[mirada6.0]

I did the searching (lots of threads!) but still have a question. I just re-insured the car, aired up the tires, etc., etc., after winter storage. Brake pedal has always been firm but never really felt like good stopping power. No noticeable rotor warpage, pads appear to have plenty material left. Dry, empty backroad today. Ambient temps a hair above freezing. Several maximum-effort (think both feet on the pedal!) stops from 70-90 MPH. Enough to get them stinky-hot, but no noticeable fade. It stops, but not quite hard enough to get any tire squeak, let alone invoke ABS. I did read the various comments about condensation/water collection, bad M/C seals, etc. over time. So, I suspect the booster.
Anyone care to comment further?

[Adpros]

Is the supply line to the booster kink free? And is the check valve working? Just two thoughts to ponder.

[mirada6.0]

Not yet I just read through the FSM booster test procedure, so I'll do that tomorrow, as well as your suggestions, and post what I find. ( BTW, Mityvac's are very useful devices!!! If anyone doesn't have one it should be on top of the to-do list)

[mirada6.0]

OK, did the booster function test as per the FSM. It checks good. Everything is vacuum-tight. There is no evidence of brake fluid or water leakage at the MC-booster interface, it's clean and dry. I did notice that, when the pedal is pumped up while engine is off (to dump any residual vacuum) it will pretty well sink to the floor upon restart if my foot is still maintaining light pedal pressure. FSM says this could be due to "booster run-out". Anyone familiar with that?

[Adpros]

I'm not familiar with that term however, I am more likely to suspect the master cylinder's fluid bypassing the piston. If the pedal pumps up hard after a few presses and falls away a little after starting, that would be considered normal for a vacuum boost system.

If the pedal continually drops while holding light pressure, that's not a good sign.

[mirada6.0]

OK, went through all 4. Rt front pads were worn badly, l/f were maybe 70% worn. The piston in the r/f caliper was pretty well all the way out and felt stuck. However, they both retracted OK when I replaced the front pads.. Slider pins were free, all the boots and seals good, and rotors were well within specs. Rear pads were maybe 25% worn. I bled the system, and now have a solid pedal, and better braking. But here's the thing - it still won't stop hard enough (on dry pavement) to invoke the ABS. I don't have super-sticky rubber either. Any comments?

[peva]

Maybe the pads need to wear in a bit to grip better. What type of pads did you put on?

If you have any more problems, might be a good idea to put new calipers on the front. I messed with the brakes for a couple of years on my '98 Concorde with minimum improvement, until, by process of elimination I narrowed it down to the calipers. Finally replaced both front calipers, and it has been great ever since.

[paintballdude05]

What does the pad contact area on the knuckle look like? As in, the pad slides? If you get any wear on those you're in for a hard time.


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[peva]

FWIW, if they *are* worn, the pad retractors will provide a new (and renewable) perfectly flat wear surface for the pad ears to slide on. They used to make flat wear bars that did the same thing (without the pad retraction - some people don't like the pad retractors because they can add a little lost brake pedal motion), but I don't know if they make those anymore.

If anyone's interested in the flat wear bars, I can problably find a Chrysler part number (again, not sure if they are still available). And NAPA sells the retractors now - I can also post a P/N for those. I can also post photos of both parts installed so you can see what we're talking about.

[paintballdude05]

I briefly tried to install the retractors on the rear brakes once, it didn't seem to work too well. Can they be made to work on the rears?

[Adpros]

They still make the OEM slides with the "S" shaped spring incorporated. I put a new set on the Special when I did the brakes. Dealers still have 'em.

[peva]

No, Stephan - there is no hardware like that to fit the rears.

True. Those are what I call the pad retractors (because that's what they do). Still not sure if the flat wear bars (no 'S' shape) are still available. IIRC, Chrysler would provide one or the other under the same part number at different times - no rhyme or reason that I could figure out. I only see the pad retractors anymore. NAPA UP 83861 - set of four (does both front wheels).

Wear bar in upper photo. Pad retractor in lower photo:

[Adpros]

Now that I see the picture, I'd say it looks more like a "W".

[peva]

That's how some people describe them.

[mirada6.0]

Thanks for those postings - answered a few questions for me. Particularly Peva's pix. I really didn't figure out what the "wear bars" were, since they fell out immediately upon unbolting the caliper, and they are not shown in the 2000 FSM. The retractor springs are shown but apparently are omitted from the "export" brake package, which is otherwise identical as far as the manual. And my car didn't have them anyway.
I used Raybestos "service grade" semi-metallics, mainly because I'm cheap, and also because I'm easy on brake and clutch linings. I considered the ceramic but couldn't find any anecdotal evidence of improved braking, only less dust.
I wondered about the caliper as it doesn't appear to be much changed from the ones on the old Mirada, but that car would lock up the 255-15 fronts if desired. Stopped quite well with 11.75 cop rotors. Both cars are close in weight as well, so I wonder if my calipers have indeed degraded in efficiency.As for bedding in the new pads, I did a short (1 mile) uphill/downhill run and made several increasingly hard stops. That has worked for me in the past. There was a bit of hot lining smell after but that's what I expected.
I'll be headed to Vancouver next week, and that involves up and over the Cascades with lots of switchbacks and elevation changes for 60 miles. That'll tell the tale, I guess.