser!
The anti-rattle clips don't have to be lubed, it's actually very tedious and time consuming. I'm one of the few people that actually do it. I wouldn't worry about them as long as they're clean and straight.

[P-Mo]

If your brakes aren't properly bled will cause the ssame thing.
After all, air can be compressed.
Jim

[lordvoldemort]

The pads seem to be okay. It has alignment dowels but they don't seem to be causing any issues. The pads are also worn evenly (only that driver's side is worn more). I changed the rear-left caliper (the one that didn't have a spring) since I couldn't find a spring by itself. i am not expecting the issue to be solved because of this but I might as well wait a few days to find out. I will probably invest in one of the pressure bleeder to make sure the bleeding is done properly once and for all.

Thanks for all the inputs.