Idiler pullys on the duramax

[brooksider]

Well 2000 miles after replacing the head gaskets, the old duramx spit out the serpintine belt. The cause was a siezed up idiler pulley. I pulled of all three of this am as the other two idiler bearing,s were also getting a bit growley.Replace them now and forget about them.Only a twenty minute job. Hope I can pick them up in the morning as well as a new belt.
Joe

[Tom S.]

Yup, the pulleys do go bad, and if you lose the belt, not only do you lose your power steering, you also lose your power brakes! Been there, done that, not much fun.

[Art-n-Marge]

Uh, power brakes? I didn't know my brakes would be affected by a bad belt. I don't recall the booster needing a belt. IIRC, this wasn't true on other vehicles I owned. I better go look again. Last I looked the belt affected steering, A/C, water pump, alternator and fan. Now, the brakes, too? I also don't remember last time I replaced the belt as maintenance. I have over 90,000 miles on my TV.

[Alwims]

POWER BRAKES CONTROLLED BY A BELT!!!! Who in Detroit came up with that stupid idea?????? Surely you're not serious??????

[8.1al]

GM has done that for years on heavy duty trucks. The brakes have hydraulic boost rather than vacuum. This may not apply to turbocharged engines but wit normally aspirated ones the vacuum can get low during a hard pull such as a steep grade and the vacuum brakes don't work well, thus the hydraulic booster. The hydraulic system will retain some assist for a pedal push or two just like vacuum brakes. From what I can find on the internet it looks as though Ford and Chrysler also use it on their diesel powered trucks.
http://www.brakeandfrontend.com/issu...ontentid=38431

[Alwims]

Wow, learned something new today.

[8.1al]

If we quit learning we're in trouble.

[brooksider]

Got it fixed this am. Took about 35 minutes. That is right that you lose the power brakes. diesels do not provide a means of vacum so in GM 's case it is provide through the Pwr. sterring pump. Not sure what the others use.
Listenning to the engine now I would have to say that I had a growly bearing for a few days, but put the noise down to cold weather. Know better now.
Joe

[bigskyjimmy]

brooksider ,it only took 35 min to do the idlers and belt? Wow I'm going to do it to mine today ,I'm retired and it will give me an excuse to get out and do something, while I'm at it I will do the thermostats

[brooksider]

If you got small hands it will not take as long. Remove the top idiler, then the tension assembly and the bottom idiler, assemble in reverse order. I replaced thermostats when I had the Head gaskets done.
Joe

[bigskyjimmy]

Bummer! I have Herman Munster hands, sounds like it will take a little longer maybee a 3 beer job

[Devildog]

Power steering pump also feeds the brake booster. Follow your hoses off of your power steering pump and you will see. Lose a belt, or power to the engine, you will need both feet on the pedal to stop and it will be scary!