I have a 1991 s10 blazer. In my attempt to fill my power steering fluid i put a little in the brake fluid reservoir. Stupid, I know. This led to the complete decimation of my brake system. I decided to replace the whole system myself. I put in a new master cylinder, calipers, wheel cylinders, pads, hoses, and then flushed about 2 liters of new fluid through the system. I now have stopping power but for some reason the front disks are heating up and smoking after the short test ride i made. Did I forget something? I know Ive made progress because I went from having no stopping power to what feels like normal brake function. Do I need to replace the hubs and bearings or something? PLEASE HELP!

 

Are your rear brakes getting warm or are the front brakes doing all the work?

If you jack the front wheels off the ground are the pads sticking or can you spin the front tires?

 

Thanks for the reply. Only the front brakes are getting hot and I mean really hot. The air stem cap on the passenger side partially melted. Ill try spinning the tires in the next few days and give you an answer. Im trying to fit working on this between school and work. Its been hard to focus on anything but getting my truck fixed. I love that thing. Again thanks for the fast reply.

 

I would do what chevy lover said and also did you lubricate your slides on the caliper's? That would cause sticking as well!!

 

If its getting hot you have a caliper that is hanging up. Did you twist the brake line when you replaced it. Look at the ribs on the line, if they make a circle or half circle you need to fix it. Twist in teh line will cause it to close on the inside.

Did you spray all the rotors and brake shoes with brake cleaner?
New rotors have a oil film on them to prevent them from rusting in the box. That oil will play havic with your brakes and smoke like a biotch.

I didn't look, however if you have a 2wdr it is possible that oyu have a bearing going out. If you have a 4x4 you may have a hub assemble going out. Both are easy enough to fix/replace, however the 4x4 version is not cheap.

 

Ok. I just got to jacking the car up to see if the front tires spin and they do. I pumped the brakes a few times to make sure they weren't sticking and they didnt seem to be. When I spun the wheels there was a slight grinding sound but nothing that seemed to be hindering the ease of the wheels spinning. So, that means Im not getting heat from the friction of the pads right? What else would cause the damn things to heat up so much? I have a 4x4 so im guessing it could be the hub assembly. Would a problem be visibly noticeable if the hub assembly needed replacement? I didnt mention before but my brake indicator light on the dash is always on now too. Thats were Im at.

 

I just did a little round the block drive and the rotors were hot. It has to be the pads grinding that slight amount thats creating the heat. Would bad hubs heat up so fast only going 1 block at 10mph? Im losing my mind. I need my truck back!

 

Brake light on means you have a brake problem, typically a leak or low brake fluid. Low brake fluid due to leak, or worn out pads, front or back.

Light grinding could be the pads, or it could be wheel bearings, however generally with wheel bearing you wont hear it whille the tire is off the ground. Plus its more pronouced in turns at first, after a while even going straight it grinds.

To me it sound like you have a caliper hanging up, not sliding all the way back when your take your foot of the brake peddle, thus heating up your rotor. How many rotors are getting hot and which one?

If its both fronts or both rears, then you may have a problem with the proportioning valve or some other common brake part, master maybe. If it sjust one side, take that caliper off and check for rust, grease. Take them pins out and look for corrosion. If the pins are not smooth as glass, replace them. Dont buff them out on teh bench top grinder. There is a protective coating on them that helps with the grease and slippage. Remove that coating and they will fail in no time.

Another possbilitiy is warped rotors, however you didnt say anythinga bout vibrations when braking. Or pulling while braking.

 

Just an update. I really only have an hour here and there to try and fix this thing. Im 90% sure the proportioning valve is the root of my problem. When I looked to replace it I found out it would cost $300 because no one makesit after market.Needless to say I almost lost it seeing how Ive already spent over $400. The autoparts guy told me the valve wouldnt go bad from contamination but the plunger could get stuck on either side. He told me to try and bleed the PV. When I went to do it I found it really tough. This might sound dumb but does the engine need to be running when I bleed the system? I had it running when I did the calipers ect. but having it running and working under the hood dosn't seem like a smart idea. Will I still getcompressionwith it off?

 

You do not need to have the engine running to bleed the brakes.