'82 720 kc w/sd22, vacuum pump line

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720guy
Posts: 5
Joined: Sun Oct 18, 2015 8:21 am
Car: '82 720 kc 2wd w/sd22 diesel

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Hi, In the course of replacing the alternator on my '82 720 kc with the diesel sd22 engine, I damaged the line from back of vacuum pump (which is mounted on the back of the alternator, GREAT design!) to block. Now it leaks oil at the swivel(?) fitting at the block. I've looked for parts, diagrams of the vacuum system, engine, etc., to no avail.
1) Does anyone know the name of the part, and/or have an exploded parts diagram for it, so I can get one?
2) Does anyone have the part to sell, or preferably give, to me?
3) Does anyone know where I can get one?
4) Does anyone know if it can be fixed or fabricated?
5) Is it a vacuum line or oil line?

Will post the a picture once I figure out how.


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waynosworld
Posts: 232
Joined: Mon Aug 24, 2015 11:10 pm

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That is a return line for the oil going into the vacuum pump, it is not under any pressure, so when you transferred the vacuum pump to the new alternator you either cracked the line or the vacuum pump itself came apart and was not put back together correctly, as I recall there is an O-ring in there that could come out of its groove.
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You can see in this photo that the hose is held on with clamps.
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Remove your hose, go to the parts store and look thru there inventory till you find something the right size with the bends in the right place that you can make work, if you have to, you could likely use a straight hose and bend it, but it gets hot down there, so find something close if you can.
You need to figure out for sure where the oil is leaking from, it could be just a loose clamp also.

720guy
Posts: 5
Joined: Sun Oct 18, 2015 8:21 am
Car: '82 720 kc 2wd w/sd22 diesel

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Thanks for the reply. Unfortunately that's not the hose that is leaking. I have tried to upload a picture to no avail. The line I damaged comes from the center of the vacuum pump to a nipple in the block and is about 6" long. It has a male fitting (17 mm wrench size) that threads into the vacuum pump and a female swivel fitting (14 mm wrench size) that threads onto a male nipple on the block. The upper right corner of your second picture shows a glimpse of the connection to the block. I damaged the little tube that extends out from the female fitting.

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waynosworld
Posts: 232
Joined: Mon Aug 24, 2015 11:10 pm

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OK, that is the oil feed for the vacuum pump, you need to remove that line from the block first, then remove it from the Alternator, then take it to a Hydraulic hose repair place and have them make you a new one.
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Put it back on the alternator first, then put it on the block fitting, as the block fitting is a special type of fitting made to install it just that way.

720guy
Posts: 5
Joined: Sun Oct 18, 2015 8:21 am
Car: '82 720 kc 2wd w/sd22 diesel

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That's it. Thanks! Took it to a hose repair place. Will report back when I install the new one.

720guy
Posts: 5
Joined: Sun Oct 18, 2015 8:21 am
Car: '82 720 kc 2wd w/sd22 diesel

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Forgot to mention that I tried to get one at the Nissan dealership. They don't stock the part any more.

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waynosworld
Posts: 232
Joined: Mon Aug 24, 2015 11:10 pm

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Nissan is likely not the best place to look for that part anymore, but the forklift shops might have that part, as forklift engines had that vacuum pump on the alternator also, so they must have had power brakes, there are still a lot of Datsun forklifts out there.
I bought a SD25 diesel engine in the past 3/4 years from a shop that had forklifts, the company went out of business, and sold off all it extra stock and equipment, they had an extra forklift engine for backup that I stole for $1275.00 on ebay, I still can hardly believe I got it for that.

720guy
Posts: 5
Joined: Sun Oct 18, 2015 8:21 am
Car: '82 720 kc 2wd w/sd22 diesel

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Got the replacement line back from the hose repair place and installed it. Works well.


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