4wd vacuum hoses

[FredDog01]

94 yj sport 4 cyl
Newbe question, for my 4wd I can only see 2 vacuum hoses & 2 wires going to what looks like a large diaphragm. 1 goes to the engine the 2nd just hangs next too the battery (looks like a black check valve attached to the end of hose). Does this hose connect to anything else or just a vent?
Is an original axle setup or something the PO added ?
I figure the only dumb questions are the ones you don't ask.
Thanks Stan

 

[JPNinPA]

Oops you did say for 4wd. One thick hose from the pumpkin goes up align the firewall and stops into a plastic valve.. It is a breather vent. The other is a vac line I'll post a pic soon

 

[FredDog01]

Thanks. That looks like what I have. Will try to post pics later .

 

[FredDog01]

Does this look right?

 

[FredDog01]

more

 

[FredDog01]

Only found one hose on pumpkin that looks like a vent hose

 

[Bounty__Hunter]

Sounds like your system is original. The 4wd light switch is on your axle disconnect system, that's the electrical wires. Two black vacuum lines to the front axle shifts the 4wd disconnect. The vacuum tube beneath the battery is just a vent. The 4th line should be red and is source vacuum from the intake manifold to the transfer case switch.

Is your 4wd light working and the 4wd working okay?

 

[FredDog01]

I can't tell if the lights work or not the PO took the bulbs & holders out. How do you test 4wd on dry pavement or do I have to find a gravel road?

 

[Bounty__Hunter]

You can test it on dry pavement but it's not recommended. In 4hi or 4lo at a slow speed, turn tight and you'll feel the steering wheel pull side to side if 4wd is working. This is the system binding up and you don't want to do it for long.

Best to find gravel and have someone watch for the front tires spinning.

 

[FredDog01]

thanks