Oil Light on

[winston1]

Interesting. Sure sounds like your sending unit is to come on at 4.35psi. I checked the 276 repair manual and it too states 14.2psi for oil light to come on. Hoyes also shows same sending unit for it. Puzzling to me. :confused3:

 

[flyerdan]

It sounds like a low pressure switch that opens at 4.35 psi. You can test it with a DMM or test light circuit and poke the flat end of a drill bit up there and see if it trips, pressing it down on a postage scale would give the rating when (if) it does. If it has failed, chances are high that the rubber diaphragm has a hole or tear, letting the pressure equalize on both sides of the spring.

 

[Neat 1500]

Interesting. Sure sounds like your sending unit is to come on at 4.35psi. I checked the 276 repair manual and it too states 14.2psi for oil light to come on. Hoyes also shows same sending unit for it. Puzzling to me. :confused3:

I think that's a typo. I'd imagine it would be 4.2 PSI. 14.2 is way too high. With thin oil in it on a hot day your oil light would be on at idle.

 

[winston1]

I think that's a typo. I'd imagine it would be 4.2 PSI. 14.2 is way too high. With thin oil in it on a hot day your oil light would be on at idle.

Your probably right but is seems even stranger there would be a typo in two different manuals. Anyone out there have a repair manual for a 1700/2000 that would want to look in their manual. Information is under "Electrical operation and tests" section, then specifications in both 220/226 and 276 manuals.

Forgot I had a 135/155 manual. It states the sender is actuated at 2.84psi so no doubt Neat, you are likely correct.

Looked into a Yanmar TNE series repair manual and their sensors are to come on at 5.689 to 8.534 psi. More confirmation Neat is correct.

 

[Neat 1500]

Your probably right but is seems even stranger there would be a typo in two different manuals. Anyone out there have a repair manual for a 1700/2000 that would want to look in their manual. Information is under "Electrical operation and tests" section, then specifications in both 220/226 and 276 manuals.

Forgot I had a 135/155 manual. It states the sender is actuated at 2.84psi so no doubt Neat, you are likely correct.

Looked into a Yanmar TNE series repair manual and their sensors are to come on at 5.689 to 8.534 psi. More confirmation Neat is correct.

The 135/155 had oil pressure problems from new so an even lower trigger point would be right for it too!

 

[California]

Your probably right but is seems even stranger there would be a typo in two different manuals. Anyone out there have a repair manual for a 1700/2000 that would want to look in their manual. Information is under "Electrical operation and tests" section

YM240 Service Manual page 62: Oil pressure switch - Activating pressure 14.22 psi (1kg/cm2).

And I googled the psi/metric conversion. The psi stated is the correct conversion of 1kg/cm2.

This still sounds high to me. However ...

The I&T shop manual discussion of oil pumps shows similar the posts above - lower minimum pressure for the little YM135 etc with the oil pump at the rear of the camshaft, then this higher minimum for the larger models with oil pump at the front.

 

[clemsonfor]

I looked in my yanmar ym240 service manual and mine obviously is identical to California. Page 62 the spec is 14.22 psi the metric equivalent is 1kg/cm^2 so it's not a mixed up units thing as they don't even corrolate?

 

[shovelrider]

so, is the one i have correct? In all opinion. Jim

 

[Neat 1500]

I also looked up 70s Datsun OP switch and it says 6 PSI + or - 3 PSI! Bit of variation in them.....

 

[California]

I also looked up 70s Datsun OP switch and it says 6 PSI + or - 3 PSI! Bit of variation in them.....

Hmmm. looks like that generic switch is suitable only for the smaller (rear oil pump) YM135 etc.

 

[flyerdan]

One thing to watch out for when shopping for replacement senders is threads. Datsun (and Nissan) uses BSP threads on their sender units, a holdover from colonialism. It looks similar to 1/8" NPT, but there are a lot of posts on the Datsun forums about the bad things that can happen when it's overlooked. It's not inconceivable that Japanese manufactured tractors might share the same trait, especially if the manufacturing facility has been around since the 50's-60's.

 

[California]

I wouldn't try threading NPT iron threads into a Yanmar block. But I experimented with several brass NPT fittings I had in the barn, I think they are old gas lighting plumbing and certainly not BSP or metric. Some were too large diameter at the first thread to start threading, others threaded in a few turns by hand and then I wrench-tightened them. None came out distorted after this experiment. And the block wasn't hurt by this - the Japanese (BSP) sender I ultimately installed threaded in easily and sealed as it was intended to do.

Are those Datsun-forum owners talking about threading iron NPT into an aluminum front cover or something? I can see how that could strip threads.

Looks like Hoye sells the same sender for little (YM 1100) and larger (YM2000) models. They also offer an adapter to put NPT gauges etc into 'Yanmar' threads.

 

[flyerdan]

Here's a thread on the differences between BSP and NPT. I think the major problems in the Ratsun community is threading in a junkyard GM sender until it breaks off, and the problems getting it out, especially with hammer mechanics who aren't as skilled with some of the finesse required for such situations.

 

[shovelrider]

changed oil(sae-30w for diesel), replaced filter(wix-51334, and put ImportedParts #18-1568(O'reillys) oil sending unit in. No problems w/the oil sending unit thread wise. Light is off and runs like it should, will add 'T' and gauge w/copper tubing ltr. this week. Thanks to all for info. Jim

 

[clemsonfor]

Only difference is I would of used 15w40. Diesel oil. So it would flow better cold. And be a tad Thocker here when its 98F here and I am bushhogging