I like to drive fast ****ing gears with stick and I learned, that aero's rear brakes are not the best. I want to equip my aero with rear disk brakes and to install Haldex EBS (ABS+EBD) for better baking.

Your opinion...?

 

I'm all for better brakes, but I think the Aero's (and most unloaded pickup trucks) barely use their rear brakes in most stops, as most of the weight is shifted forward during braking. I would work on improving the front brakes first for better results. I say this first because this is what I would like to do, but I don't see how without modifying the spindles for mounting larger calipers to accommodate larger rotors, like from Wilwood or Brembo.

Having said that, I think you can get the rear axle shafts and backing plates from certain years of Explorers to fit in the Aerostar's rear axle housing, and bolt up the calipers with the proper spacers. You will also need to install some kind of pressure reducer in the rear brake line, or else the RABS will be working overtime to prevent the new rear brakes from locking up.

 

The rear brakse are more that adequate. It is true, that as more brake is applied, the RABS system diverts more power to the fronts, not the rears. 4WD90 summed it up nicely.

 

I can say that the rear brakes do make a noticeable contribution to stopping. When I drove my van to the junkyard, I had front-only brakes. The rear line had started to leak, so I pinched it closed with vise-grips to keep the fluid from running out (it worked too). But it certainly reduced the amount of braking I could achieve overall.


I would think that if you were determined to convert to a rear disc, Mustang parts would be were to start. Explorers always had the 31T 8.8" axle, which has larger diameter axle shafts, which in turn means larger outer wheel bearings, which means larger axle tubes, which then means a larger mounting face and bolt pattern for the backing plate. Long story short - Explorer brake assemblies will not bolt onto an Aerostar axle. The rotors may have the right hole pattern, but that's the only feature that's right.

The 1994-2004 Mustang rear discs should be a lot closer to being a bolt-on, since it also used 28 tooth 7.5" and 8.8" axles. The axle end should be the same, so the backing plate bolt pattern ought to be the same as well. Then it's just a matter of whether or not the offset between the axle shaft flange face and the backing plate is close enough to allow the caliper to actually fit over the rotor properly. The only other issue that be a problem is rigging up the e-brake cables. I have no idea whether they'd be similar or not...

 

I agree that front brakes are where more power is needed. I once found a website that tested brakes for police cars and Hawk linings came out best. You might want to try to find this site and try higher performance linings. Cheapest and easy.

Ken

 

NLECTC.ORG provides this test data. there are apparently great differences in linings.

Ken

 

A lot of people quick to jump to big brake upgrades don't realize that they can see significant improvement by making the most out the stock brakes with better pads and shoes. I would think it's definately worth trying different pads out to see which ones are better for you before trying to fabricate an expensive upgrade. IIRC, there are still Hawk pads available for the Aerostar. There are also companies out there that will custom cut lining material for your specific pad shape, so even if there's nothing off the shelf, better pads can still be found.

 

Rick,

It's odd you should mention Mustangs, as one of the disk brake swaps for Fox3 Mustangs is to use those same Explorer axle shafts I referred to. I just can't remember what years were the candidates. I'm sure they're all 28 spline.

The parkng brake cables will almost certainly be different; the lengths will be different, as will the anchors for the cable stops. You can change the cable lengths by cutting and then crimping new ends onto them, but I'm not sure how to modify the outer sheath.

 

Well. There is anought room under the aero and I can install parking brake on tranny to lock the driveshaft, like on russian military trucks.

 

The Explorer has had 31T shafts since day one. The early trucks had drum brakes, but otherwise the axle hasn't really changed up to the '02 redesign. It could be that the Fox body conversion also somehow included a 31T swap, but the 31T shaft will not fit in a 28T housing/tube assembly. I have seen that Ranger shafts can be used in Fox-body disc brake conversions, but not Explorers. This site has some good insight into that, although it's more intended for 4 to 5-lug conversions on Cougars/T-Birds, but they're still Fox-body cars...
www.coolcats.net/tech/advanced/4to5lug.html

 

I didn't see anyone mention heat. If you are going to autocross your Aero you might want to look into drilled/slotted rotors up front. Stainless braided lines may give you a better brake pressure feel too.

 

Well, that would be a sight to see. I have actually taken my Aerostar to a bunch of autocrosses myself, but that was with a gokart and tools/supplies in the back...

FWIW, though, drilled/slotted rotors aren't really a benefit to a street car. Yes, purpose-built race cars have drilled slotted rotors, and those rotors are designed to have those holes and slots in them. Those features help reduce the unsprung/rotating mass and can help cool, and the rotor is sized and structured to account for the material removed. Same goes with brake rotors on motorcycles.

Most any drilled or slotted rotor that you buy for a street car start off as a standard rotor and are then machined. That means that, structurally, they aren't designed to have those slots in them and they've just been weakened. Removing material from the rotor also reduces the surface area of the rotor's swept area, which in turn means that there is less friction area for the pads to contact. Furthermore, removing material degrades the rotor's heat sink ability - i.e. it's ability to absorb heat without fading - or warping for that matter. About slots providing a place for the gases emitted from the pads to go, well, modern brake pad compounds (especially high performance ones) don't offgas. So, unless your brake linings were made in the '50s, this isn't a real issue. And finally, about the helping brakes cool/dissipate heat, well, unless you've run duct work to flow air directly on the brakes, then you won't see a difference there at all, especially if the air flow to the rotors is blocked off by the stock Aerostar wheels. You need to actually route cold air to the brakes in order for cross drilled holes to effectively be used.

Conclusion? Purpose-built brake systems for race cars benefit from drilling/slotting. Drilled/slotted rotors on street cars are just bling, nothing more. There is no performance benefit, in fact there are a number of reasons why they'd perform worse. Not a great plan in my book...

 

I agree with Rick! Better linings with a better hi temp friction rating, the second letter in the edge friction code (FF, FE, etc.) is the hot friction coefficient. That police car brake test I mentioned earlier has some good info.

Ken

 

Well, rear disk brakes is just a first step.
The second step - is to prepare brake system to abs.
So I need to add 1 brake line to rear wheels.
And I need equal teeth number on front and rear rotors, becouse I want to drill a caliper and install wheel speed sensor to it.

 

Rick,

You are correct...it was Ranger, not Explorer, axles that were used for certain Fox3 rear disk mods. We tend to lump Aeros in with Rangers and Explorers because we think they're so similar, but they are different in many ways.

A lot of the guys who road race often complain of "green fade" when using new brake pads, even "high performance" versions. Their theory is that new pads will outgas the first few times that they are heated up during operation. Is that actually a pad bedding problem, or are they making this up?

I'd really like to find a way to adapt my Cobra calipers and rotors to my Aero. That will give me an excuse to spring for the Brembo conversion for my Mustang.