New Ford Part Number for Rear Calipers

[ddozier]

So every year I replace the rear calipers because Ford and the aftermarket does not have the parts available to rebuild them, I remove the dust seals on the rear calipers at the first pad change because the dust seals are smoked by then. When I ordered the replacements for the ones I carry as backups to the track I was told they have a new part number. So I ordered the new units.

The new units arrived and the only visible difference in the old and new is the new units come with a different material for the dust seals. I am hoping Ford realized the seals where not made from the right material to deal with the heat and redesigned the part. Maybe the "H" in the part number means high heat, who knows but it was worth noting. I will update this thread after the first pad change and see if there is any difference in their performance.

New Part Numbers:
FR3Z-2553-H Caliper Rear
FR3Z-2552-H Caliper Rear

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[Chef jpd]

The updated calipers are black?

 

[ddozier]

The updated calipers are black?

On all the previous calipers I have had the caliper was black and the dust seals were black, on the new calipers I just received the caliper is black and the dust seals are orange.

Dave

 

[boardkat]

must have been a mid-year change. my stock '15 calipers were grey. built in december, 2014; delivered in january, 2015.

 

[ddozier]

must have been a mid-year change. my stock '15 calipers were grey. built in december, 2014; delivered in january, 2015.

Fronts are grey but rears I believe were always black on the GT PP cars, but I guess they could have changed them at some point.

I found some early press photos on Edmunds after they did a long term review and their car had black rear calipers that changed to a chalky black after some use so I guess that could be considered grey. ;)
https://www.edmunds.com/ford/mustan...15-ford-mustang-gt-suspension-walkaround.html

Dave

 

[MaverickGT]

Have you had a failure or are you carrying them as a precaution?

 

[ddozier]

Have you had a failure or are you carrying them as a precaution?

I have not had a failure that has caused an issue on track, but all of the dust seals are always cooked by the time the first set of pads are replaced. That is not really a big deal as my car is only used on track so the dust seals could be completely removed if I wanted to.

I have had one rear caliper leak a small amount of fluid around the piston once the pads got to about 1mm material left. While that did not cause a catastrophic failure I still consider any fluid leaks a failure. Keep in mind the type of fluid you run can cause the soft parts to fail so you have to factor that into your maintenance schedule.

They are so cheap to buy new units ($75.00ea) and only take about 10 min to change that I carry spare calipers to the track and change them at the start of each season to reduce the chance of a complete brake failure on track. If you have ever had the pedal hit the floor at 130mph while trying to brake for a 50mph turn you will never want to go through that again so I may be more cautious than some others.

The fronts I remove from the car and check everything, pistons, seals, dust seals, bleeders, and mounting points at the start of every season. There were no issues with the 6P Brembos after one full season of use. I do keep the front caliper rebuild kits in my track supplies just in case, and I will likely rebuild them at the end of the 2nd season as a precaution.

Dave

 

[Competition Orange]

I have not had a failure that has caused an issue on track, but all of the dust seals are always cooked by the time the first set of pads are replaced. That is not really a big deal as my car is only used on track so the dust seals could be completely removed if I wanted to.

I have had one rear caliper leak a small amount of fluid around the piston once the pads got to about 1mm material left. While that did not cause a catastrophic failure I still consider any fluid leaks a failure. Keep in mind the type of fluid you run can cause the soft parts to fail so you have to factor that into your maintenance schedule.

They are so cheap to buy new units ($75.00ea) and only take about 10 min to change that I carry spare calipers to the track and change them at the start of each season to reduce the chance of a complete brake failure on track. If you have ever had the pedal hit the floor at 130mph while trying to brake for a 50mph turn you will never want to go through that again so I may be more cautious than some others.

The fronts I remove from the car and check everything, pistons, seals, dust seals, bleeders, and mounting points at the start of every season. There were no issues with the 6P Brembos after one full season of use. I do keep the front caliper rebuild kits in my track supplies just in case, and I will likely rebuild them at the end of the 2nd season as a precaution.

Dave

Do you have the dust boot and/or piston part numbers for the GT PP brembos?

 

[ddozier]

Do you have the dust boot and/or piston part numbers for the GT PP brembos?

I have these in my box, they say they are OE direct replacements but I will likely sort the Brembo parts direct once I have time to research the part numbers. At the start of last season this is all I could find in a quick search.

http://www.rockauto.com/en/moreinfo.php?pk=4006971&cc=3307633&jsn=454

Dave

 

[Rypkr937]

If you have ever had the pedal hit the floor at 130mph while trying to brake for a 50mph turn you will never want to go through that again so I may be more cautious than some others.

Interested in how you handled this situation and the outcome of it if you feel like sharing?

 

[ddozier]

Interested in how you handled this situation and the outcome of it if you feel like sharing?

I do not mind sharing, fortunately for me it happened at a track with lots of run off and while I did go off track, way off track, I was able to keep the car pointed forward and use the parking brake and engine braking to bring the car to a controlled stop. This was very lucky for me and taught me a very valuable lesson about not going into panic mode and doing your best to stay in control. This did not happen in the Mustang but it was in a very well sorted track car, with many miles of track use and over 1000 laps at this particular track.

I will tell you that while I was able to get the car back on track, back to the pits, and get the car repaired. I could not bring myself to get back in the car until the next day and even then it took me a session or two to get back up to speed. The brake failure was caused by a failed o-ring on a 10 piston front caliper. On that setup I carried spare pistons as the manufacturer did not sell just the o-rings. I was on my 3rd track year on this particular brake setup and had no issues and no signs of a pending failure. I continued to track that brake setup for another 3 years but I rebuilt the calipers every year from then on as a precaution.

I have found over the years that thorough maintenance will help to reduce the risk inherent to this hobby. I try and share as much safety info with others as I can so that they can decide on the risk vs reward ratio they are comfortable running with.

Dave

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