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Discussion Starter #1
Hi,
I have recently changed front calipers, pads and rotors. Now, I have a steady moderate pull to the left. At that same time, I also sucked out the brake res. and refilled with new fluid and then bleed the whole system starting at the right rear and moving progressively to the left front. The old stuff had a greenish tinge and was due.

All the parts are new except the calipers which are Ford ones rebuilt. The flow seemed normal on bleeding at all bleeder screws. My helper was on the brake pedal. The pads and rotors are clean and not contaminated. Again, everything is new. All torque specs were followed per the shop manual and CRC brake grease was applied to the caliper slide pins and the pad backing plates per directions to prevent squeal.

I took it all back apart again yesterday and inspected everything. I cleaned the rotor faces again with Brake Clean and checked the pads for any sign of damage or contamination. None found. The ball joints were replaced about 15,000 ago and the tie rods and ends all are good with no play. Nothing was damaged or bent, I don't off road this truck anyway. The tie rods get greased every 5000 miles when I do my oil. Finding nothing, I reassembled and carefully re-bleed the fronts. No change. Again this issue originally cropped up after these new brake parts were put into service.

I have ordered new rubber flex hoses from the frame brake lines to calipers. I have read these can sometimes cause uneven braking if they fail internally. I'm not hopeful but the truck is a low miles (126,000) 7.3 now 19 years old and it wouldn't hurt to change them.

Does anyone have any ideas? I will try to visualize the rest of the steel lines to look for possible damage. Perhaps something was tossed up and hit a line? Could there be air in the ABS Modulator? I have read the symptom of that is spongy brakes all around. I don't have that issue. I have a firm pedal. Just a mild to moderate left pull which slightly worsens on heavy or harder brake application.

I appreciate any ideas you might have.
 

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I'm no expert , but just a couple thoughts here....
Did you break in your new pads ?
Or, there could be an alignment issue that reared its head after jacking up the truck to do brakes.
 

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Discussion Starter #3
The truck was done on a frame lift which was unremarkable. There was no threat to the components of the front end. I have about 1500 miles on the pads now. The issue developed slowly beginning after about 500 miles. The pads are the "Best Quality" NAPA Ceramics. I looked at them 2 days ago and I see no contamination or defects. No brake line or caliper leaks. The dang thing looks like new all around.
 

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But you haven't installed those new rubber lines yet?

That was a good choice and would be my next suggestion. A couple of things can happen when doing a brake job. You might have dislodged a chunk of something while bleeding and it's now stuck in a line. Also, think of how much Flex your old line just got when you were taking the calipers off and moving them out of the way. A crank inside might now have lifted off a piece of hose inside, causing a blockage.

You stand a good chance of a bad hose being the cause (unless you've already changed them ;) )
 

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A hose pull will increase in severity with brake pressure.

The first thing I would do is get an inexpensive infrared gun and check rotor temps (in the center of the swept area) at the time of the pulling.

Brake pulls can be readily felt when you have an axle side to side imbalance of 100ºF. Some notice it slightly lower in the 80º range.

You went through the slide pins, but did you check how freely the pads slide back and forth in the bracket? Aftermarket companies get their steelbacks from different sources than the OE, and they typically are not as tight in width specs (+-0.010" vs OE -0.010"+0.000"). The aftermarket also does not control their paint application as well, so that can also cause some hangup.

The 2001 MY uses the Akebono calipers, and in the 2001-2002 time frame started to incorporate the wishbone springs on the top of the pads to help push them away from the rotor, which will reduce non-braking contact and temperature. Were those used with these aftermarket pads?

Imbalance temps were a big issue early in production. So was an issue of the pads came from different batch mixes. There was a TSB early in production to get the OE pads changed if the batch numbers were not the same. These trucks have a high scrub radius so they are sensitive to torque imbalance in braking, the same as front wheel cars were on acceleration before srub radius changes.


TSB 03-19-10 99-03 F-Series, 2000-01 Excursion Brake pull:
There are several problems that may contribute to this condition.

First, the vehicle should be driven to determine if the pull/drift occurs at all times, or only when braking. If it pulls at all times, the tires, tire pressure, steering, suspension, and alignment should be checked. Also check for a dragging/sticking caliper, steering gear control valve leakage, and an imbalance of loaded or added components.
If the pull occurs only when braking, check for contamination of the brake materials. Check the edge code on the pad lining should be checked to see that all four have the same batch number (the numbers preceding the "/" in the code). If the codes do not match, replace the pads, ensuring the code matches on the new pads, and resurface the rotors. If the codes match, swap the pads and rotors side to side. If the pull follows the brake parts, replace the pads and resurface the rotors. If swapping the pads does not reverse the direction of the pull, check caliper for sticking or binding and the hoses for restrictions. Also, check the ball joints for binding.

On 4X4 trucks only: If the pull does not occur during light to moderate braking at speeds of 35-40 MPH, but does occur on moderately hard braking at speeds of 55-65, replace the front leaf springs (see TSB for chart). If the build date is between 3-20-99 and 11-25-01, replace the steering gear (2C3Z-3504-AARM) and pitman arm (YC3Z-3590-CA), set the gear mesh load to 5-6 in/lbs and adjust the alignment to specs with a cross caster of -0.5° (right caster 0.5° higher than left).
 
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Discussion Starter #6
But you haven't installed those new rubber lines yet?

That was a good choice and would be my next suggestion. A couple of things can happen when doing a brake job. You might have dislodged a chunk of something while bleeding and it's now stuck in a line. Also, think of how much Flex your old line just got when you were taking the calipers off and moving them out of the way. A crank inside might now have lifted off a piece of hose inside, causing a blockage.

You stand a good chance of a bad hose being the cause (unless you've already changed them ;) )
Yes, Thanks... No I'm still waiting for the hoses and crush washers. I hope this does it.
 

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Discussion Starter #7
A hose pull will increase in severity with brake pressure.

The first thing I would do is get an inexpensive infrared gun and check rotor temps (in the center of the swept area) at the time of the pulling.

Brake pulls can be readily felt when you have an axle side to side imbalance of 100ºF. Some notice it slightly lower in the 80º range.

You went through the slide pins, but did you check how freely the pads slide back and forth in the bracket? Aftermarket companies get their steelbacks from different sources than the OE, and they typically are not as tight in width specs (+-0.010" vs OE -0.010"+0.000"). The aftermarket also does not control their paint application as well, so that can also cause some hangup.

The 2001 MY uses the Akebono calipers, and in the 2001-2002 time frame started to incorporate the wishbone springs on the top of the pads to help push them away from the rotor, which will reduce non-braking contact and temperature. Were those used with these aftermarket pads?

Imbalance temps were a big issue early in production. So was an issue of the pads came from different batch mixes. There was a TSB early in production to get the OE pads changed if the batch numbers were not the same. These trucks have a high scrub radius so they are sensitive to torque imbalance in braking, the same as front wheel cars were on acceleration before srub radius changes.


TSB 03-19-10 99-03 F-Series, 2000-01 Excursion Brake pull:
There are several problems that may contribute to this condition.

First, the vehicle should be driven to determine if the pull/drift occurs at all times, or only when braking. If it pulls at all times, the tires, tire pressure, steering, suspension, and alignment should be checked. Also check for a dragging/sticking caliper, steering gear control valve leakage, and an imbalance of loaded or added components.
If the pull occurs only when braking, check for contamination of the brake materials. Check the edge code on the pad lining should be checked to see that all four have the same batch number (the numbers preceding the "/" in the code). If the codes do not match, replace the pads, ensuring the code matches on the new pads, and resurface the rotors. If the codes match, swap the pads and rotors side to side. If the pull follows the brake parts, replace the pads and resurface the rotors. If swapping the pads does not reverse the direction of the pull, check caliper for sticking or binding and the hoses for restrictions. Also, check the ball joints for binding.

On 4X4 trucks only: If the pull does not occur during light to moderate braking at speeds of 35-40 MPH, but does occur on moderately hard braking at speeds of 55-65, replace the front leaf springs (see TSB for chart). If the build date is between 3-20-99 and 11-25-01, replace the steering gear (2C3Z-3504-AARM) and pitman arm (YC3Z-3590-CA), set the gear mesh load to 5-6 in/lbs and adjust the alignment to specs with a cross caster of -0.5° (right caster 0.5° higher than left).
Great reply! Thanks for all the info. I really appreciate it. I'll report back when I find out the cause and eliminate it.
 

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The things that come to my mind are;
Bearings, caliper slide pins, caliper and brake lines. These are the most common causes of what you are describing.
Since you have the hoses on the way, when those go on, make sure the slide pins are lubed and the bearings aren't loose.
 

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If you are suspecting fluid not returning in the system, then open the bleeder a little
a socket will help with fluid squirting out -- it may be hot, so dont get burned
if fluid squirts out and the wheel rotates freely -- then it is not a mechanical problem
 
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Hi,
I have recently changed front calipers, pads and rotors. Now, I have a steady moderate pull to the left. At that same time, I also sucked out the brake res. and refilled with new fluid and then bleed the whole system starting at the right rear and moving progressively to the left front. The old stuff had a greenish tinge and was due.

All the parts are new except the calipers which are Ford ones rebuilt. The flow seemed normal on bleeding at all bleeder screws. My helper was on the brake pedal. The pads and rotors are clean and not contaminated. Again, everything is new. All torque specs were followed per the shop manual and CRC brake grease was applied to the caliper slide pins and the pad backing plates per directions to prevent squeal.

I took it all back apart again yesterday and inspected everything. I cleaned the rotor faces again with Brake Clean and checked the pads for any sign of damage or contamination. None found. The ball joints were replaced about 15,000 ago and the tie rods and ends all are good with no play. Nothing was damaged or bent, I don't off road this truck anyway. The tie rods get greased every 5000 miles when I do my oil. Finding nothing, I reassembled and carefully re-bleed the fronts. No change. Again this issue originally cropped up after these new brake parts were put into service.

I have ordered new rubber flex hoses from the frame brake lines to calipers. I have read these can sometimes cause uneven braking if they fail internally. I'm not hopeful but the truck is a low miles (126,000) 7.3 now 19 years old and it wouldn't hurt to change them.

Does anyone have any ideas? I will try to visualize the rest of the steel lines to look for possible damage. Perhaps something was tossed up and hit a line? Could there be air in the ABS Modulator? I have read the symptom of that is spongy brakes all around. I don't have that issue. I have a firm pedal. Just a mild to moderate left pull which slightly worsens on heavy or harder brake application.

I appreciate any ideas you might have.
You are on the right track replacing the rubber lines whether they are the problem or not. A little trick I learned from motorcycle front breaks may help. Instead of bleeding in the usual manner suck the fluid out of the front brake reservoir. Use new fluid to fill it back from the caliper bleeder. You will then push ALL air out and anything that may be restricting the line at the same time. This has fixed brake problems many times over the years and no need for someone on the peddle. Next time try this before you replace the lines. Good luck with it.
 

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Discussion Starter #11
Problem solved by replacing the rubber hoses.
 
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