I was wondering if brake vibration and shudder (all the way up to the steering wheel) could be caused by some loose joints and bushings in the front end suspension (like ball joints, tie-rods, etcetera).

Is it normal to grab a hold of the outer tie-rod end and to be able to twist it a bit? I have a vibration problem when braking, but I am thinking it has nothing to do with the brakes. I am thinking it is something abnormally loose on the front-end suspension.

 

Yes, suspension "slop" will behave as you describe. Ordinarily a tie-rod end will only move the slightest amount, in an up-down direction. This is just tie-rod end pivot motion. You should jack up each wheel, one at time, and try moving the tire back and forth, first at the 3:00 and 9:00 hand positiion and then at the 12:00 and 6:00 positions. There should be almost no play on either account. (some minor play, 1/16 inch is acceptable). If you detect a lot of movement, you will likely need to have an assistant work the wheel while you crawl around looking for the source of the looseness. DO NOT do this without jackstands in place.

Secondly, warped brake rotors will cause a lot of the same issues and are a very common problem on these vans. Improper torque on the lug nuts is the biggest culprit. Once warped, you are better off purchasing new ones. The offshore cheaper ones work just as well as the higher priced ones - if installed properly (i.e. get a torque wrench and do it yourself.) I'll put money on warped rotors as your problem.

 

I always had the warped rotors problem in my 1986 and 1992 Aerostar, they don't last very long before warping. But there is a new generation of rotors being sold at Autozone (Made in China) that are a lot beefier than previous rotors and they withstand warping better.

But the vibration of warped rotors doesn't reflect on the steering wheel column, that must be another issue, like wheel balance.

 

Warped rotors will shake all the way to the steering wheel, as Areocolorado said, very common on the Areostar. I have had my Areo sense 1992, and can not tell how maney rotors we have gone threw in 300,000 miles

 

When you get new rotors, make sure you get the directional versions designed for the 92 and up years. Make sure you install them correctly; the curved vanes should point backward at the top. This helps a bit with heat dissipation.

 

Ok, here is the full story.

The rotors are directional NAPA brand. They are about 2-3 months old.

What happened was the front disc brake pads started to make an extremely embarrassing loud squeaking noise after about 2 months whenever I applied the brakes. What I did was, I replaced the almost new semi-metallic riveted pads with ceramic pads. I did not have enough time to remove the rotors and have them resurfaced. The rotors looked like almost brand new, and the wheel bearings seem to be solid.

I read somewhere that rotors do not warp, it is something on the surface of the brake pads. When I initially replaced the pads everything seemed great, but then the shudders and vibrations came a few days later.

 

Brake pads and rotors are just part of the story. I believe what you have going on are worn caliper slide pins and/or sticking caliper(s). Those slide pins wear and keep the caliper from functioning properly. The caliper cannot release as they should, binding causes the rotor to overheat and thus warpage. Even on a new rotor. At 2-3 months old this is about the only way a rotor would warp that soon. The pins also need to be lubricated during installation with a special, high temp grease.

 

what aero said +

the slide pins in our aeros rely on a compressed (by pin drivein) rubber center to supply tension to keep the pins from sliding out plus small tabs at the end which seldom work.

the rubber decomposes from the high heat of the calipers which bleed off pad heat. gap around slide pins fill with road dirt, brake crud, rust etc creating a sticky non sliding mess.

stuck pin =s stuck caliper =s pads stuck against rotor =s fried rotor and pads.

very poor open design compared to the sealed pins used in other brake apps.

stick with the highest quality semi metallic pads on the Aero, far higher braking friction coefficient than ceramics =s stop faster. transfer heat far better than ceramics which is an insulator.
friction coefficient of semi-M match the rotor design frictional characteristics iron.
ceramics often cut and groove the rotor from being harder than the iron.

ever have a bent warped wheel on the front? will rattle your eyeballs out of their sockets and give you blisters on the palms of the hands from the steering wheel. same principle as warped rotor, same amount of metal there as original, just not in a dynamically balanced state.

 

Addendum to my previous post: I installed new pins and applied plenty of SIL-GLYDE brake lubricant after I thoroughly steel brushed, lightly sanded, and cleaned the pin guide surfaces.

I appreciate the advice concerning semi-metallic brake pads, however in my line of work, they just don't cut it. By the middle of the day, they make a very loud squealing noise which is embarrassing when I apply the brakes.

I realize ceramic brake pads require more effort when they are cold, but overall they are smooth and completely quiet. The first time I had ceramic pads installed on my old 1997 Aerostar, I told the brake shop to remove them because of the extra effort to stop. But now I am sold on ceramic brake pads because they last a longer time, don't make any noise, and are very smooth.

I will be replacing the calipers, resurfacing the rotors, and installing new wheel bearings this weekend to see if it makes any difference. I'm still thinking that the ball joints, tie rods, etcetera, are too loose. I currently have nearly new and balanced tires installed.

The shudder is most noticeable when quickly braking from a very high speed to lower speed.

 

With loose ball joints or tie rods, you can get shimmy and shake without applying the brakes. They can cause vague or darting steering, and might jerk your van to one side when you apply the brakes. As mentioned before, you can check for those by jacking up the front end by the control arms, not the frame. Then grab the tire at 3&9 and try to push/pull. If there is more than about 1/8" of play, then the tie-rod is worn. Then repeat at 6&12, and if there is too much play there, it's one of the ball joints.

If you're only getting the shakes after some hard braking, then it's most likely the rotors are warping. It doesn't matter how new they are, if they've warped once, they will warp much more easily the next time, and just get worse from there. In mild cases, they will go back to sort of flat after cooling off, so they may seem to behave OK for short, light stops. But on the next hard stop, they will warp again. In severe cases, they don't return to "flat" after cooling. Re-surfacing them will not really help, since the temper of the metal has been compromised after the first warpage, and removing metal will only allow them to warp faster the next time they're heated.

The Aerostar brakes are inadequate to say the least, but the real problem is there is no easy solution. The caliper mount does not allow the use of larger rotors, and you can not install a different caliper without machine work on the spindle The best you can do is to find the best rotors and pads available, install them carefully so as to not distort them, and use them carefully.

For example, if you have to apply the brakes on long downhills, remember to downshift out of OD to help prevent overheating them. Often times I have to come to a stop after a long downhill, so I put the transmission into PARK to hold the van in place while waiting for the stop light to change. This eliminates the pressure from the pads that can warp the rotors that just got cooked from stopping the van from the long downhill.

 

I'm with xlt on the permanently warped rotors. No amount of machining inside of safe tolerances will make them safe and wobble free again
waste of money and shop time, some unscrupulous shops will do anything to clean out the customers wallet especially a customer that demands to be ripped off.

had a 1970 429 Cobra Jet that I warped the front discs on bringing it back from 160 mph+ 40 years ago. super heavy duty rotors that cost me a fortune at the time on a GI college student's low wages.
tried turning at a machine shop, actually made them worse.
only avail. were OEM from Ford, what a ripoff.
lesson learned.

 

Thanks for the info XLT and 96.

I have a set of brand new Lomandi CHINA rotors which I purchased about a year ago in my personal parts department closet. I think I will probably make use of them. The only reason I have not used them yet is because they are not vented (the vanes are dam straight).

xlt4wd90: The Aerostar brakes are inadequate to say the least.
I concur 110%, what the h&ll were the Ford Engineers thinking?

Through out this entire ordeal I have become brake conscious, treating them with respect, and giving them a "brake" from the demands that I require of them. I will install the brand new unvented rotors and replace the wheel bearings while I am at it.

Other than that, I still think the ball joints and the tie rods are too loose.
The vehicle still has the original riveted ball joints, and the tie-rods have an incredible amount of spiral movement.

 

They are vented, just not directional, and not as efficient as directional.

It was originally designed as a 4 cyl Shorty van, they expanded the size and power, but as usual Ford tends to neglect the brakes and handling.

Tie rods are super simple, hammer, socket set, and a couple adjustable wrenches and in an hour you can have both sides replaced.

 

UPDATE: I installed the "new" China non-vented rotors and SKF wheel bearings and seals today.

Initial road test results were positive. Brakes were smooth, quiet, and responsive. No indication of vibration or shudder.

The real test will be operating them in an 8 hour stop and go environment for the following week.

 

Hope you used a torque wrench to apply even torque on the wheel nuts. Good luck with the vented, non-directional rotors. (Only some tiny cars have non-vented front rotors.)