Oil Press Sender R+R question

[TJ Moose]

So - given that I'm not planning on pulling the engine out, or the body off the frame anytime soon, what is the easiest way to change out the oil pressure sender. (Yes - I know - "First you grab your wrench.....")

From the top or underneath? Take off any other parts? Looking to make this as pain free (hmmm - pain free and 6.5 diesels - now THERE'S an oxymoron for ya) as possible.

We're talking a '95 'Burb 6.5 TD, 4WD, auto with a '99 vintage block in it. Thanks for any tips.

[john8662]

It's probably got all the 95 sensors and accessories mounted to the 99 block. So that means that the sender/switch is supposed to be located on the Drivers side rear of the engine.

To get access to this, you'll want to unbolt the fuel filter housing, this will allow you to get the bracket underneath the housing loose. You can either move the bracket with all the wiring slightly or unclip the connectors from the bracket. You should see the sender below. You will need the special oil pressure sender socket. Most auto parts stores carry it, it's kind of universal, well at least the one I bought is.

[damork]

I picked up a socket from Pep Boys and did mine from the top. Never removed the fuel filter but crawling over the top of the engine while doing was a real challenge.

Good time to incorporate a relay to handle the load so you don't have to continue replacing the sender. I found the wire in the harness feeding power to the lift pump then spliced into it so it would trigger a Bosch relay (like used for off road lights) to power the lift pump instead. Real simple upgrade.

[tom.mcinerney]

Yes the OPS is rear of driver's head , mounted to a 90-degree brass fitting , so it lies near horizontal , pointing toward the fuel conditioner.

I can send photos, but even without head it's scarcely visible , and best located by following harness.

If you install a relay, get the more expensive Bosch type featuring a built-in diode to 'clamp reverse emf' [prevent the coil's electric characteristics damaging the transistor drive in the LP].

John Kennedy has recently brought to market a solid state solution which preserves the OPS and LP.

[TJ Moose]

Yeah - I had just installed a Heath balance flow setup to the back coolant ports on top of the block in the back, so I know all about the fun to be had stretching to the back of the engine. And I should have done the OPS while I was at it - but ran out of time before I had to get the 'Burb back on the road, and wasn't having much luck locating the dang thing. I think my LP is still being driven properly, but the OPS has definitely seen better days - indicated (I assume)by a spiking/jumping pressure gauge on occasion, and other indications of a sender going south. I understand the deal with driving the LP via solenoid rather than OPS, and will see what JK has. Thanks for the tips. I always appreciate the experiences of those who have gone before......
Oh - one more question. I assume in order to do this just once, I'd do well to use a pipe thread sealer on the threads of the OPS?

[mhagie]

Check out my pics where I relocated OPS to firewall,mine is the mech inj but the principal is the same.
I have factory OPS a mech oilpressure gauge line and a press switch for my aux elec fuel pump all on a fuel block from Summit.
Merle

[tom.mcinerney]

A dab of sealant won't hurt. But i think it's diecast light metal into brass , tapered pipe threads, so it shouldn't really need it. The sealer will cover any debris in threads...

[landrea]

The voice of experience speaking here,the new sender from GM comes with teflon sealer already on the threads.Next time one of mine goes bad I'm going to relocate it to the valley on top like the late model trucks (like my 2000)and add the relay on the firewall.I'm told the valley mounting is more accurate.

[N9Phil]

I use a 3/8 in extension that is about 2 ft. long. Once I put the put the socket on the ops, I can stand on the drivers side of the engine and remove the ops. Of course you still have to lean across the engine to connect the socket and the wires but I still can do the job without to much pain and in about 10 minutes.

N9Phil