Comanche/XJ help needed.

**JeepinSoldier** · 06-28-2009, 15:06

Got a welcome to the world of old Jeeps today.

Just picked up a 1990 Jeep Comanche a few weeks ago. When I got it the brake pedal was really soft and the front rotors and pads were visibly worn out. Today I replaced the front rotors and pads and flushed and bled the system. Got alot of dirty fluid out. The pedal still feels soft to about half of its travel and then the brakes are responsive. I can lock them up.

Is this soft pedal to halfway before the brakes starting to engage normal?

The positive and negative battery cables were both very corroded with visible wire showing, so I replaced them. While I was under the truck installing the positive cable to the starter, I noticed the vaccum connection to the front axle disconnect not connected and just hanging down loose.

When I connected it, the 'Part Time' light on the dash board inside came on even though the transfer case shifter is still in the 2 high position. Any idea what causes this?

There is also another vaccum line that comes from the firewall disconnected and I dont have any idea where it goes. There is an electrical wire attached to the top of the A/C compressor that is not attached to anything and just hanging down.

**bluedragon436** · 06-28-2009, 15:16

The second vacuum line sounds like it could be for a brake booster of some sorts, especially if you are having to real responsiveness to your pedal... And the connecter that is attached to the top of the AC compressor, is supposed to be hooked up to the AC compressor?? Does your AC work??

**Jeffb_79** · 06-28-2009, 16:18

I know on the 4.0 engines, the vacuum lines start at the drivers side intake manifold... branch off to the brake booster then snake off to the passenger side. There's a black sealed box about 2"x2"x5" that the line plugs in to. From there it passes through the passenger side fire wall and I believe heads in to the AC system.

**bluedragon436** · 06-28-2009, 17:10

Yeah that is what I was thinking, I was trying to find a diagram in the FSM I have, since my Jeep is currently at the shop!!

**Fred** · 06-28-2009, 17:34

rear brakes probable need replacing. Replace everything out back can be done cheap.

**JeepinSoldier** · 06-28-2009, 18:28

The disconnected vaccum line comes from the passenger side firewall just above the A/C lines. Its orange or mabe was originally red in color. Its pretty small and there is a small black vac line right next to it. I dont think its part of the brake system.

I can replace the rear pads and drums after payday.

I found a disconnected orange wire coming from a wiring harness near where it could connect to the wire coming from the A/C compressor - but as Im not positive that that is where it goes Im not connecting it.

Just found another disconnected electrical connector at the rear driver side of the engine.

The engine runs just fine. I guess it really does not need all these disconnected vac lines and wires LOL.

**Jeffb_79** · 06-28-2009, 18:43

I know in the wranglers they used a universal wiring kit... dig around under he hood of your rubicon and you'll probably find one or two connectors not hooked up to anything.

I still think for the loose vacuum on the passenger side... there's probably a small black box some in the engine bay passenger side that it'll plug in to.

**RescueJP** · 06-28-2009, 18:46

Does your ac blow out of just the defrosters.

**JeepinSoldier** · 06-28-2009, 18:57

Originally Posted by Jeffb_79

I know in the wranglers they used a universal wiring kit... dig around under he hood of your rubicon and you'll probably find one or two connectors not hooked up to anything.

I still think for the loose vacuum on the passenger side... there's probably a small black box some in the engine bay passenger side that it'll plug in to.

True. My LJ has the temp sensor and wiring harness for the rear view mirror installed - but has the rearview mirror without compass/temp so the harness is just there and not connected to anything.

The Comanche is the base model without cruise control and the dash has only a speedo and gas gauge with four idiot lights. The connector could be for cruise control or a tach. Or it could be for somthing important.