Vacuum problem

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BlackHole XJ

NAXJA Forum User

Location

Lexington, KY

• Dec 2, 2006

• #1

I have an 87 XJ 6cyl, 4L with a vacuum problem on the front end. The pin that slides to lock the front wheels in 4 wheel drive is not working. If proper vacuum pressure is applied the wheels will lock. I haven’t been able to figure out if the lines are correct. The diagram that I have is different from the setup on my Jeep. It could be that the vacuum switch on the transfer case is bad. Does anyone know how to check this without replacing the switch? I have been told that some people have rigged the front wheel lock to work manually with a bicycle hand brake. Does anyone have any information on that as well? Any suggestions would be helpful.

 

langer1

NAXJA Forum User

Location

Mineral City,Ohio

• Dec 2, 2006

• #2

Well the switch only turns the 4wd light on, nothing more.
Or are you asking about the vacuum valve on the t-case?

Most often cause though is a vacuum line that split, the one going to the vacuum receiver in the front bumper.

 

Last edited: Dec 2, 2006

C

csr_011

NAXJA Forum User

Location

Lincoln, NE

• Dec 2, 2006

• #3

The cause of mine to not lock out years ago was a $15 two vacuum line part off the actuator on the axle.

Cory

 

Matthew Currie

NAXJA Member #760

Location

Vermont, land of big clay

• Dec 2, 2006

• #4

I don't know any good way to check the vacuum switch on the TC, but it's pretty inexpensive - something under 20 bucks last I saw. If possible, though, it would be useful to get a vacuum gauge on the system and see if it's holding vacuum. As Langer points out, it's often a leak in the reservoir or the line going to it (check under the battery where corrosion often eats holes).

 

B

BlackHole XJ

NAXJA Forum User

Location

Lexington, KY

• Dec 6, 2006

• #5

Back in 4 wd. Thanks for the replys. Mystery has been solved. It appears that one of the vacuum lines was missing. Guess it just fell off somewhere. My light is now on and the front wheels are locking.

 

M

Monkey55

NAXJA Forum User

Location

SoCal

• Dec 6, 2006

• #6

I just got done replacing my vaccum bottle, but still have a leak somewhere.

Anyone know how to find the leak in the lines??

Elias

 

stewie

NAXJA Forum User

Location

the Union of Socialist States, Amerika

• Dec 6, 2006

• #7

feel the lines with your hand looking for nicks, cuts, breaks for air being sucked in. if you find a leak, you can repair it with duct tape, electrical tape, silicone adhesive/selant, a patch or a new line. the pressure isnt that high so tape seems to work pretty well.

hth

 

Ecomike

NAXJA# 2091

NAXJA Member

Location

MilkyWay Galaxy

• Dec 7, 2006

• #8

stewie said:

feel the lines with your hand looking for nicks, cuts, breaks for air being sucked in. if you find a leak, you can repair it with duct tape, electrical tape, silicone adhesive/selant, a patch or a new line. the pressure isnt that high so tape seems to work pretty well.

hth

Click to expand...

Did I hear someone say DUCT TAPE????
I love the stuff!

"Duct Tape is like the Force!!!! It has a light and a dark side, and it holds the universe together"!:cheers:

Author unknown.