No Oil Pressure after oil change (MF135)

[lkell93]

I've owned this 1970 MF135 (Perkins gas) for about a year. I got around to changing the engine oil and filter yesterday, and when I attempted to start today, I noticed the oil pressure gauge didn't move at all, so I shut off the machine.

I know the gauge had worked only a few weeks ago when I looked last.

I removed the new oil filter and put the old one back on to test, still no reading on the gauge.

I just now drained the clean oil out of the machine and am trying to figure out what to do next.

Any suggestions?

 

[Jim.ME]

I would start by trying a different gauge or checking the gauge on a known good pressure source.

 

[lkell93]

I would start by trying a different gauge or checking the gauge on a known good pressure source.

I've ordered an oil pressure gauge and it'll get here tomorrow.

I assume I can just check the pressure by pulling the coil wire and cranking the engine over? Or do I need to start the engine for a few seconds?

I did use a bit of PTFE tape (2 wraps), on the drain plug, as it had some on it when I'd originally removed it (drain plug appears to have been welded/retapped at some point, and it has a slow drip, which was apparently the reason for the tape).

 

[Jim.ME]

I've ordered an oil pressure gauge and it'll get here tomorrow.

I assume I can just check the pressure by pulling the coil wire and cranking the engine over? Or do I need to start the engine for a few seconds?

I did use a bit of PTFE tape (2 wraps), on the drain plug, as it had some on it when I'd originally removed it (drain plug appears to have been welded/retapped at some point, and it has a slow drip, which was apparently the reason for the tape).

You may see some pressure by cranking or you might need to start it for a few seconds, I don't know how fast it came up before and if it ever showed on the gauge while cranking.

 

[used red MN]

I've ordered an oil pressure gauge and it'll get here tomorrow.

I assume I can just check the pressure by pulling the coil wire and cranking the engine over? Or do I need to start the engine for a few seconds?

I did use a bit of PTFE tape (2 wraps), on the drain plug, as it had some on it when I'd originally removed it (drain plug appears to have been welded/retapped at some point, and it has a slow drip, which was apparently the reason for the tape).

If not obvious you’ll have to put the oil back in the engine. I would run it 15 seconds, shut it off. If it doesn’t show oil pressure in that bit of time you will have to investigate the cause.

 

[lkell93]

If not obvious you’ll have to put the oil back in the engine. I would run it 15 seconds, shut it off. If it doesn’t show oil pressure in that bit of time you will have to investigate the cause.

Thanks...I just undid the steel tube fitting that goes from the block to the pressure gauge and cranked the engine, a very strong spurt of oil came shooting out...so I'm hopeful this is just a case of a bad gauge.

This engine only has about 300 hours on it since it was rebuilt, so I think I'm going to probably play it safe and get the oil pressure gauge on it tomorrow just to make sure before I run the engine.

It seems strange that the gauge would malfunction around the time of my first oil change, but then again they appear to be cheap aftermarket Chinese gauges, so who knows.

Also, I guess I'd never really paid that close of attention to the oil pressure gauge at startup, maybe it always took a while to build up pressure, but it seems odd that the gauge needle wouldn't as much as flutter, especially now that I've confirmed there is some pressure on that line.

 

[used red MN]

Thanks...I just undid the steel tube fitting that goes from the block to the pressure gauge and cranked the engine, a very strong spurt of oil came shooting out...so I'm hopeful this is just a case of a bad gauge.

This engine only has about 300 hours on it since it was rebuilt, so I think I'm going to probably play it safe and get the oil pressure gauge on it tomorrow just to make sure before I run the engine.

It seems strange that the gauge would malfunction around the time of my first oil change, but then again they appear to be cheap aftermarket Chinese gauges, so who knows.

Also, I guess I'd never really paid that close of attention to the oil pressure gauge at startup, maybe it always took a while to build up pressure, but it seems odd that the gauge needle wouldn't as much as flutter, especially now that I've confirmed there is some pressure on that line.

I’ll go with the likely bet on a bad gauge.

 

[Jim.ME]

Thanks...I just undid the steel tube fitting that goes from the block to the pressure gauge and cranked the engine, a very strong spurt of oil came shooting out...so I'm hopeful this is just a case of a bad gauge.

This engine only has about 300 hours on it since it was rebuilt, so I think I'm going to probably play it safe and get the oil pressure gauge on it tomorrow just to make sure before I run the engine.

It seems strange that the gauge would malfunction around the time of my first oil change, but then again they appear to be cheap aftermarket Chinese gauges, so who knows.

Also, I guess I'd never really paid that close of attention to the oil pressure gauge at startup, maybe it always took a while to build up pressure, but it seems odd that the gauge needle wouldn't as much as flutter, especially now that I've confirmed there is some pressure on that line.

It is not uncommon for it to take a few seconds of run time to fill a filter after an oil change, then pressure the line to the gauge to get a reading.

 

[504]

You now know why I prefill my oil filters when I change oil

 

[lkell93]

You now know why I prefill my oil filters when I change oil

Yep, I've not done that with any of my vehicles in the past, but given the taller filter on this, I probably should have here...

Odd thing is that even after I put the old filter (full of oil) back on, the gauge doesn't move (but as mentioned above, I do seem to get strong pressure out of the gauge fitting in the block.

I'll feel much better after I hook up a different gauge to the port tomorrow and know for certain. There's something very unsettling about running the machine and seeing the oil pressure gauge bottomed out.

 

[Frankmn]

Thanks...I just undid the steel tube fitting that goes from the block to the pressure gauge and cranked the engine, a very strong spurt of oil came shooting out...so I'm hopeful this is just a case of a bad gauge.

This engine only has about 300 hours on it since it was rebuilt, so I think I'm going to probably play it safe and get the oil pressure gauge on it tomorrow just to make sure before I run the engine.

It seems strange that the gauge would malfunction around the time of my first oil change, but then again they appear to be cheap aftermarket Chinese gauges, so who knows.

Also, I guess I'd never really paid that close of attention to the oil pressure gauge at startup, maybe it always took a while to build up pressure, but it seems odd that the gauge needle wouldn't as much as flutter, especially now that I've confirmed there is some pressure on that line.

Are you saying you ran a rebuilt motor 300 hours before changing the break in oil?
Just curious as i just got my perkins gas rebuild finished up and I was thinking about changing the oil at 10 hours.
Is that carried away or what do you guys recommend?

 

[lkell93]

Are you saying you ran a rebuilt motor 300 hours before changing the break in oil?
Just curious as i just got my perkins gas rebuild finished up and I was thinking about changing the oil at 10 hours.
Is that carried away or what do you guys recommend?

No, just was saying this engine was rebuilt not that long ago and I didn't want to risk damaging it.

 

[lkell93]

Before I go and booger this fitting up trying to remove it from the block, and suggestions on how to get it off? There are no flat edges for a wrench to get a hold on it.

I put the closest fitting wrench on it I could find, and it won't budge.

 

[used red MN]

Yep, I've not done that with any of my vehicles in the past, but given the taller filter on this, I probably should have here...

Odd thing is that even after I put the old filter (full of oil) back on, the gauge doesn't move (but as mentioned above, I do seem to get strong pressure out of the gauge fitting in the block.

I'll feel much better after I hook up a different gauge to the port tomorrow and know for certain. There's something very unsettling about running the machine and seeing the oil pressure gauge bottomed out.

Put the proper sized box end wrench over the line nut slide it back over the tubing, screw the line nut down snug. Place the box end on the line nut to where you can add leverage to loosen the fitting. Using both wrenches turn the fitting just enough to pop it loose from its “set” in the threads. After it is broke loose remove as normal. An adjustable wrench “Crescent” may be the best tool for this job. You may also find a metric wrench size that fits better.
Edit: Oops, put it under the wrong reply.

 

[Jim.ME]

A Weatherhead socket was likely used.

One possibility, you may be able to get it by putting a tight-fitting open-end wrench jaws straight down (as a socket extension would go on a socket) on the fitting and using an adjustable to turn the handle of the open-end wrench.

Weatherhead sockets

 

[lkell93]

Thank you both for the recommendations. I noticed there was an adapter on the dash gauge end, so I removed the gauge and threaded the adaptor on the threaded elbow I was trying to remove in the previous picture.

I'm quite relieved, as you'll see in the attached image, I do have pressure (cranked it over about 10 seconds).

 

[lkell93]

Now, I plan to order a Bosch pressure gauge to replace the Chinese one that came on the tractor. I see no blockage in the old gauge, nor is there a blockage in the steel flared line that runs to the gauge. Apparently it just so happened that the gauge gave up right around the time I did the first oil change.

Now, one final question for you all. After the most recent oil draining yesterday (since been refilled), I put the drain plug back in without tape (my first though when I saw there was no pressure was that tape had somehow blocked off the oil pickup). It has a pretty consistent, slow drip.

So...is it worth a risk to wrap the plug once or twice with tape, or just leave it without and let it drip?

 

[Jim.ME]

Now, I plan to order a Bosch pressure gauge to replace the Chinese one that came on the tractor. I see no blockage in the old gauge, nor is there a blockage in the steel flared line that runs to the gauge. Apparently it just so happened that the gauge gave up right around the time I did the first oil change.

Now, one final question for you all. After the most recent oil draining yesterday (since been refilled), I put the drain plug back in without tape (my first though when I saw there was no pressure was that tape had somehow blocked off the oil pickup). It has a pretty consistent, slow drip.

So...is it worth a risk to wrap the plug once or twice with tape, or just leave it without and let it drip?

The drain plug is supposed to have a sealing washer on it. You haven't mentioned a washer, is it there? They are usually copper or aluminum.

Be sure you get an oil pressure gauge with the same port on the back as what you have.

 

[lkell93]

The drain plug is supposed to have a sealing washer on it. You haven't mentioned a washer, is it there? They are usually copper or aluminum.

Be sure you get an oil pressure gauge with the same port on the back as what you have.

At some point in the tractor's life, someone must have really stripped out the factory drain hole, as there is a threaded bung that's been welded onto the pan and the drain plug is just a steel pipe plug that threads into it. There unfortunately wouldn't be a way to get a crush washer on it, as it is.

 

[Jim.ME]

At some point in the tractor's life, someone must have really stripped out the factory drain hole, as there is a threaded bung that's been welded onto the pan and the drain plug is just a steel pipe plug that threads into it. There unfortunately wouldn't be a way to get a crush washer on it, as it is.

You might try using a Teflon based paste, rather than tape. A brass plug might work better as well, it will be softer and conform to the threads better