whats the easiest way to get the lift pump off?

SD diesels were widely available in the US in the 1981-86 Datsun/Nissan 720 pickups, and in Canada through '87 in the D21 pickup.

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Glegor
Posts:23
Joined:10 years ago
whats the easiest way to get the lift pump off?

#1

Post by Glegor » 9 years ago

i wanna take the lift pump off my inj pump, i got my truck running, but it sucked some crap up, or has a stuck check valve in the lift pump/primer.

is it easier to take it off with the 2 small bolts, or the one big nut on the outside?

anyone have any other advise for me?

btw, like i said, finally got it running, and boy, does it idle nice, not hardly any blow by either.

but you pretty much have to use the glow plugs to start it. is that normal on these?

my VWs only need the plugs to start cold.

charmalu
Posts:166
Joined:10 years ago
Location:Soquel, Calif

#2

Post by charmalu » 9 years ago

I`ll have to take a look at mine in the morning, 12:25am now, little dark out side.

All the years I have owned mine, I have had to use the Glow Plugs. even when it is warmed up or she won`t start. or at least what my Foggy old brain remembers.

Charlie
82 Datsun KC 483K lost #2 cyl blowing blue smoke :cry:
83 Nissan LB 134K SD-25 as of 10-21-13
78 240D Mercedes $300 Parts?
80 240D 360K
80 240D Parts? $750
82 240D Parts? $440
84 300SD 270K
85 300D 363K
86 Ford F250 6.9 Diesel 221K

Glegor
Posts:23
Joined:10 years ago

#3

Post by Glegor » 9 years ago

yea, it was nuts, the head was hot to touch, and it would not fire without a few seconds of glows.

and thanks for looking for me.

nothing spring loaded in there to come flying apart once i start loosening things, right?

charmalu
Posts:166
Joined:10 years ago
Location:Soquel, Calif

#4

Post by charmalu » 9 years ago

No, no springs clips etc to fly out.

there is the one nut on top, and two on the under side. look lke they are 10mm. might be able to reach from under the truck. I haven`t pulled one off these engines. Pulled off a mercedes 617 engine. same bosch pump design. they are a PITA to get to as I remember.

there should be a "O" ring on the part that fits into the IP. so nothing to fly out. Did your lift pump quit? just wondering why you are removing it.

There might be a rebuild kit for these pumps.

Charlie
82 Datsun KC 483K lost #2 cyl blowing blue smoke :cry:
83 Nissan LB 134K SD-25 as of 10-21-13
78 240D Mercedes $300 Parts?
80 240D 360K
80 240D Parts? $750
82 240D Parts? $440
84 300SD 270K
85 300D 363K
86 Ford F250 6.9 Diesel 221K

Glegor
Posts:23
Joined:10 years ago

#5

Post by Glegor » 9 years ago

i think it just sucked up a chunk of junk from the pump. ive got a primer pump supplying pressure to the inlet of the pump, thinking it might just be tired, but it will not flow at all.. i know it used to work. used to be able to prime the pump with the primer. now nothing at all..

charmalu
Posts:166
Joined:10 years ago
Location:Soquel, Calif

#6

Post by charmalu » 9 years ago

Do you have the old style primer pump? the one you have to unscrew, and it pops up, then pump it till primed and push down and screw it tight?

Mine gave me some problems, then rusted in place. a lot of these will suck air after while and give you fits. I replaced mine with one of the new Bosh little short black ones. nothing to unscrew, just push it, and all primed. they are around $20.

This could be your whole problem.

Do you have a filter before the lift pump?

Charlie

I found this thread on Lift pumps. this might answer some of your questions.
http://nissandiesel.dyndns.org/viewtopi ... ght=primer

Charlie
82 Datsun KC 483K lost #2 cyl blowing blue smoke :cry:
83 Nissan LB 134K SD-25 as of 10-21-13
78 240D Mercedes $300 Parts?
80 240D 360K
80 240D Parts? $750
82 240D Parts? $440
84 300SD 270K
85 300D 363K
86 Ford F250 6.9 Diesel 221K

Glegor
Posts:23
Joined:10 years ago

#7

Post by Glegor » 9 years ago

unscrewed the inlet banjo bolt..

found a little screen inside there. it was clogged REALLY BAD..

cleaned it and put it all back together, primed it up, and it fired right up and ran perfectly. starts nice and easy, even with an old GR starter.

im gonna extract the transmission tomorrow, and pull the front case half off, and install a gasser gearset..

im willing to bet that i have one of the cheapest, ugliest datsun diesel pickups on the forum :lol:

oh yea, do these trucks take a special clutch slave cyl? i might have to buy a new one..

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asavage
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#8

Post by asavage » 9 years ago

I don't think that the clutch slave is special.

On the earlier 720 diesels, there's a hydraulic damper inline to the slave cyl., which the gassers didn't get until a few years later ('84? '86?). The pic below is an '86 gasser, and the damper is directly below the wiper motor.

Image
Regards,
Al S.

1982 Maxima diesel wagon, 2nd & 4th owner, 165k miles, rusty & burgundy/grey. Purchased 1996, SOLD 16Feb10
1983 Maxima diesel wagon, 199k miles, rusty, light yellow/light brown. SOLD 14Jul07
1981 720 SD22 (scrapped 04Sep07)
1983 Sentra CD17, 255k, bought 06Jul08, gave it away 22Jun10.

charmalu
Posts:166
Joined:10 years ago
Location:Soquel, Calif

#9

Post by charmalu » 9 years ago

I have that clutch dampener on my 82. I always wondered if it was all that usefull. thing has been there for the past 463K miles, and probably wore out.

My 2 Mercedes, 240D and 300D don`t have a dampener. Just a line from the MC to the Slave.

Charlie
82 Datsun KC 483K lost #2 cyl blowing blue smoke :cry:
83 Nissan LB 134K SD-25 as of 10-21-13
78 240D Mercedes $300 Parts?
80 240D 360K
80 240D Parts? $750
82 240D Parts? $440
84 300SD 270K
85 300D 363K
86 Ford F250 6.9 Diesel 221K

User avatar
asavage
Site Admin
Posts:5351
Joined:15 years ago
Location:Duvall, Wash.
Contact:

#10

Post by asavage » 9 years ago

Well, Nissan later added it to the gassers, so presumably they were trying to fix something ;).

Glegor
Posts:23
Joined:10 years ago

#11

Post by Glegor » 9 years ago

we eliminated the damper off my buddies 85 nissan, and off my cousins 86 4x4..

both trucks still worked great after that.

that clutch damper just seems like somewhere for air to get trapped and not easily bleed out.

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