Learn Me "Sticky Caliper"

1995 Lincoln Continental pulls left under hard braking ...but it feels as if it's trying to correct itself. Almost like it's rotating about the left rear wheel. That's where most of my inspecting has been.

I've gotten used to it. SWMBO wants it right!

It's been doing this since I first put it on the road a year or so ago. It got new pads all around right away. (Everything was worn evenly at the time.) After that, no better.

Pistons all moved smoothly during the change, guide pins appear to be OK and lots of fluid flows during subsequent bleeding.

Over the years when someone would bring me a car with a "sticky caliper" and a pull, the problem was inevitably the lower ball joints. I changed those on this thing, too. One was sloppy loose and I was confident the problem was solved. (It wasn't.)

So, oh great collective GRM mind, what do I try next, without resorting to wildly throwing new parts at it?

Desperate in Delaware

edit: Changed the orginal upper case "FIXED" to lower case "right" so someone scanning wouldn't scan and skip.

do the pads show uneven wear? compare inboard to outboard on both sides, as well as compare left inboard to right inboard, and left outboard to right outboard. if pads are wearing evenly, then start looking at control arm bushings.

How's the tire wear? I wonder if it could be warn bushings that are causing alignment changes under breaking...

Pads look even side to side (and inner versus outer) and tire wear looks even.

I've been thinking suspension movement, as well, but don't have a clue where to start looking. None of the bushingsthat I can see appear like there's been any movement.

Nothing moves with hand pressure.

Assuming it has rubber lines at each wheel, what shape are they in?

I don't know about Ford products, but I have seen several cases of GM rubber lines failing internally causing brake issues. The usual symptom for this tends to be a dragging brake due to slow pressure release, but no bleeding problems. It wouldn't surprise me if it caused other problems during the initial failure that your average driver might not notice but someone more in tune with the vehicle would pick up on.

Any chance the other side isn't working well making it seem like the left is dragging, when it's really that the right isn't working properly?

Does any wheel seem warmer or colder than the others?

Joe

Haven't monitored wheel/brake temps. Maybe I should start.

I kinda guessed the amount of flow when bleeding would be an indication of hose condition. Yes/no?

Two other points: Each side has a small horizontal shock absorber running from the rear of the upper A-arm (Yes, it's IRS.) to the body. I believe these are called isolation dampers. I understand their use in RWD applications to resist axle wrap, but on the rear end of FWD???

I read tonight about the "high rate of rear suspension bushing failures." That would make sense but I only saw it listed once. High rate? ...and shouldn't I be able to see a witness mark if the bushing was shifting even slightly?

In most cases you'll never get movement out of a busing using hand pressure. Large channel locks and pry bar are the tools of the trade.

jstand wrote: Assuming it has rubber lines at each wheel, what shape are they in? I don't know about Ford products, but I have seen several cases of GM rubber lines failing internally causing brake issues. The usual symptom for this tends to be a dragging brake due to slow pressure release, but no bleeding problems. It wouldn't surprise me if it caused other problems during the initial failure that your average driver might not notice but someone more in tune with the vehicle would pick up on. Any chance the other side isn't working well making it seem like the left is dragging, when it's really that the right isn't working properly? Does any wheel seem warmer or colder than the others? Joe

I agree that the brake hoses could be the issue.

The Dodge Neon I picked up as a DD a couple months back had a similar issue. Step on the brake pedal and the car would pull to the right hard. I checked the drivers side of the car first and found the issue. The brake hose was junk which caused the caliper to stick and it wasn't working at all.