The job at a glance
- Tools: A floor or other jack, jack stands, 8 and 15mm sockets, ratchet, pry tool
- Parts: None
- Materials: Silicone .
- Cost of parts: None
- Time: 1 hour
Checking Operation
The first notice that there was a problem was the failure of the 4wd light on the dash to come on after shifting. But I was troubled by the question "was it really not working?" So I jacked up all four wheels and put it in 4 wheel. The front wheels did not turn in 4wd.
Another way to check operation is to have a look at the vacuum actuator under the front of tbe truck.
1) Jack up the front of the truck and set on stands.
2) Remove the cover from the actuator. Three 10mm bolts.
3) Start the truck and leave in park. Note the relative position of the actuator. It will be to the right.
4) Place the truck in 4wd. The actuator should move to the left. Mine did not move.
Another way to check operation is to have a look at the vacuum actuator under the front of tbe truck.
1) Jack up the front of the truck and set on stands.
2) Remove the cover from the actuator. Three 10mm bolts.
3) Start the truck and leave in park. Note the relative position of the actuator. It will be to the right.
4) Place the truck in 4wd. The actuator should move to the left. Mine did not move.
Checking for vacuum
Since vacuum plays such is such a big part in the show, I took a look early in troubleshooting. I opened up a line feeding one of the solenoids. Only the front of the truck needs to be up.
2) Pull the vacuum lines out of the solenoids. The lower of the two is the supply.
3) Start the truck and check for vacuum. It should always be there, in four wheel or not. With the truck running, it wasn't there.
Now we have to backtrack to find where the vacuum is and is not. We are going to look for, and inspect, the vacuum reservoir box.
4) Disconnect and remove the battery.
5) Unbolt and remove the battery box. (four 15mm bolts).
6) Separate a wiring harness from the box with a prying tool.
7) The smaller of the two reservoirs is for 4wd. Remove the supply line from it and check for vacuum here. It was present.
I thoroughly inspected this box and could find no crack. I put some low pressure compressed air into it and looked for air bubbles with a dish soap and water mixture. Once, I think I may have seen a bubble. It was that indefinite. I applied silicone to all the all the seams on the box as a simple remedy..
5) Unbolt and remove the battery box. (four 15mm bolts).
6) Separate a wiring harness from the box with a prying tool.
7) The smaller of the two reservoirs is for 4wd. Remove the supply line from it and check for vacuum here. It was present.
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The 4wd vacuum reservoir |
I thoroughly inspected this box and could find no crack. I put some low pressure compressed air into it and looked for air bubbles with a dish soap and water mixture. Once, I think I may have seen a bubble. It was that indefinite. I applied silicone to all the all the seams on the box as a simple remedy..
Testing
Hook the battery back up, without mounting, and test again for vacuum. It was now there at the inputs to the solenoid.
Reassembly
1) Mount the battery box.
2) Snap the reservoirs back together and into mounting position.
3) Mount and connect the battery.
4) Plug the vacuum lines back into the solenoids.
5) Plug the electrical connectors into the solenoids.
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