Gain extra benefits by becoming a Supporting Member Click here find out how!

Classic Performance Products Nu-Relics Power Windows
American Auto Wire Hellwig Products IncPerformance Rod & Custom
Danchuk Catalog



Username Post: Oil pressure sensor leak - 1990 350 TBI PU        (Topic#365869)
Joe_W 
Silver Supporting Member
Posts: 93
Joe_W
Loc: rural upstate westernNY
Reg: 11-14-20
07-21-21 07:35 AM - Post#2823617    

Hello friends.
I'm attempting to remove a leaking oil pressure sensor that is leaking.

I removed distributor and coil to gain better access to the sensor for removal.

I've read that the brass elbow breaks easy. I'm using vice grips on the elbow to hold/support it while I try to remove the sensor.

I read a 1 1/16 wrench will fit it. It DOES not.

Any other recommendation without having to buy the sensor socket? Or any thoughts even if I do get the socket?

Attachment: oil_sensor.jpeg (240.67 KB) 11 View(s)




Joe

2005 Avalanche
1990 K1500 (snow plow truck)


 
someotherguy 
Senior Moderator
Posts: 29476
someotherguy
Loc: Texas
Reg: 08-01-03
07-21-21 10:13 AM - Post#2823626    
    In response to Joe_W

I've found the commonly-available socket for the sensor doesn't fit the original, but it does fit the replacement. Go figure. The original sensor was considerably larger.

I indeed ended up breaking the elbow and had to replace it... after using a square-style extractor set to pull the piece of elbow out of the block.

Wish I had better advice to offer than just "be really careful" - you're on the right path knowing that the elbow is super easy to break, and supporting it while attempting to remove the sensor. You could just try a large adjustable wrench to avoid buying tools that likely will not fit and end up with breakage regardless.

Richard

06 Silverado ISS / 06 Silverado SS / 06 300C SRT8


 
Joe_W 
Silver Supporting Member
Posts: 93
Joe_W
Loc: rural upstate westernNY
Reg: 11-14-20
07-21-21 10:34 AM - Post#2823629    
    In response to someotherguy

  • someotherguy Said:
I've found the commonly-available socket for the sensor doesn't fit the original, but it does fit the replacement. Go figure. The original sensor was considerably larger.

I indeed ended up breaking the elbow and had to replace it... after using a square-style extractor set to pull the piece of elbow out of the block.

Wish I had better advice to offer than just "be really careful" - you're on the right path knowing that the elbow is super easy to break, and supporting it while attempting to remove the sensor. You could just try a large adjustable wrench to avoid buying tools that likely will not fit and end up with breakage regardless.

Richard


I ended up buying the sensor socket tool and it worked very well. I was able to remove it without breaking the brass fitting. In fact the brass fitting busted loose in the block before the sensor did.
Anyway, got it all cleaned up and new sensor installed. Hopefully no more leaks.

Richard, it was your comments on other related posts that I had read that alerted me about how sensitive the fitting was to breakage and that I think really helped me avoid more problems. Thanks

Joe

2005 Avalanche
1990 K1500 (snow plow truck)


 
Joe_W 
Silver Supporting Member
Posts: 93
Joe_W
Loc: rural upstate westernNY
Reg: 11-14-20
07-21-21 11:51 AM - Post#2823635    
    In response to Joe_W

p.s.....I can NOT believe people have done this replacement with the distributor in place :crazy :

Joe

2005 Avalanche
1990 K1500 (snow plow truck)


 
someotherguy 
Senior Moderator
Posts: 29476
someotherguy
Loc: Texas
Reg: 08-01-03
07-21-21 12:06 PM - Post#2823638    
    In response to Joe_W

Awesome! Glad the socket worked for you. The one I found did not work for me! The plastic barrel on the original sensor was too large for the socket. It did help me install the replacement, though.

Brand/part # for the socket you used? I was going to dig through my box and post the one that didn't but found two and unsure at this point which one I tried back then.

Richard

06 Silverado ISS / 06 Silverado SS / 06 300C SRT8


 
454cid 
Valued Contributor
Posts: 3230

Age: 48
Loc: West Michigan
Reg: 02-18-12
07-21-21 02:29 PM - Post#2823645    
    In response to someotherguy

I just did this on my Vortec 454. I don't have the extra fitting, but the GM manual mentions is... the torque spec is lower for the fitting than for the sensor itself. I'm not sure if any of the Vortec trucks have the fitting or of it's just poor editing leaving in TBI era information.

I pulled my original sensor with an "OEM Tools" socket from Autozone. I did end up braking the plastic, but the socket fit over it fine. On my truck it's a job done entirely by feel... can't see anything at all.

The gauge works better now.... doesn't drift or get jumpy.

99 K3500 RCLB


 
Joe_W 
Silver Supporting Member
Posts: 93
Joe_W
Loc: rural upstate westernNY
Reg: 11-14-20
07-21-21 02:40 PM - Post#2823646    
    In response to someotherguy

  • someotherguy Said:
Awesome! Glad the socket worked for you. The one I found did not work for me! The plastic barrel on the original sensor was too large for the socket. It did help me install the replacement, though.

Brand/part # for the socket you used? I was going to dig through my box and post the one that didn't but found two and unsure at this point which one I tried back then.

Richard



OEMTOOLS #25254

Joe

2005 Avalanche
1990 K1500 (snow plow truck)


 
454cid 
Valued Contributor
Posts: 3230

Age: 48
Loc: West Michigan
Reg: 02-18-12
07-21-21 06:45 PM - Post#2823655    
    In response to Joe_W

  • Joe_W Said:


OEMTOOLS #25254



That looks like the same one I bought. I wish it would have been 3/8" drive and a bit lighter. I had multiple extensions, a drive adapter, and a u-joint involved doing my sensor.


99 K3500 RCLB


 
Joe_W 
Silver Supporting Member
Posts: 93
Joe_W
Loc: rural upstate westernNY
Reg: 11-14-20
07-22-21 04:37 AM - Post#2823670    
    In response to 454cid

  • 454cid Said:
  • Joe_W Said:


OEMTOOLS #25254



That looks like the same one I bought. I wish it would have been 3/8" drive and a bit lighter. I had multiple extensions, a drive adapter, and a u-joint involved doing my sensor.




I thought it was a little odd that it was a 1/2 drive, but didn't really matter. I removed distributor and coil giving me full exposure and room to work, and actually probably saving me time and frustration.

Joe

2005 Avalanche
1990 K1500 (snow plow truck)


 
someotherguy 
Senior Moderator
Posts: 29476
someotherguy
Loc: Texas
Reg: 08-01-03
07-22-21 01:24 PM - Post#2823701    
    In response to Joe_W

I dug into the toolbox and the sensor socket I've got is a glossy black un-named 3/8" drive "USA 1-1/16" with obvious sensor style flanges in the flats; I looked it up and it seems to be a Performance Tool brand piece part # W80590

While it *should* have worked on my 1992, it wouldn't fit over the plastic barrel of the original sensor. It is entirely possible the sensor was from a different application as the engine had already been swapped but from a similar vehicle. According to the mfgr (Wilmar) their page says: "Fits 1" and 1-1/16" size units on 1991 and newer GM 4 cyl. & 3.1 Liter V6 and 1987 and newer Chrysler." so it's possible the parts store I got it from just said "Oh yeah that fits GM" so I tried it.

Was your replacement sensor identical in appearance to the original, or did the original seem larger/longer?

Richard

06 Silverado ISS / 06 Silverado SS / 06 300C SRT8


 
Joe_W 
Silver Supporting Member
Posts: 93
Joe_W
Loc: rural upstate westernNY
Reg: 11-14-20
07-23-21 05:22 AM - Post#2823747    
    In response to someotherguy

Richard. The replaced sensor and new sensor appeared to be the same size and the specialty socket fit both nicely. My 1 1/6 wrench was too big to fit the nut part of the sensor and a 1" wrench was too small, meaning the specialty socket was indeed needed to fit the odd shape of the sensor.
Who knows if the replaced sensor was original.

On a different note, upon examination of the leaking sensor, the leak was not at the fitting, but was coming from inside the wire plug hole.

Joe

2005 Avalanche
1990 K1500 (snow plow truck)


 
Chevytech 
Subject Matter Expert - Senior Member
Posts: 3957
Chevytech
Loc: Twin Cities, Minnesota, U...
Reg: 04-25-04
07-23-21 08:31 AM - Post#2823759    
    In response to Joe_W

  • Joe_W Said:

On a different note, upon examination of the leaking sensor, the leak was not at the fitting, but was coming from inside the wire plug hole.


I have seen way to many Gm sensors leak out the terminals.

Coolant sensors are the ones I have seen this the most on, and it is hard to find a vehicle speed sensor at the U-Pull-It that does not leak.

The liquid can be forced up the wire all the way to the ECM causing failure.

For those of you that are wondering why you are not getting replies to your thread:

Did you give the model, year, engine, fuel system type, and transmission information?

If your vehicle has been altered from stock, let us know about that too.


 
Joe_W 
Silver Supporting Member
Posts: 93
Joe_W
Loc: rural upstate westernNY
Reg: 11-14-20
07-26-21 04:19 PM - Post#2823938    
    In response to Chevytech

Another interesting observation is that the PSI with the old leaking sensor was consistently around 30, but with the new one it's about 55. Any thoughts on this disparity?

Joe

2005 Avalanche
1990 K1500 (snow plow truck)


 
Chevytech 
Subject Matter Expert - Senior Member
Posts: 3957
Chevytech
Loc: Twin Cities, Minnesota, U...
Reg: 04-25-04
07-26-21 06:30 PM - Post#2823947    
    In response to Joe_W

  • Joe_W Said:
Another interesting observation is that the PSI with the old leaking sensor was consistently around 30, but with the new one it's about 55. Any thoughts on this disparity?


I have never cut one of these senders apart to see how they are constructed. Plenty of them fail.

For those of you that are wondering why you are not getting replies to your thread:

Did you give the model, year, engine, fuel system type, and transmission information?

If your vehicle has been altered from stock, let us know about that too.


 
sjohns4 
Poster
Posts: 80

Reg: 04-21-16
08-02-21 01:15 PM - Post#2824315    
    In response to Chevytech

When mine died in the ‘94 (RIP) I decided I wasn’t going through that again. A couple compression fittings and copper tubing and I relocated it to a home made firewall mount. Glad I did too. The first replacement was bad and showed really low oil pressure. Fortunately I had a tee and plug at the sensor connector so it was easy to connect a gauge.



 
udidwht 
Poster
Posts: 50

Reg: 08-08-17
08-08-21 06:25 PM - Post#2824757    
    In response to sjohns4

Using a line wrench will aid in removal without breaking the sensor.

1994 Fleetwood Southwind Storm 28ft
P-30 chassis 7.4L 454 TBI 58,306 miles and counting....as of 05/28/19
VIN# 1GBJP37N4R3314754


 
someotherguy 
Senior Moderator
Posts: 29476
someotherguy
Loc: Texas
Reg: 08-01-03
08-10-21 09:56 AM - Post#2824883    
    In response to udidwht

  • udidwht Said:
Using a line wrench will aid in removal without breaking the sensor.


The sensor isn't really the breakage concern - it's the brass 90° elbow the sensor is screwed into. I'm not sure how you could use a line wrench there but if you've got specifics it would be helpful to a lot of folks here.

The sensor itself takes a 1-1/16" sized sensor-type socket to remove; it's not a regular hex shape like a nut.

Richard

06 Silverado ISS / 06 Silverado SS / 06 300C SRT8


 
Icon Legend Permissions Topic Options
Report Post

Quote Post

Quick Reply

Print Topic

Email Topic

446 Views
FusionBB
FusionBB™ Version 2.1
©2003-2006 InteractivePHP, Inc.
Execution time: 0.076 seconds.   Total Queries: 17   Zlib Compression is on.
All times are (GMT -0800) Pacific. Current time is 05:30 AM
Top