Archived hydroboost replacement, now alternator smoking hot

[TLanier]

Ill post everything i can think of that may be an issue, so someone with more brain cells than me can tell me what the heck is going on.



when i bought the truck last summer, i noticed that the brakes were funny. the hotter outside, the worse the problem. when i went to apply the brakes, the pedal gave alot of resistance, felt stiff, wasnt going thru the travel, and i wasnt slowing. then when i gave the pedal more push, all of a sudden the pedal depressed, the brakes kicked in hard, and the rear often locked up with a shuddering jolt. this didnt, and doesnt happen every time, but often.



both rotors were replaced, and pads, and drums checked. didnt help. abs sensor in the rear pumpkin (i have rear anti lock brakes) replaced too. one fellow told me to check the fluid in the power steering, that if it was red, it could be screwing up my hydroboost. sure enough, it was red, auto transmission fluid, not good for the hydroboost. figured that the brake prob was the valve in the hydroboost getting hung up then coming loose and hitting hard, due to the fluid. . guy before me had been running crap. i flushed it out, and put in valvoline power steering fluid.



still did it, so i figured it had already damaged the hydroboost, and to replace that.



fast forward to today. ive been living with the problem, and decided to change the hydroboost. got a remanufactured one at napa, put it on, flushed the old fluid, put in new fluid, started and stoped the truck, turned the wheel back and forth, checked level, added more, repeat, until all was well.



i went for a test drive. the brake application seemed smoother. then... ... it did it again, albeit with less force. it was better, but the prob was not gone. prob still there. i was really ****** i spent $260 and didnt fix the prob.



then, the abs and brake light came on as i was driving. next, i saw smoke coming from under the hood. i was just a few blocks from home so i got back to my driveway. when i opened the hood, there was smoke coming out of the alternator, and it was really hot. i checked the alternator fuse and the abs fuse and both were good. my voltage was still reading 14v in the dash. the batteries were not hot, nor the cables. and i didnt spill any fluid near the alternator, so thats not it.



next i noticed that the brake lights in the tail were on, but the pedal was not depressed ( i was out of the truck) and the key was out. i checked the brake switch at the brake pedal lever and sure enough there was no contact between the brake lever and the switch. apparently, there were slight differences between the old and new hydroboost unit, and now the switch no longer made contact. i had been driving around with the brake lights on. this must have tripped the abs and brake light im guessing. but why was my alternator smoking?



i elongated the holes in the brake switch bracket, and moved it so i got brake light on/off function. then i drove the truck around the block again. the abs and brake light were not on anymore. so far so good. then, i noticed the smoke coming from the alternator again. #@&$##!!!!!!!!



im at a loss. just yesterday, i cleaned all my battery terminals. they had become coroded and the batteries had died. after i cleaned them, i checked each battery independently, and each had same voltage. i checked the alternator when engine running and no batteries hooked up, and it was putting out 13. 6 volts, seemed fine. hooked all back up and truck started up fast as lightning again. alternator was fine.



what in the world is wrong with my truck?



1)why are the brakes sticking, then abruptly unsticking, and locking the rear brakes?



2)why did replacing the hydroboost not fix that, even though it got a little better?



3)why is my alternator smoking now



4)what does a stuck brake switch mean, would it cause my alternator smoking?



5) why, after i fixed the switch, would my abs and brake light go back off, but my alternator still smoke?



PLEASE SOMEONE HELP ME HERE!?!?!?!

 

[R C Cola]

What is the problem ?

Don't ya just hate when it does that, makes me want to chew nails. Sounds like you may now have the electrical problem solved, if not then... Lets try some basics. Have you made any changes recently (electrical) that may have caused a problem? Check each fuse in the fuse block carefully. Check all ground connections, especially battery and engine to frame, clean and tight. Remove the alternator belt and turn by hand, should turn easy and with no noise or felt roughness. Many auto parts stores (checker, Autozone, etc. ) will do an in car test of battery and alternator, they will bench test after you take it off. I reccomend both (finds differant problems). I beleive there is a sensor on the rear axle that can be cleaned or replaced but, I still have trouble with my brakes so I will let some more knowledgeable tackle that one. Good Luck... . RC

 

[TLanier]

well, why would the alternator still smoke if the electrical problem (brake light switch) is fixed? i cant drive the thing now! i mean, why did it smoke to begin with? has it been fried, so now it keeps smoking?



sensor in the rear axle was replaced last summer.



have not taken the belt off alternator and turned by hand... . will check that in morning.



just cleaned all batt terminals and tightened, and checked each batt separately and alternator, all read fine by my multimeter, yesterday, before this job.



and, why are my brakes still doing that crap after changing the hydroboost?

 

[R C Cola]

Why broke?

Spin by hand will tell if bearings are rough or tight, should spin free w/no roughness and quiet. Bad bearings will overheat a lot just before they seize up.

Then take out and have a bench test done, most autoparts stores do this free.

Will find any type of internal circuitry problem. While the belt is off it is a good

idea to spin the waterpump bearing and the idler bearing to be sure they are O K

This can be done while still on the truck.

 

[R C Cola]

Running test

With the truck running and all hooked up the voltage at the battery terminals

should not be over 16v, any higher and there may be an external demand somewhere on the truck wanting more power ( short or etc. ) With the motor turned off voltage at the battery should be about 12. 7v RC

 

[Bfoot17]

I would first check the bearings in the alt, as RC said, with the belt off make sure it rotates fine and smooth. Then check it with the truck running for out put voltage, and increase the load on the alt by turning on the lights, a/c, etc. Anyway to increase the load on the alternator and to make sure the ecm is charge the batterys back up. The ecm is the voltage regulator on these trucks it also use a battery temp sensor to control the rate of charge as well.



About the brake problem... I am assuming that the power steering is still doing a good job. Does only the rear brakes look up not the front?

 

[bmoeller]

What about the ABS pump and the accumulator? A bad accumulator can cause a hard pedal.

 

[R C Cola]

brakes

B Moeller . . I'm ignorant of the accumulator and the ABS pump, what is ?

I also have brake problems. R C

 

[TLanier]

well, its fixed i think

sunday i went back and drove the truck after it sat all night. i pumped the accumulator on the hydroboost a few more times and turned the wheel back and forth to bleed out any air. that seemed to help alot, as the brakes worked really smoothly, and no lock up or funny catch-and-release prob. hope that lasts. could just have been a combo of the old hydroboost fouled up by the red AT fluid, and air in the system.





as for the alternator, it didnt smoke. at all. i took off the belt, and it spins great, like butter. batts with truck off read 12+ volts, with running system reads 13. 5 volts. seems fine. i dont see how it happened, cuz the alternator is way away from where i was working, but i MUST have somehow dropped some PS fluid on the alternator, and it was burning that. It was such a coincidental occurance, that it happened at the same time the brake switch stayed on with the new hydroboost brake pedal link, and the abs light coming on because of this, i thought sure the alternator smoke was related.



seems it wasnt.



i drilled out the holes in the brake switch bracket, so now it contacts and releases as it should. abs light off. brake light off.



the power steering has always and still does work fine. the prob has always been the rear brakes only locking up. but the fronts wont lock up, due to the weight. i think it was indeed the hydroboost.



have not checked the abs pump or accumulator.



thanks for all the help.