3B Fuel pump leaking ?

[NielsC]

Hi all,

I've got a 3B engine lying that has to be fit into my BJ40.
I've noticed that the little tube on the side of the fuel pump is leaking oil. Is this supposed to or what is the tube's purpose? A fair amount of oil already came out of it.

It's the red circled tube.

 

[lostmarbles]

My BJ40 has a plug there instead of a hose. And it is there to drain engine-oil that gets past the seals into the space just forward of the governor-diaphragm.

I remove my plug and drain the oil every couple of years and each time I usually get a small dribble coming out.

Engine oil is not good for the life of the leather diaphragm - so that's why it is important to prevent too much of it collecting in there..



PS. I've seen a few others with hoses like you have

 

[handcannon]

Tom, and any others that know the answer to my question. I need to be educated about the diaphragm in the IP on the B series motors.

I have a 1982 Nissan SD-22 diesel motor that has a very similar diaphragm system to the B series motor, and here is a very simplified description of how I understand how it operates. The diaphragm is hooked to the rack, There is a vacuum hose between the venturi (throttle valve area) and one side of the diaphragm, and another hose (non-vacuum) that goes from just before the venturi to the opposite side of the diaphragm. The throttle peddle (foot peddle) controls the throttle valve, which in turn controls the amount of vacuum that operates the diaphragm/rack.

My question centers around the statement that Tom made about occasionally draining engine oil that slowly collects in the diaphragm area as the engine oil is detrimental to the health of the leather diaphragm. If engine oil is detrimental to the life of the leather, is there an oil that doesn't harm the leather?

I remember reading somewhere that in the B series IP neatsfoot oil is used to lubricate the diaphragm, and keep it soft and supple. However, in the diaphragm for the SD-22 neatsfoot oil is not recommended as it will gum up over time and make the leather diaphragm stiff and unable to properly react to the vacuum from the venturi. I have seen pictures of the gum/goo from neatsfoot oil left on the leather diaphragm in the SD-22. Maybe the leather used in the two different diaphragms is treated/cured in a different way, and allowing neatsfoot oil to be used in the B series diaphragm.

Anyway, I'm very curious, and want to learn all about this oil situation, and how it may affect the oil I need to use on my SD-22 diaphragm.

Don

 

[NielsC]

My BJ40 has a plug there instead of a hose. And it is there to drain engine-oil that gets past the seals into the space just forward of the governor-diaphragm.

I remove my plug and drain the oil every couple of years and each time I usually get a small dribble coming out.
View attachment 1214875


Engine oil is not good for the life of the leather diaphragm - so that's why it is important to prevent too much of it collecting in there..



PS. I've seen a few others with hoses like you have

Hi thanks for reply.
I understand what you are saying, but my engine is on a stand , and out the car. I just bought the engine to replace my B engine. It hasn't run for a year and i think and there really came a fair amount of oil out of it. Could it be that some seals inside the pump are leaking badly if alot of oil came out mine?
Regards

 

[lostmarbles]

Hi thanks for reply.
I understand what you are saying, but my engine is on a stand , and out the car. I just bought the engine to replace my B engine. It hasn't run for a year and i think and there really came a fair amount of oil out of it. Could it be that some seals inside the pump are leaking badly if alot of oil came out mine?
Regards

Our inlne pumps regularly last 600,000kms and more without ever needing anything other than diaphragm changes (and the diaphragm maintenance work of oil-draining and adding drips of Neatsfoot oil) so I very much doubt anything is wrong.

Furthermore, oil can't enter that chamber without oil pressure because your IP is above the level of oil in your engine's sump and relies on the engine's oil pump for lubrication. So I believe whatever oil has dribbled out must have got in there a long time ago and the reason it has dribbled out now I think is probably

• the engine has been tilted at a different angle, or
• a slight blockage in the hose has cleared, or
• something else like that.

PS. On engines made prior to Sept 1977 the IP had it's own oil (separate from the engine's oil) with it's own oil level dipstick. But even with these early engine's I don't think the oil could travel into that chamber without the engine running.

 

[lostmarbles]

Tom, and any others that know the answer to my question. I need to be educated about the diaphragm in the IP on the B series motors.

I have a 1982 Nissan SD-22 diesel motor that has a very similar diaphragm system to the B series motor, and here is a very simplified description of how I understand how it operates. The diaphragm is hooked to the rack, There is a vacuum hose between the venturi (throttle valve area) and one side of the diaphragm, and another hose (non-vacuum) that goes from just before the venturi to the opposite side of the diaphragm. The throttle peddle (foot peddle) controls the throttle valve, which in turn controls the amount of vacuum that operates the diaphragm/rack.

My question centers around the statement that Tom made about occasionally draining engine oil that slowly collects in the diaphragm area as the engine oil is detrimental to the health of the leather diaphragm. If engine oil is detrimental to the life of the leather, is there an oil that doesn't harm the leather?

I remember reading somewhere that in the B series IP neatsfoot oil is used to lubricate the diaphragm, and keep it soft and supple. However, in the diaphragm for the SD-22 neatsfoot oil is not recommended as it will gum up over time and make the leather diaphragm stiff and unable to properly react to the vacuum from the venturi. I have seen pictures of the gum/goo from neatsfoot oil left on the leather diaphragm in the SD-22. Maybe the leather used in the two different diaphragms is treated/cured in a different way, and allowing neatsfoot oil to be used in the B series diaphragm.

Anyway, I'm very curious, and want to learn all about this oil situation, and how it may affect the oil I need to use on my SD-22 diaphragm.

Don

Hi Don... A perfect description!

As for gumming up, I think that's only possible is someone is overzealous with the application of the Neatsfoot oil. It is only supposed to be a couple of drops every couple of years (or every second oil change or similar).

It is true that if you were to poor a little pool of the stuff it would soon dry out to a glue-like gum. But I've changed my leather diaphragm more than once and the old one has always come out nice and supple/pliable.

This is one of my old ones inside this plastic bag:

 

[handcannon]

Thanks for the reply Tom. What you said about the neatsfoot oil does help with my concerns. The SD-22 is almost an orphan here in the states, and my concern is for doing everything I can to support the longevity of the motor. I did find a spare diaphragm to have on hand, just in case.

In the same web site thread another person chimed in saying he had successfully used vacuum pump oil instead of neatsfoot oil. This vacuum pump oil was described, if I remember correctly, as a very light oil like a hydraulic oil. I'll have to look that thread up again and re-read it so I can get a better idea stuck in my head of what that oil actually was.

By the way, the SD-22 has an IP control system similar to the EDIC system. I never got all the electrical control system with the motor for the "EDIC" (Nissan has a different name for it), but I have made a hand control switch for it that seems to work part of the time. The electric "EDIC" motor doesn't always want to stop correctly at the three different locations, just like 12 volt is too high a voltage and is causing the "EDIC" motor to overrun the stop positions.

Don

 

[lostmarbles]

I used to know a bit about vacuum pump oil because my trade background is "refrigeration and air conditioning" and we used to pull high-vacuums on systems quite regularly prior to charging them with refrigerant for the first time. (Sometimes the specifications called for such low pressures that it involved multiple dry-nitrogen purges and running the high vacuum pumps for many days on end.)

But alas I've forgotten almost everything about it now Don

I remember it's sold in sealed containers to keep the air (and it's moisture content) out. And as well as it's ability to lubricate bearings and seals it obviously must not contain any component fluid that "vaporises" under the high vacuum. But as far being compatible with leather .... I have no memory of anything there...



PS. I remember also that we had to change the vacuum pump oil regularly too (and that inability to pull a decent vacuum could often be attributed to moisture-contaminated oil) and that the pump was always left sealed from the air when not in use.

 

[handcannon]

I feel a need to make a correction to my previous post. I took a bit of time to re-locate the forum/thread that referred to neatsfoot oil for lubricating the diaphragm. My memory was faulty (not a new phenomenon) when I stated I had seen a picture of a diaphragm all gummed up from neatsfoot oil. Instead of neatsfoot oil, the oil used was cod liver oil. The website is
NissanDiesel forums • View topic - * Pneumatic Governor Diaphragm *
and the information can be found in posts #1-4 and 11-12 on the first page, and posts 35-39 on the third page.

Apparently the neatsfoot oil worked OK, with some stiffening of the new leather diaphragm, which may be due to residue left over from the cod liver oil. The vacuum pump oil seems to have successfully worked for at least four years, and someone used powersteering oil/hydraulic fluid for at least six years.

So, maybe something besides neatsfoot oil can work.

Don

 

[lostmarbles]

I feel a need to make a correction to my previous post. I took a bit of time to re-locate the forum/thread that referred to neatsfoot oil for lubricating the diaphragm. My memory was faulty (not a new phenomenon) when I stated I had seen a picture of a diaphragm all gummed up from neatsfoot oil. Instead of neatsfoot oil, the oil used was cod liver oil. The website is
NissanDiesel forums • View topic - * Pneumatic Governor Diaphragm *
and the information can be found in posts #1-4 and 11-12 on the first page, and posts 35-39 on the third page.

Apparently the neatsfoot oil worked OK, with some stiffening of the new leather diaphragm, which may be due to residue left over from the cod liver oil. The vacuum pump oil seems to have successfully worked for at least four years, and someone used powersteering oil/hydraulic fluid for at least six years.

So, maybe something besides neatsfoot oil can work.

Don

LOL. I think it's likely that your memory isn't the only one at fault here Don. I'd love to see the Nissan FSM Supplement that Philip (in that link) says specifies Cod Liver Oil.

Both oils saw widespread use in days gone by but enjoy little use today and because they're both in this same category I think it would be easy to confuse them.

Errr. But maybe I should see if I can find that mystery "Nissan FSM suppliment" before posting this ...

Soo.....

After downloading the Nissan SD-series FSM .... voila:

We've tracked where this misinformation has come from and it is certainly a Nissan official publication:

I think this technical writer (working for Nissan or contracted by Nissan) has made a stuff-up and has a lot to answer for.



PS. For many years I was employed (by the NZ Technical Correspondence Institute) as a technical writer so I can assure you that such people do indeed make mistakes.

Edit: Perhaps that's not the only mistake in the above image...

Notice how it says drain fuel from the chamber there on the left! Shouldn't that be "oil". (I think I'd be quite worried if I found fuel in there!)

 

[handcannon]

I find that very interesting Tom. Thank you for posting that.

Don

 

[lostmarbles]

Hi again Don

I was thinking about this subject and figured I should really research it more thoroughly..

I've found that people who work with leather (making holsters, saddles or whatever) do use products like Cod Liver Oil and even "Extra Virgin Olive Oil" as well as Neatsfoot Oil on their leather, and they debate things like

• whether Neatsfoot attacks stitching (on the basis that it is slightly acidic)
• which oil darkens the leather the least
• which oil attracts rodents
• which oil soaks in fastest
• which oil has the best/least odour
• which oil soaks in more evenly

At least a common theme (in the opinions of people who appear to know their stuff) is that mineral oil (car engine oil) is never to be used and will attack the leather.

So there is indeed a reasonably solid basis for that Nissan technical person specifying "olive oil" (and I'm probably not correct in judging it as "an error"). (It appears to me that any animal or vegetable oil can be experimented with for use as a "leather dressing".)

However our needs are considerably different to those of someone with a saddle, holster, or pair of leather boots. (Many of these people prefer to rub in some fat or a paste - such as Dubbin or NIKWAX which is what I use on my leather tramping boots in preference to using any oil at all.)

The oil-application hole on the governor of my B-engine sits directly above the bulged-out-side of my very-soft leather diaphragm. So drips I apply through this hole fall directly on the top of the diaphragm and immediately soak in, gradually spreading their wetness all around it (without pooling anywhere to be able to form any gum). This is how I imagine my Neatsfoot oil behaves and I've replaced diaphragms 2 or 3 times now and have seen ample visual evidence to support this belief.

And Neatsfoot Oil is made from cattle where leather comes from too....

So I'm certainly not willing to experiment with alternatives to Neatsfoot.

I reckon my bottle here holds enough oil to keep 37 million diaphragms nice and soft :

 

[handcannon]

Some excellent information you've dug up there Tom. Makes me wonder about the conclusions drawn by Philip, and the use of Neatsfoot oil on the leather diaphragm. Also makes me want to do more checking up on the use of vacuum pump oil, and what the base is for that oil. Time for me to go to bed now. Hopefully I will remember all this tomorrow morning, and follow up on my questions.

Don

 

[handcannon]

I've been spending some time checking out different oils. The whole spectrum of oils is so diverse that it is definitely confusing. Hydraulic oils and vacuum pump oils often have the same base, but not always. The spectrum spreads from petroleum based oils, to natural based oils such as rapeseed oil.

The following is from Wikipedia.

"Neatsfoot oil is a yellow oil rendered and purified from the shin bones and feet (but not the hooves) of cattle. "Neat" in the oil's name comes from an old English word for cattle.[1] Neatsfoot oil is used as a conditioning, softening and preservative agent for leather. In the 18th century, it was also used medicinally as a topical application for dry scaly skin conditions.

"Prime neatsfoot oil" or "neatsfoot oil compound" are terms used for a blend of pure neatsfoot oil and non-animal oils, generally mineral or other petroleum-based oils."

So, Neatsfoot oil can be all natural, or a compound of natural and petroleum. Hydraulic oil is usually a petroleum base, but can be a natural base. Vacuum pump oil, which is much more highly refined than hydraulic oil, is often a petroleum base, but can be natural base more frequently than hydraulic oil.

My conclusion after all that reading is that the subject of oils is extremely diverse and deep. Before anybody can unequivocally say that one type of oil MUST be used over another type of oil the base of the oil, and the reaction to the item being lubricated, MUST be known. To say that Neatsfoot oil is the only oil to be used on something like the B series motor leather diaphragm, or the SD-22 leather diaphragm, may be incorrect. The base, natural or a blend with petroleum, MUST be known. Also, to say that a hydraulic oil must NEVER be used on the diaphragm may be incorrect.

What MUST be specified is, does a fully natural oil or petroleum oil have to be used for the specific application.

My suspicion is that a fully natural Neatsfoot oil needs to be used on the leather diaphragm. Or, a fully natural type hydraulic oil is also good to be used on the leather diaphragm.

My next project, in addition to everything that needs to be done around this acreage today, is to dig into the subject of how the leather for these diaphragms is tanned. That answer could have a major impact on the type of oil that is safe to use on these diaphragms.

Well, off to the many other things that have to be done today. Hmmmm, what should i do first?

Don