Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here XJ (84-01)
All OEM related XJ specific tech. Examples, no start, general maintenance or anything that's stock.

Oil Pressure Sending Unit removal question

Thread Tools
 
Search this Thread
 
Old 02-08-2016, 04:03 PM
  #1  
Junior Member
Thread Starter
 
L2daGee's Avatar
 
Join Date: Jan 2016
Location: San Antonio, TX
Posts: 56
Likes: 0
Received 0 Likes on 0 Posts
Year: 1999
Model: Cherokee
Engine: 4.0
Default Oil Pressure Sending Unit removal question

My oil pressure gauge seems to be malfunctioning. I understand that I should use a mechanical gauge to make sure the pressure is where it's supposed to be.

I've borrowed a pressure gauge, and now it's time to remove the oil pressure sending unit, however I can't seem to remove the electrical connection. It just seems to be stuck on there.

I don't see any sort of clip to press or remove. Is there some sort of trick? Or does it just require a firm pull? I don't want to break anything. Any suggestions would be greatly appreciated. Thanks in advance.
Old 02-08-2016, 04:42 PM
  #2  
CF Veteran
 
robertj's Avatar
 
Join Date: Nov 2008
Location: Herndon, VA
Posts: 1,077
Received 21 Likes on 18 Posts
Year: 1996
Model: Cherokee
Engine: 4.0
Default

There's a clip that you have to push down on. It's there, keep looking. It does take a little force sometimes.
Old 02-08-2016, 06:23 PM
  #3  
Junior Member
 
nakosd's Avatar
 
Join Date: Mar 2013
Posts: 48
Likes: 0
Received 0 Likes on 0 Posts
Model: Cherokee
Default

On mine (2000 xj) I believe there was a red locking tab that you need to pull/push in one direction to unlock it, and then typically with those clips you squeeze one part of it and it should disconnect, but they usually require a decent tug.

You should be able to rotate the sending unit by turning the brass hex fitting with a wrench, which should show you the other side of it, shouldn't be a big deal on the wire as long as you don't twist it too much.
Old 02-08-2016, 06:32 PM
  #4  
Junior Member
Thread Starter
 
L2daGee's Avatar
 
Join Date: Jan 2016
Location: San Antonio, TX
Posts: 56
Likes: 0
Received 0 Likes on 0 Posts
Year: 1999
Model: Cherokee
Engine: 4.0
Default

I was able to get the wiring harness off, although mine was missing the red locking clip.

I then noticed that oil is leaking from the sending unit and the wiring harness has oil on the electrical contacts. Any suggestions on how to clean it? I'm thinking of just using electrical contact cleaner.
Old 02-08-2016, 06:38 PM
  #5  
Junior Member
 
nakosd's Avatar
 
Join Date: Mar 2013
Posts: 48
Likes: 0
Received 0 Likes on 0 Posts
Model: Cherokee
Default

I would try using cue-tips or cleanex or paper towels to absorb and wipe up the oil, i wouldn't try spraying any sort of cleaning solution on it.
Old 02-08-2016, 07:04 PM
  #6  
Junior Member
Thread Starter
 
L2daGee's Avatar
 
Join Date: Jan 2016
Location: San Antonio, TX
Posts: 56
Likes: 0
Received 0 Likes on 0 Posts
Year: 1999
Model: Cherokee
Engine: 4.0
Default

Originally Posted by nakosd
I would try using cue-tips or cleanex or paper towels to absorb and wipe up the oil, i wouldn't try spraying any sort of cleaning solution on it.
Thanks. I will try that first. I went ahead and ordered a replacement Mopar oil sending pressure unit since I noticed the old one was leaking. I will hook up the mechanical pressure gauge tomorrow to verify I have correct pressure while I wait for the part to arrive.
Old 02-08-2016, 07:38 PM
  #7  
Junior Member
 
AbbadonTD's Avatar
 
Join Date: Jan 2013
Location: Colorado
Posts: 95
Likes: 0
Received 0 Likes on 0 Posts
Year: 1998
Model: Cherokee
Engine: 4.0 I6
Default

They leak. The trick that you can rotate the fitting above is how to get to it.

Isopropyl alcohol is always fine for these kinds of electronics cleaning.
Old 02-09-2016, 06:08 AM
  #8  
CF Veteran
 
CCKen's Avatar
 
Join Date: Aug 2010
Location: Canton, MI
Posts: 8,357
Likes: 0
Received 82 Likes on 67 Posts
Year: 1999
Model: Cherokee
Engine: 4.0
Default

Originally Posted by L2daGee
I was able to get the wiring harness off, although mine was missing the red locking clip.

I then noticed that oil is leaking from the sending unit and the wiring harness has oil on the electrical contacts. Any suggestions on how to clean it? I'm thinking of just using electrical contact cleaner.

Get a spay can of CRC QD Electronic Cleaner from an auto parts store and use it. It won't damage plastic like Alcohol or other cleaners.
Old 02-09-2016, 02:20 PM
  #9  
CF Veteran
 
Ralph77's Avatar
 
Join Date: Oct 2015
Posts: 7,357
Likes: 0
Received 1,531 Likes on 1,173 Posts
Year: 2000
Model: Cherokee (XJ)
Default

Originally Posted by CCKen
Get a spay can of CRC QD Electronic Cleaner from an auto parts store and use it. It won't damage plastic like Alcohol or other cleaners.
Agreed. Works good. Cleaned all my injector connectors when I upgraded to 4 hole ones. Little pricey but the stuff to buy.
Old 02-10-2016, 07:33 PM
  #10  
Junior Member
Thread Starter
 
L2daGee's Avatar
 
Join Date: Jan 2016
Location: San Antonio, TX
Posts: 56
Likes: 0
Received 0 Likes on 0 Posts
Year: 1999
Model: Cherokee
Engine: 4.0
Default

Originally Posted by CCKen
Get a spay can of CRC QD Electronic Cleaner from an auto parts store and use it. It won't damage plastic like Alcohol or other cleaners.
Worked great. New OPSU installed and oil pressure readings are back to normal.
Old 02-11-2016, 02:57 PM
  #11  
CF Veteran
 
BlueRidgeMark's Avatar
 
Join Date: May 2012
Location: Lost in the wilds of Virginia
Posts: 7,964
Received 952 Likes on 767 Posts
Year: 1998 Classic (I'll get it running soon....) and 02 Grand
Model: Cherokee (XJ)
Engine: 4.0
Default

Originally Posted by AbbadonTD
Isopropyl alcohol is always fine for these kinds of electronics cleaning.
Isopropyl alcohol is always NOT fine for these kinds of electronics cleaning. Many circuit boards have materials that are affected by isopropyl alcohol.


Originally Posted by CCKen
Get a spay can of CRC QD Electronic Cleaner from an auto parts store and use it. It won't damage plastic like Alcohol or other cleaners.

Ken's advice is the correct advice.
Old 02-11-2016, 03:12 PM
  #12  
Junior Member
 
AbbadonTD's Avatar
 
Join Date: Jan 2013
Location: Colorado
Posts: 95
Likes: 0
Received 0 Likes on 0 Posts
Year: 1998
Model: Cherokee
Engine: 4.0 I6
Default

Word.

I figured he meant the ON engine device itself - just getting oil and crap off of there. Isopropyl wont seep into the cracks and hurt anything, itll dry up.
Old 02-11-2016, 09:07 PM
  #13  
CF Veteran
 
DFlintstone's Avatar
 
Join Date: Aug 2011
Location: Nor-Cal Coast
Posts: 10,489
Likes: 0
Received 17 Likes on 17 Posts
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Default

I use cheap Mall Wart starting fluid for allot of cleaning. Cuts and blasts away crud then evaporates pretty quick. But then I put bearing grease all over and in my battery connections, Dex III in my power steering and Castroil 30W in my engine, soapy water in my windshield squirter, LP in a tire in a pinch, and run propane in my AC as well. Go figure! All works fine since it's not nutty cold here.
Old 03-02-2017, 12:52 PM
  #14  
Newbie
 
Moto nerd's Avatar
 
Join Date: Aug 2014
Location: Knoxville, Iowa
Posts: 5
Likes: 0
Received 0 Likes on 0 Posts
Year: 2001
Model: Cherokee
Engine: 4.0
Default

What unit does everyone use? Just bought a 90 reads 0 on the gauge looking to replace the pressure unit and no auto parts store stocks it. Cheaper online anyways but I'm not sure what one to use. Part #? Please thanks guys.
Old 03-02-2017, 02:16 PM
  #15  
CF Veteran
 
DFlintstone's Avatar
 
Join Date: Aug 2011
Location: Nor-Cal Coast
Posts: 10,489
Likes: 0
Received 17 Likes on 17 Posts
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Default

The temp switch at the rear of the head that works a gauge? I did some searching at rockauto.com The one for a light is just a switch, where the one for a gauge is a variable resistor. They don't seem to clearly state what they are selling though! In the info on the $23 one they mention "variable resistor" though. I suppose you could call them. > http://www.rockauto.com/en/catalog/j...+/+sensor,4748


Quick Reply: Oil Pressure Sending Unit removal question



All times are GMT -5. The time now is 01:26 PM.