2004 4x4 vac problem

[DavidOH]

2004 s10 zr5. I've read every thread I can find on vac trouble without luck. I have grinding from the left front. The dash buttons say I'm in 2wd hi but the actuator is sucked in. It has vacuum on it all the time. The hubs seem OK but I'm going to pull the left to check the abs. I've backed up which helped a little. When I ran it with the wheels off the ground it would go in and out of 4wd but I heard no noise and the abs light was on and off I've disconnected the actuator to release it and plugged the line but the grinding got worse. I also pulled the line cap off the transfer switch. They are dry and this only let the actuator release a little.

I'm read that a number of things can cause this. I'm trying to avoid throwing parts at this. So I'm hoping someone can help me narrow this down.
I did find the idler arm was bad so changed that. Thanks

[zumina]

http://www.s-10crewcab.net/og1/modinfo/ ... witch.html
I dont know much but i found this. just trying to be a quick reply.

[HenryJ]

Yes, the transfercase switch would be a good place to start from those symptoms.

[DavidOH]

Thanks. Read that thread a few times. Going to try the tc-switch. It's cheap and I don't have a 36mm to get the front rotor off at the moment.

[HenryJ]

Look for fluid in the lines. That may indicate problems occurring farther up from the contamination.
Also check the lines behind the brake booster for dry rot. Make sure the line to the reservoir in the fender is connected while you are there.
Lots to inspect before replacing parts.

[DavidOH]

The line to the reservoir is dried out some will replace it and check others. Changed the t-case switch. Had to use my best tool. (cresent wrench) The old switch frozen. I do have some fluid in the line by the switch but not at the actuator or the reservoir. Will have to get to a compresser to clean that out. The actuator is now working. Should the it fully extend or only part way? What trouble can I have with the cable? The noise is still there. Can the cable cause this? If not I'll have to pull the rotor and look at the hub. There is no play in it with the wheel on.

[HenryJ]

Cruddy cables are not unusual. Might see if you can free it up and squirt some lubricant in there?

[DavidOH]

Forgot to update this. In hunting the cause of the noise I found the idler arm bad and the 4x4 actuator not working. (replaced arm and t-case switch) Still had the noise. Could not tell the hub was bad with tire on. With tire and rotor off still could not tell. Took the hub off so I could hold both sides and twist. Then I could feel it was bad. I had a new hub to put on just in case. The noise is now gone.

My thanks to this forum for all the info I found.

[HenryJ]

So now problems all solved?

[DavidOH]

For now they are. But in my hunt for the problem I found a few other things that are going to need done soon.

[HenryJ]

So in the end the noise was the wheel bearing? The 4x4 was a separate issue?