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First, let me say that I have benefited greatly from the information that others have shared on this site. I am posting this because I want to reciprocate.
The subject here is upgrading the (front) brakes. 13" brakes were decent back in 2000, but the standards for braking have gone up significantly since then, and people in front of you will stop up to the limits of their cars. If you run into them, you will be held responsible. Add into the equation larger wheels and tires (I have the OEM 20s), and especially if you carry or pull much, you will probably want to upgrade the brakes. I have been researching how to do this for some time. I had identified three possibilities:
1. Buy the TCE Wilwood 16" kit. I have the 20" wheels to allow it, but a) the price is more than I want to pay for the project, b) I had reservations about going so far away from Ford parts (proprietary calipers, rotors, pads, etc) since I routinely transfer the vehicle to a friend who drives and maintains it when I am overseas.
2. Use '99-03 F450/550 14.5" brakes. This involves pulling the solid front axle from one of these trucks and installing it. It works because the rotor/hubs actually used the Excursion bolt pattern back then. The problem is that I already have an aftermarket lift and coil front suspension kit that would not work without some welding/fabrication on these leaf-spring solid axles. Also, despite the rotor size, the swept area (which is the crucial thing) is really not that much bigger.
3. Use the '13-current 14.29" brakes by doing the conversion to the newer, wider front end (which means you can run the '05-current wheels without using spacers, and the ride and turn circle are improved). In the case of my 2wd, this would involve the better part of a conversion to 4wd. In addition to being a lot of money for parts (the newer Super 60 axles are roughly double the price of old F450/550 solid axles), this would be a lot of shop time for me to pay for since I have neither the time or the tools to accomplish it myself.
However, after too much research at looking at online Ford parts diagrams, I came up with a 4th option:
4. Use the '13-current 14.29" brakes by changing the spindle/knuckles to the '13-current part. I had no idea this was even possible until recently. I mean, think about it: what are the chances that Ford kept the same basic twin I-beam parts so that the '13-up spindle/knuckles would work with the '99-'04 design? It turns out that they did, and not only that, but they retained the design for the new ('17-current) generation! I didn't really believe it until I saw the identical part numbers on the crucial part of the I-beam.
So that is what I did. Here are the parts needed:PartFord part noPart make2013-16 2WD Spindle/knuckle RH passengerDC3Z-3105AFord2013-16 2WD Spindle/knuckle LH driver DC3Z-3106AFord2013-16 2WD front brake caliper w/brackets RHBRCF-258Raybestos PG 2013-16 2WD front brake caliper w/brackets RHBRCF-258Raybestos PG 2013-16 2WD front brake rotors 14.29" BRRF-311Power Stop drilled and slotted2013-16 2WD front brake pads BRSD-1680Power Stop Evolution Clean Ride2013-16 2WD ABS sensors ? Ford
You also may need the bracket bolts and the castle nuts and bolts, etc, depending on your source of parts. If you are running wheel spacers, you will need to get a new set of fine-thread lug nuts to fit the new lugs. [EDIT: unnecessary because, as I soon found out, you no longer need to use wheel spacers!] If you have a 16" spare tire it will no longer work, so you should get a new one (Ford uses a 17" spare on the new trucks; I have not tried it, but it must just barely clear. I doubt a slightly thicker material on a 17" alloy would work. Alloys would be 18" minimum.
Here are some pictures. It is difficult to grasp how much bigger the calipers are compared to what I had.
So it's all on and it works--it will stop when and where you need it to now--but a few issues remain.
1. ABS! The reason why I don't have a part number for the ABS sensors is because we still haven't figured that out exactly. We ordered what was listed for a 2014 F250 2wd, but the sensors somehow would not fit in the new hub/rotors. If anyone has some clues on that, please tell me. The independent 4x4 shop I used is now looking at an E350 part they think will work. In any case, they will have to splice the connector.
2. The pedal (this is a non-hydroboost vehicle) is even softer than it was before. I was hoping that the bleeding of the system would improve things, but no such luck. Of course, I knew the the larger pistons would require more fluid to move them, but it is a little more than I thought. The right way would be to install the current master cylinder (or hydroboost conversion, but I don't like the hum), but are there any other, easier options to improve pedal feel?
3. This is minor, but the tires now rub a little (see picture). Although none of the new parts individually look wider, the whole thing is in fact a little wider. In addition, the new knuckles have reduced the crazy tow angle when turning. This should fix the badly uneven tire wear I used to have, but these two factors together mean that the tire rubs. I will just get out the file and file the plastic a little.
Your now larger front calipers need more fluid from a larger master cylinder, the problem isn’t if you use the newer larger master it will deliver more fluid then needed to the smaller rear caliber bores.
remember a larger bore master will make less pressure but move more fluid. The trick being to match the volume need to move the caliper piston the correct distance and generate the pressure needed at the brake pad with the desired pressure at the brake pedal while still using a reasonable pedal stroke. ( the brake pedal leverage ratio plays a big role in that and I have never compared the 99-04 lever to a newer one, for all I know they may have changed the ratio )
Sadly I no longer have the data sheets available to help you with the math, maybe call TCE and see what they recommend.
on our race cars we get around the problem with diffrent size front and rear master cylinders with a balance bar.
Your older generation ABS module will not speak the language of the newer sensors, so even if you find one that will fit it won't work. You need to see if your old sensor will fit in there.
Your older generation ABS module will not speak the language of the newer sensors, so even if you find one that will fit it won't work. You need to see if your old sensor will fit in there.
good call on the older style passive AbS vs the news Active systems.
Also, since you are going to have to retrofit your passive sensors into that knuckle remember the 2wd uses a diffrent sensor then the 4wd and that the Air gap is highly critical on the setup, I don’t have the actual specs ( but may be able to get them ) but you could always assemble your old one and measure the air gap.
A good machinist should be able to modify your new knuckle to mount your old sensor with the correct air gap. But before taking that step I would also compare the tone rings to make sure they are the same.
EXSwap: Thanks very much. It's definitely satisfying to see those parts come together on the truck.
pirate4x4_camo: Thanks so much for all the great info. Since separate master cylinders are not an option, do you think moving to the new MC would be better or worse than sticking with the old? Also, great tip on how to solve the ABS issue. If you happen to have the specs on the air gap, that would be great to know.
Nicmike: Thanks so much for that crucial insight regarding the ABS system--you certainly saved me some time and frustration.
Bill, I also went to a bigger brake system with the 07 axles I put under my X. I had to re-use my old style sensors to keep the ABS working. Luckily, mine fit right in the newer axles without having to modify the holes/hubs. Did you swap to the newer rear axle for the bigger brakes on the rear, or just the front so far?
Bill, I also went to a bigger brake system with the 07 axles I put under my X. I had to re-use my old style sensors to keep the ABS working. Luckily, mine fit right in the newer axles without having to modify the holes/hubs. Did you swap to the newer rear axle for the bigger brakes on the rear, or just the front so far?
A rear axle swap is dead simple.
Mike,
IIRC didn't you do the rear axle when you converted yours ? i recall suggesting the 07 master to match your setup.
Mike,
I have only done the front so far. Which front rotors and which master cylinder do you have? The '05-12 MC designed for the 13.66" rotors seems like a possible compromise solution for me.
pirate4x4_camo: Thanks so much for all the great info. Since separate master cylinders are not an option, do you think moving to the new MC would be better or worse than sticking with the old?
simple answer, use the master that matches the front brakes, ( my best semi educated guess without doing all the math )
but the real answer is far is far more complex then that.
first your should read and understand every word of this Brake System and Upgrade Selection
but make a special note front rear brake bias and the part where if your rear brakes lock up first you will over steer and spin out.
once you do all the math after researching the various caliper bore sizes and then converting that to piston area,
you “should” come up the conclusion the rear static clamping force is similar But because the rear rotors are smaller in diameter they generate less braking torque and therefore should not lock up before the fronts. I say should but I may very well be wrong as I am not an actual brake engineer and since you may crash and die as a result you need to verify
you “should” come up the conclusion the rear static clamping force is similar But because the rear rotors are smaller in diameter they generate less braking torque and therefore should not lock up before the fronts. I say should but I may very well be wrong as I am not an actual brake engineer and since you may crash and die as a result you need to verify
Wouldn't an aftermarket proportioning valve solve this ?
All,
My apologies as we have been on vacation. I spent some time tracking down the numbers for the master cylinder bore and caliper pistons. The numbers were a little confusing to me, so I thought I would put them out there for correction or explanation:
Excursion
Master: 1.375" (w/hydroboost 1.375'')
Front: 2.12" 53.90 mm
Rear: 1.75" 44.32 mm
2005-2012 F250
Master: 1.313''. (w/hydroboost 1.5'')
Front: 2.36" 59.84 mm
Rear: 1.89" 48.01 mm
Why did Ford actually decrease the MC bore size for non-hydroboost?
In any case, the difference between 1.375" and 1.313" does not seem worth the re-plumbing involved. I am guessing the original MC is worn, and will simply replace it, and hopefully that will be good enough.
All, My apologies for not replying; we just got back from a weeklong vacation.
I have tracked down the numbers to run the formula Pirate4x4 suggested. I was expecting that the '05 MC would have a larger bore, and that the '13 would have an even larger bore. Neither of these things were true for the non-hydroboost. Here is what I found:
So, running those numbers through the math (assuming 6:1 pedal ratio and 50 lbs of foot force), I get
Line pressure with my 1.375" MC = 202 psi
Line pressure with a 1.313" MC = 221 psi
1. Are these numbers right?
2. Why did Ford reduce the MC bore size when they went to larger brakes? Was it because they were first splitting the difference by using just one MC bore for both hydroboost and vacuum, and then they went to different MCs that suited the different systems more precisely?
3. Running the numbers, the difference to changing the MC to 1.313 would be 10% greater line pressure but 10% less volume. Not sure if that is worth the re-plumbing that I would need to do to change the output side from right to left.
4. It looks like there would be almost no impact either way with the rear brakes; the 1.375" had the 1.75 rear piston and the 1.313 had the almost identical size 1.77" rear piston.
5. Looking at the front caliper numbers, it looks like the reason for the increased pedal travel is not so much the slightly larger front pistons (2.36 instead of 2.12, an 11% difference) but that they are distributing that force by squeezing much larger brake pads (they look absolutely huge in comparison to the original 2000 pads).
In any case, the brakes worked great on the trip, and I am looking forward to putting in a new MC and getting the ABS sensors machined to fit.
Finally, for those running the OEM Michelin LTX AT2 275/65r20 tires, they really seem to like 80 psi on the highway. I had let them get down to 70 (that is all the usual gas station pumps will do) but I went to a truck stop and used a big rig air hose to set 80 all the way around--the steering tracking was MUCH better, the noise was reduced and the MPGs went up .5.
Wouldn't an aftermarket proportioning valve solve this ?
Never tried it because because my racers do t have ABS but the engineer guys say not to use a proportioning valve with ABS since it already modulates front to rear bias.
08-03-2018, 10:40 AM
