Update:
Thanks, all, for the replies.
I've tried swapping brake pads, but not tires, as they're brand new. (Still could be worth a try.) Re graphic66 's suggestions, I'll check the pads to see if they move easily. As for the rear, in the fairly recent past I've replaced two blocked hoses and both cylinders (yes, they're drum) and unstuck the emergency brake mechanism on one side. I've never found a case on any car when uneven or missing rear braking has any effect on direction, but I don't say it can't happen. A loose rear wheel suspension, on the other hand, will cause the car to lead while your driving, wandering all over the road--that's what this is one did when the rear spring arm started detaching from the rusted-out undercarriage, which is rebuilt now.
The front end man I don't quite trust now had the theory that worn control arm bushings were allowing the the whole control arm-kingpin-wheel assembly to pull back and toe out on braking. With the long pipe as a pry bar, I just couldn't detect that looseness.
Re front springs, see my followup to w113dude.
Original message:
When I replaced the extra wide tires my 113 came with with 195's close to the original size, the ride improved quite a bit, but it brought out a pronounced pull to the right on braking. (The 220 tires hid the problem, since it was all you could do to turn them when you wanted to.) Unlike many such pulls, this is not evident as the brakes start to grab, but only as I press harder. Bringing it gently to a stop a low speed, I don't get the pull at all.
I eliminated uneven braking or tire pressure as the problem (new brake lines, pistons not stuck, recirculated the fluid many times with no bubbles) and took to it a trusted front end shop for diagnosis and, if possible, an alignment. The shop checked it out and decided that to align, they needed to replace:
- left tie rod
-both kingpins
-*all* control arm bushings (four separate kits) on both sides, plus the idler arm bushing (another kit).
The front end man's guess was that the looseness in the right control arm bushings was the cause of the pull. Since the left tie rod was definitely due for replacement, I did that at home and it gave me an opportunity to check some other things. With tie rod and drag link removed, I found:
1. No looseness at all in the idler arm, which I greased.
2. Dead steering damper, which I also replaced.
3. Looseness in the right kinpin only, until I lubricated it. Then it went away.
4. No looseness in any of the control arm bushings that I could detect.
In the process I lubricated everything that could take grease. After reassembly with the new left tie rod and damper, the pull to the right was still there. I rechecked for control arm looseness by removing the road wheel, and seeing if I could get some wiggle using a long pipe as a pry bar. (I'd tried this before, but with the wheel on.) They move a very slight amount, but it seemed due to the flexibility of the metal: there was no movement relative to the pivot mountings. Also, there was no difference between the two sides.
Naturally none of these checks can reproduce what happens when the car brakes. But so far I have no indication that this just-replace-everything approach is going to fix the pull, and in any case it's going to cost in excess of $2500 before I'm done. Does anybody have any ideas?
