Oil pressure indication problem

Oil Pressure light will not go out

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Buddhahoodvatoloco
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Re: Oil pressure indication problem

#31

Post by Buddhahoodvatoloco » Mon Aug 12, 2019 1:10 pm

Tis munchas palabras,
ENEMY, more like a avocation..
old man emu wrote:
Mon Aug 12, 2019 6:50 am
“If you know the enemy and know yourself, you need not fear the result of a hundred battles.
If you know yourself but not the enemy, for every victory gained you will also suffer a defeat.
If you know neither the enemy nor yourself, you will succumb in every battle.”

Wise words to a maintainer of these bikes.



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Re: Oil pressure indication problem

#32

Post by kitabel » Mon Aug 12, 2019 1:40 pm

Sun Tzu said some foolish things.

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Re: Oil pressure indication problem

#33

Post by Andygears » Mon Aug 12, 2019 10:38 pm

Buddhahoodvatoloco wrote:
Mon Aug 12, 2019 12:18 am
Now that is turning it into Rocket Science, good job.
Andygears

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Re: Oil pressure indication problem

#34

Post by old man emu » Wed Aug 14, 2019 12:01 pm

PROBLEM SOLVED

It's always the smallest thing that stops these bikes, and I think I found the smallest of the small.

After running all the tests that I have described, I was thinking of cleaning the oil off the old sensor and giving it a polish. As I was handling it, I noticed what I thought was a very small black spot of crud on it. I tried to wipe it away, but on closer inspection I discovered that it was a hole, obviously put there by the manufacturer, and it was clogged with crud.
vent.png
I realised that the hole was a vent to release the air above the diaphragm when the oil pressure below it moved the diaphragm. Moving the diaphragm breaks the connection between the switch points so the warning light goes out. If the vent is clogged, then the pressure above the diaphragm increases and makes it impossible for the oil pressure to move the diaphragm, so the switch points stay closed.

Using a fine piece of wire, I cleared the crud; refitted the sensor and started the engine. The light went out straight away and remained out until I stopped the engine.

So now we all know how the oil pressure sensor works and what can cause it to send an erroneous message to us.
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Re: Oil pressure indication problem

#35

Post by Buddhahoodvatoloco » Wed Aug 14, 2019 10:27 pm

Rocket science, the best lesson learned, is the one your realized you learned. dam good job matey. :lol: :D :)
old man emu wrote:
Wed Aug 14, 2019 12:01 pm
PROBLEM SOLVED

It's always the smallest thing that stops these bikes, and I think I found the smallest of the small.

After running all the tests that I have described, I was thinking of cleaning the oil off the old sensor and giving it a polish. As I was handling it, I noticed what I thought was a very small black spot of crud on it. I tried to wipe it away, but on closer inspection I discovered that it was a hole, obviously put there by the manufacturer, and it was clogged with crud.

vent.png

I realised that the hole was a vent to release the air above the diaphragm when the oil pressure below it moved the diaphragm. Moving the diaphragm breaks the connection between the switch points so the warning light goes out. If the vent is clogged, then the pressure above the diaphragm increases and makes it impossible for the oil pressure to move the diaphragm, so the switch points stay closed.

Using a fine piece of wire, I cleared the crud; refitted the sensor and started the engine. The light went out straight away and remained out until I stopped the engine.

So now we all know how the oil pressure sensor works and what can cause it to send an erroneous message to us.

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Re: Oil pressure indication problem

#36

Post by old man emu » Wed Aug 14, 2019 10:45 pm

Please! You are embarrassing me!

One has to learn to trust those wizards at H-D back in the day who made a simple and easily maintained machine. However, I may have over-thought this problem.

I'm going to keep saying that it was the blocked vent hole that caused the problem, but I thought of another reason.

Because one of the check valve balls was not in place, and the bike was sitting unused for some months, the oil drained from the tank into the crankcase. I drained that oil out and refilled the oil tank, and fitted new steel check valve balls Because the check valves had been fixed, no oil drained into the engine.

When I first started the engine, all the oil galleries were empty, so the first thing the pump had to do was to fill them so that there was oil in the system to resist the flow of oil from the pump which creates the pressure to operate the sensor. When I was first starting the bike, it was only running for about 30 seconds before I stopped it. So the warning light kept coming on. After several starts the oil galleries must have filled, so when I started the bike there was oil in them to resist the flow from the pump and so the pressure built up and the light went out.

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Re: Oil pressure indication problem

#37

Post by liberator » Thu Aug 15, 2019 1:33 pm

Whatever..problem solved, that's what counts!
Contrast on tour achievement!

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Re: Oil pressure indication problem

#38

Post by liberator » Thu Aug 15, 2019 9:09 pm

My freekin' phone likes fiddling with my words.

It should have read; congrats on your achievement!

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Re: Oil pressure indication problem

#39

Post by old man emu » Thu Aug 15, 2019 11:25 pm

liberator wrote:
Thu Aug 15, 2019 9:09 pm
My freekin' phone likes fiddling with my words.It should have read; congrats on your achievement!
That's alright. I'm fluent in Auto-correct.

However, I failed to follow my dear mother's warning - Don't p!ss before your water comes. The problem hasn't gone away. Now the light will go out for a short time, then come back on and won't go out. I've replaced the wire in the section that could be heat affected. Next time I get a chance to work on the bike, I'll have a look at the wiring around the instrument panel.

Is it safe to blow pressurised air (about 30 psi) into the hole where the sensor is fitted and blow the oil galleries clear?

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Re: Oil pressure indication problem

#40

Post by liberator » Fri Aug 16, 2019 4:23 pm

Why shouldn't it not be?
All you do is blow oil out..

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Re: Oil pressure indication problem

#41

Post by PanPal » Fri Aug 16, 2019 4:28 pm

Since you played with your balls and springs, It sounds more likely to be a oil flow issue rather than a electrical issue. Proceed with caution!

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Re: Oil pressure indication problem

#42

Post by old man emu » Fri Aug 16, 2019 10:43 pm

liberator wrote:
Fri Aug 16, 2019 4:23 pm
Why shouldn't it not be? All you do is blow oil out..

Thanks. I needed to be assured that I wasn't going to wreck anything.

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Re: Oil pressure indication problem

#43

Post by old man emu » Sun Aug 25, 2019 3:02 am

August 25 - The saga continues.

I attacked two possible causes for the oil warning light not going out:
  • 1. There was a short in the wire from the instrument panel to the pressure switch
    2. There was something clogging the oil galleries.
I examined a length of the wire from under the seat to the switch. The wire was heat affected, but there was no sign of a break in the insulation which would result in a short circuit, causing the light to stay on. I replaced that length of wire and started the motor. Not fixed.

Then I checked the setting of the pressure regulating valve to make sure that the top of the adjusting screw was 3/8" below the top of the pump body.

Next I introduced pressurized air into the engine via the pressure switch hole. I first set the pressure at about 4 psi and blew that air in for a few moments. The I set the pressure at 30 psi and blew air into the engine until I could hear the air bubbling through the oil in the tank. Replaced the switch and started the engine. Light out!

I can't explain why blowing air through the galleries would affect the operation of the pressure switch, which is located before the oil gets into the engine. However, if the problem is fixed, I can get my annual roadworthiness inspection on Monday, pay the registration fee, and start riding.

Thanks for following my trail through the wilderness.

OME

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Re: Oil pressure indication problem

#44

Post by ozwick86 » Sun Aug 25, 2019 5:45 am

You would think that 4 psi would produce bubbling at the oil tank? When you increased the pressure to 30 psi, maybe you dislodged some crap allowing the air to flow?

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Re: Oil pressure indication problem

#45

Post by Andygears » Sun Aug 25, 2019 1:03 pm

Great! If you got the problem fixed, really I’m glad for you!

However, a few pages ago I suspected the spring was incorrect and asked for measurements and a picture. Think if the spring is the wrong diameter and binding in the bore, and also has too much tension. Then, enough pressure would unseat the ball, but would allow “wet sumping” until the ball seated again from vibration or complete loss of pressure after the bike sat awhile. When a solution shows up with lingering questions WHY? Conjecture is warranted.

Really I’m glad if you got it fixed, I hope it is.

Andygears

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