Ok so a routine brake job turns into........

[demarpaint]

A royal PITA. I got around to doing my front brakes on my 93 Aerostar. The rotors were in need of replacement and it was time. New front pads, rotors, and wheel bearings. I also replaced those caliper pins that Ford uses to hold the calipers in place. Everything went together fine, problem is when I stop it feels like a tire blew out. This certainly isn't the first brake job I did, but it is the first time this happened. Spinning the rotors there doesn't appear to be anything warped or out of round.

Side note new calipers were cleaned before installing, no oil or anything else was on them. No clunking or banging, everything feels nice.

After about 2 miles of driving I took the wheels off and double checked everything, it checked out OK.

As always TIA, suggestions are welcome.

 

[The Critic]

What do you mean by a tire blowout? Could you describe that a bit better?

 

[demarpaint]

I guess thumping would have been a better term. It tracks straight and true, but feels like the thumping you get if a tire blows out.



Edit to add:

After about 5 or so miles of driving it improved slightly.

 

[5150ds]

Does it have ABS? Might be the ABS system kicking in.

 

[demarpaint]

No only rear ABS, this is coming from the front.

 

[mechanicx]

Are the wheel bearing adjusted right?

 

[Bluestream]

Caliper bolts tightened??

 

[flacoman]

Spindle face clean?

 

[demarpaint]

Ford doesn't use bolts for the 93 Aerostar they use calpier pins, that are basically hammered into place. It is hard to explain unless you've worked on one of these, but there are no nuts and bolts that hold the caliper in place. A stupid design, they used it on the E-150 vans as well. Never a problem, until today, but there are better designed braking systems.

 

[demarpaint]

Originally Posted By: flacoman
Spindle face clean?


Spotless.

 

[demarpaint]

Could a bad stabilizer link bushing cause my problem? Something I haven't checked, it just dawned on me. I thought I'd toss that out there.

 

[The Critic]

Is the ABS activating? If so, check to see if any of the sensors were contaminated or damaged during the brake job.

 

[demarpaint]

The car has Rear ABS only, nothing is activating. The problem is coming from the front of the car.

 

[chrome]

I know this sounds silly, but did you properly tighten and torque down the lug nuts? I once forgot to tighten them after a brake job, and went for a drive, and it made the same noise as you are describing, sorta of a rumbling thump thump thump.

 

[demarpaint]

Yes, in fact I took the wheels off a second time, to check my work. I torqued them down both times with a Torque wrench. I ran them down to 95 foot pounds.

 

[eljefino]

This sounds goofy but it worked for me once, switch the inboard and outboard pads if they're symmetrical and the little wear reed thing fits. Yeah you think it wouldn't make a difference on new pads but...

 

[demarpaint]

These pads can't be switched. The outboard pad has special spring steel hardware built into it to hold it to the caliper.

 

[1kickbuttranger]

Warped rotors??
Where did you get them from? Brand?

 

[demarpaint]

I forgot the brand, they were the garbage from AAP. The vehicle is pushing 185,000 miles, I want it safe, but I didn't want to break the bank buying parts.

I'm going to use it tomorrow and see what happens. My fingers are crossed that there might be a touch of grease on a rotor, causing the problem. But I think that's wishful thinking on my part!

I have a feeling the right front rotor is warped. I was busy tonight, but will spend some time with it tomorrow or Thursday. It figures, I change rotors with over 100K on them, for new junk.

 

[doitmyself]

Did you use the spray-on adhesive disc pad backing you talked about in your brake grease thread?

Pads with shims are not supposed to get this treatment (if you go by the book or read the CRC label). Light application of brake grease on the back of the shims is helpful to allow the pads to move a bit in there holder and dampen noise. Maybe the anti-squeal paste (assuming you used it)buggered something up. Just a hunch.