sounds like the system is not allowing fluid to return to the master cylinder. this is norm an issue with the rubber hoses going to/from the calipers or intenal corrosion of the hard lines clogging the master cyl/bias valve. with the amount of over heating you have i would take a hard look at the hoses again and think of blowing out the hard lines running between the master and wheel. do replace and bleed the fluid again, i'm sure you have boiled the fluid at least once (creating air pockets).

another thought, the abs system could be "on" for some odd reason and not letting the pressure out of the system. should be on it's own fuse, could try pulling it and see what's up.

 

he has no abs!
same care as mine! i have noticed that my 98 stratus 2.4 4door is realy hard on front brakes and rotors! as they have crappy drums in the back!

 

interesting problem. first off i don't know anything about a stratus, including what it looks like, so i might make a fool out of myself.

it sounds like you've already changed out all the normal stuff.
with disk brakes, the clearance between pads and rotors is very very little. so make sure the slide pins/bolts are clean and lubed and not binding. it sounds like you've done that, but if the pins are rough or corroded, replace them.

brake lines. brake line problems are generally where they leak, or are rusted up, and blocked, and brakes don't work. if you can bleed the brakes ok, the lines are probably ok. if in doubt, you could blow them out with an air hose.

master cylinder. already changed.

proportioning valve, vacuum brake booster, ABS system. could something be going on here ? where pressure is getting to the caliper, but never releasing ?

heat. you said this problem increased with time/heat. could the previous owner have run new lines too close to exhaust ? brake fluid getting hot ?

front wheel drive ? anything related to that ?

sorry no definite answers. i would try to put it up on jack stands and simulate driving, and try to duplicate the lock up. otherwise, i'd just keep replacing stuff not already replaced. i might replace the proportioning valve next, buts that's just a shot in the dark.

 

yep, bad call on the abs. looking through the haynes, the master cyl splits the brake sys into the left and right side of the car, not front to rear. the bias/proportioning valve is the only other thing i can think of that could cause your issue. let us know what you find.

 

Thanks for all the input. I had to go out of town for a few days (rented a car!) so I can't wait to get home (saturday night) and try these suggestions out. I haven't touched the rear yet, if there are problems there (I haven't dettected any) could that affect the front?

 

screwed up yet again.

"the hyd sys consists of two seperarate circuts that are diagonally split. one for the left front and right rear...", 2nd for the other two. they are split at the master cyl. "a dual proportioning valve on the firewall (coupe) or front crossmember (sedan) provides brake balance between the front and rear brakes."

so, yes it is possable that the rear brakes may also have issues and effect the front. the one issue is the system not releasing pressure back to the master cyl. i would still look to the front as this seems to be the issue. go cheapest first. flush your entire system till you get clean fluid out, keeping in mind the corrosion you spoke of might be the issue.

this is how i would go about it. by the cheapest brake fluid you can find in the biggest bottle, discon the hose going to your caliper and drop the hose in to the bottle of cheap fluid (empty it about halfway). so as not to let too much air in the system. start pumping the brakes keeping an eye in the fluid level. put good type fluid in the master cyl as you flush the front side of the bake system. the bottle of cheap stuff might spill over. this keeps any junk for going into the calipers and hopefully flushing out any corrosion that may be in the proprotioning valve (not sure the $$ of a new one). hope this helps.

 

Before I dive into this again tomorrow, I have a few questions. Seems like all I have left on the front is the metal lines, wich I will blow out. (Not sure how, I don't have a compressor - how much pressure does a can of compressed air produce?) The brakes seem to bleed just fine. Still seems logical to at least try and blow the lines out. The first time I bleed the brakes, the fluid was pretty bad. Comes out pretty clean on the front now. I thought that if the proportioning valves went out, I would likely have unwanted braking in the rear, not the front? If I try the idea of putting the car on blocks and testing the brakes there, I wonder if I can really get the brakes hot enough? I am sure they will heat up some from stopping the spinning wheels, but there won't be the weight of the car...

I was aware of the brakes working in pairs (rt front + left rear, left front + rt rear) and wondered if say a flow or pressure problem in the rear could be the source. I bleed the rear after putting in the master cylinder, but haven't changed anything yet. Changing pads, hoses and springs in the rear (no drums) would only run about $110 more, so I guess I can try that next. I am assuming that even if the corrosion is so bad that the drums are bad now, that wouldn't effect front braking too much, but that a problem with the hoses in the rear could. If it comes to put in new lines, I have a problem. No one around here sells pieces longer that 4 feet.

 

I have been wondering about another potential issue. Is it possible that I have warped the rotors due to the high heat? How do you know if the rotors are warped without the right tools to check them?

 

OK, I put the car on blocks and fired it up. The left front was dragging right away. I released a little pressure via the caliper bleeding valve, and now it spins freely, even at speed. The right front is dragging all the time. Bleeding it a bit offers partial, but not full release. It was dragging from the moment I started the car and applied the brakes once. Not quit sure if I should be using the term sticking or dragging, sorry!

 

Problem solved! When the car was ob blocks, I figured out that the brake pedal was not coming all the way up! Pulled the master cylinder out and made an adjustment, and all is good. Thanks for all the input. Still not sure how all this got started.