View Full Version : Need Help
02-08-2006, 12:29 AM
Well a while back my brake warning light in the dash came on in my 89F250. I blead the brakes and it turned off, so i didnt worrie about it. 1 week later it came back on, i did have any leaks and the brakes still worked the same so i just ignored it. Now 2 months later, "present tense", ive noticed the brakes just not workin like they used to. The rear shoes looked a little worn so i replaced them, no change. The ABS light had also come on so i cleand the sensor, no change so i replayced it yesturday. Blead the brakes at school again today, wanted to see if the week braking had anything to do with lack of fluid flow but the fluid came out flowing strong, and none of the lights shut off. I know the wheel cylinders are working properly because in the rain i can lock the rear tires up if i want to, but i still have a supision that the proportioning valve is shutting them off from time to time, because sometimes the brakes work reall good, like they should, but mostly their still weak. So i really dont know what to do but take it in and have it looked buy a "professional." Any help i could get would be nice. Thingk it would be worth while to throw in a new proportioning valve to see if tings inmprove????
I just dont know what to do now???
02-08-2006, 12:32 AM
hmm weird man, maybe low fluid?
02-08-2006, 01:12 PM
never heard of replacing p vavle they never seem to go sounds little like master is weak when the abs light comes on it means there is a problem in the abs side of the system not in the actual functioning of the basic brake system >>> is there a low fluid sensor in the master [cheers]
02-08-2006, 02:39 PM
Leaking piston in master cylinder will do that.
Sometimes it works fine sometimes not.
When it bypasses too much it travels to far and the brake warning light will come on.
Pump the pedal a few times and if the piston seals again the light goes out and your brakes come back.
This might also screw with your abs system as well.
02-08-2006, 11:54 PM
K thanks for all the help, i guess i know what im doing this weekend
02-12-2006, 12:32 PM
Ok so i put in a new master cylinder, bench blead it, pu tit on, followed all the recomended tips it cam with, blead the whole system, bla bla bla. The brakes work good when i took it around the block, but the brake waring\indicator light never shut off, nothingnew their, and the ABS light came on after one pump of the brakes. What am i doing wrong, how do i get these dam lights to go out, im gettin temped to just pull the bulb, but i want it to work so when something accualy does go wrong ill know.
I would take it in and have the pro's look at it sounds like you have done everything.
02-12-2006, 02:08 PM
Don't know if I'm on track here, but had a similar proble with a Bronco. Replaced the MC & it worked once good, then back to being shitty. Replaced the MC 3 more times with the same problem. Again took it back to NAPA & they were getting pissed about all these MC's I was bringing back, so they gave me another one to try. Got it home & took it apart before bench bleeding. The thing was full of machining fileings. Took it back & we pulled the others apart & yep full of crap! This doesn't explain the cause to your problem but maybe to the new MC not working.
02-12-2006, 06:08 PM
interesting, im gunna have my mechanics teacher take a look at it on tuesday, see if the 2 of us can come up with some more possible problems. Their might be a weird bleeding sequence or somethign, who knows, i might have to replace a few more sensors
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