Caliper Questions

CDsDontBurn

CDsDontBurn

Seasoned Veteran Poster
Joined
Sep 24, 2023
Messages
970
Location
USA
Vehicle Details
97 Thunderbird Sport
Country flag
Now that I have two of these cars, and as I check RA for parts options, I'm starting to have more questions....

Q1a: Are the front calipers between sport and non-sport identical?

Q1b: Are sport rotors plug and play into non-sport spindles?

Q3: What is the difference in brake lines between ABS equipped and non-ABS equipped?
 
CDsDontBurn said:
Now that I have two of these cars, and as I check RA for parts options, I'm starting to have more questions....

Q1a: Are the front calipers between sport and non-sport identical?

Q1b: Are sport rotors plug and play into non-sport spindles?

Q3: What is the difference in brake lines between ABS equipped and non-ABS equipped?
Click to expand...

1. No

2. Yes but PBR Mustang calipers on non sport rotors are always the better upgrade over sport

3. Brake lines(as in hardlines) or brake hoses? I assume you mean the latter and if so the hoses to the calipers from the hardlines are exactly the same, ABS or non-ABS.

If you are curious about the hardlines all the lines in the engine bay and to the front calipers are different, the routing is the same but instead of going to/from the ABS HCU the non-ABS ones go to a proportioning block in front of the battery. The rear lines from the firewall back are the same, the ABS ones connect to in-line proportioning valves and the non ABS ones simply connect the lines there together with fittings.
 
@XR7-4.6 , your responses have answered some and sparked other questions!

XR7-4.6 said:
1. No
Click to expand...

Then I can swap sport calipers with non-sport calipers, and same with the rotors.

XR7-4.6 said:
2. Yes but PBR Mustang calipers on non sport rotors are always the better upgrade over sport
Click to expand...

Why is this? A larger diameter rotor is always desirable whenever possible. Or is this because of the banjo bolt needing to be modified?

XR7-4.6 said:
3. Brake lines(as in hardlines) or brake hoses? I assume you mean the latter and if so the hoses to the calipers from the hardlines are exactly the same, ABS or non-ABS.
Click to expand...

Yes, I meant the latter; brake hoses to the caliper. Which is also good to know for a better deal / different brand.
 
The rubber lines to the calipers on a 97 are 28 yo. I'd replace them They were ~10 bux When I failed one on Lazarus.
 
Refreshers on some of these questions may be found in the brakes articles section. :)

A large part of the reason why the PBRs are greatly superior to any MN12 caliper is the fact that due to its dual piston design, they can provide a greater, more even clamping force against the rotors. This also effectively eliminates the complication of warped rotors.
 
The rotor size is only one part of the equation. There is also the clamping force, and most importantly the surface area of the pad, which not only helps stop the car, but helps transfer heat out of the rotor. The twin piston PBRs are much better in both those respects, and so the result is a setup that brakes harder, warps less, and is far more fade resistant. Plus it is lighter thanks to the smaller rotor and aluminum caliper, which reduces unsprung weight.
 
@theterminator93 , @MadMikeyL

I knew the PBRs were dual piston already and ergo, have better clamping force and have a larger pad. I was more curious about the rotors themselves in conjunction with the PBRs.

Like, why is it better to do the PBR mod with the non-sport rotors than doing the PBR mod with the sport rotors as mentioned by @XR7-4.6 ? One would think that having a larger diameter rotor is always the more desirable setup, but his response there is having me question why in this scenario that is the opposite.
 
The PBRs are designed for use with 10.87" rotors, not the 11.6" rotors that came on the Sports. The caliper and pad must have the correct geometry for the diameter of the rotor they were engineered for.

OTOH, there is a PBR dual-piston caliper for use with 13" rotors - Bullitt/Cobra calipers - that fit behind 17" wheels. These bolt right on to the '93+ spindles and are a direct swap... however there are no 13" rotors in the MN12 bolt pattern. You need to either redrill the rotors for the MN12 bolt pattern, convert to SN95 hubs, or elongate the holes in the rotors slightly to fit the smaller circle of the MN12 bolt pattern (my choice).
 
CDsDontBurn said:
@theterminator93 , @MadMikeyL

I knew the PBRs were dual piston already and ergo, have better clamping force and have a larger pad. I was more curious about the rotors themselves in conjunction with the PBRs.

Like, why is it better to do the PBR mod with the non-sport rotors than doing the PBR mod with the sport rotors as mentioned by @XR7-4.6 ? One would think that having a larger diameter rotor is always the more desirable setup, but his response there is having me question why in this scenario that is the opposite.
Click to expand...

It’s simply that the PBR caliper won’t physically fit the sport rotor. If you could do both that’s what I’d recommend, however in a world of compromises with the choice between sport rotors/calipers or the smaller rotors +PBRs the latter is the superior setup.
 
@theterminator93 , @XR7-4.6

I just finished reading all the brake articles and it answered my questions, lol.

It is disappointing to know that PBRs will not work with the sport rotors.

Stock 10.8" brakes: 100%
Stock 11.6" SC/Sport brakes: 103%
PBR dual-piston calipers with 10.8" rotors: 122%
PBR dual-piston calipers with 13" rotors: 128%
Click to expand...
 
I have had both; sport brakes are on my Cougar, and my Tbird had the mustang PBR front calipers. They are close in performance, the PBR defiantly have more bite and overall feel a little stronger. However, going from the sport brakes to the PBR fronts with the smaller rotors would be a somewhat lateral move.
Either option is a big upgrade over the stock front brakes, they are so bad I would not recommend them for a daily driver.

I generally like the sports better and would go with them given a choice. Switching over is an easier swap, probably cost less and looks better with the bigger rotors.
 
Questions on the following parts list:

Parts list:
(2) 99-04 Mustang Caliper Brackets
(2) 99-04 Mustang Aluminum Calipers*
(4) Caliper to bracket bolts
(4) Replacement Crush Washers
(1) Set of 99-04 base/GT Mustang Pads
(2) Mustang Banjo Bolts*
(2) Non-sport 10.8" MN12 rotors
Adequate DOT3 brake fluid
3/8"x2' rubber tubing
Click to expand...

What's the difference between the MN12 caliper bracket bolts vs the SN95 caliper bracket bolts?

What's the 3/8 tubing for? The article lists it in the parts list, but doesn't make any reference to it anywhere else. I imagine it's for the bleed process, but I'm not 100% sure on this.
 
It's been a long time; I would assume the slide pins used by the PBRs require a different bolt due to size/pitch differences compared to the MN12 slide pins.

As for the tubing, it's probably to collect fluid during bleeding.
 
Is a special tool needed to compress the rear caliper pistons?
 
The crappy auto parts store cube can actually work ok for compressing the pistons if you remount the caliper to the spindle with the rotor off so you have stability.
 
Does it just have a slit in the middle of the caliper piston instead of the "cup" design?
 
The caliper piston has 4 "V" shaped cutouts at 12/3/6/9 o'clock that you can use to spin it. Spin clockwise and push forward to retract it. I just bought the kit off Amazon for $20 or whatever it was WBW (looks just like the one Dan listed), used it many times.
 
I'll have to get myself a kit then.

I could have used such a kit for my Honda as well, but a big ass flathead worked fine for it.
 
CDsDontBurn said:
I'll have to get myself a kit then.

I could have used such a kit for my Honda as well, but a big ass flathead worked fine for it.
Click to expand...
I’ve said it before and I’ll say it again, mechanics in California are cheating! There’s no way in hell I could use a flathead screwdriver to retract one of those pistons, even on a 2-3yo car out here, let alone something 20+ years old with 400k miles!
 
You must log in or register to reply here.

Similar threads

Back
Top