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Discussion Starter · #1 ·
I haven't had 4wd for a while due to no vaccuum. I just replaced the vaccuum switch behind the aircleaner, still no vaccuum. What would be causing this. I took off the vaccuum harness at the front axle to check for any vaccuum in at least one of the hoses. NOTHING!!!! . I don't know why I am getting no vaccuum. Someone please help me. I hate having a Jeep without 4wd.
HELP
BEEE240
88 Wrangler 4.2 5 spd.w/ac and crappy Carter BBD.

 

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Re: No vaccuum...

Check the vacuum at the transfer case. That is where it switches from one line to the axle to the other. You need vacuum to the front axle shift motor in both 2wd and 4wd. Good Luck!! /wwwthreads_images/icons/smile.gif
 

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Re: No vaccuum...

If there is no vacuum at the transfer case, you'll have to trace the vacuum supply line back to see where it is broken or kinked.

Maybe a dumb question but you are checking for vacuum while the engine is running, right?/wwwthreads_images/icons/smile.gif
 

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Re: No vaccuum...

If you checked your electric vacuum supply unit on the fire wall and it pulls a vacuum (I guess you used a guage to check it and got a reading) and you have no vacuum at the end of the line, either at the t-case or front diff, then there must be a crack in the line somewhere. I broke one of mine lines on top of the t-case before, they are pretty brittle. I just used some vacuum hose to join the two plastic pieces.

/wwwthreads_images/icons/cool.gif Big Ed
'88 YJ, 4" susp,3" body,33's,283 Chevy V8,TH350,4.11's,D30,D35c
 

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Discussion Starter · #6 ·
Re: No vaccuum...

Actually I bought a new vacuum harness for the 4wd. I have four little "nozzles" coming out of the top of the tcase and what seem like two from the side of the tcase. The top one(of the two on the side; I have the harness on the top of the tcase hooked up already) is hooked up to some line, but the one just below it isn't hooked to anything. Does anyone know what these are and where they go? I can't seem to find a picture of a tcase(for a stock 88 w/ a 4.2 man. anywhere). It would be very helpful if someone knows where I can also get a picture of one intact with all of the vaccum lines hooked up.
My last ditch effort before putting it in the shop.
b./wwwthreads_images/icons/frown.gif
 

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Re: No vaccuum...

Sorry beee but I have a Cherokee and am not familiar with how the vac lines run exactly on your Wrangler. I, too, have no luck finding a good diagram of how the lines run from the t'case. I do know there is supposed to be vacuum to the front axle any time the engine is running regardless if the transfer case is in 2wd or 4wd. To me that means it makes no sense for the vacuum supply to the transfer case to be switched or go thru a solenoid. To my way of thinking there has to be something wrong with the line that comes from the engine compartment to the case, either it's broken or clogged.

Do you get vacuum from any of those nozzles you described? Good Luck!!/wwwthreads_images/icons/smile.gif
 
G

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LISTEN I HAD THE SAME PROBLEM WHEN I FIRST BOUGHT MY 87YJ. MY VACUUM LINES LOOKES LIKE SUNDAY'S SPAGHETTI. THERE IS A SMALL VACUUM CANISTER LOCATER UNDER THE PASSENGER FENDER ( SMALL BLACK BALL ) MY LINE HAD LOOSENED AND FALLEN OUT BEFORE I BOUGHT MY JEEP. I KNOW IT SEEMS SMALL AND INSIGNIFICANT BUT CHECK THE CANISTER ,GOOD LUCK!

 
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