kiki injection pump diaphragm DIY replacement?

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.

Moderators: plenzen, Nissan_Ranger

Post Reply
hevury
Posts: 5
Joined: 11 months ago

kiki injection pump diaphragm DIY replacement?

#1

Post by hevury » 11 months ago

my dad has what I believe to be a 1984 Datsun pickup and the diaphragm in the injection pump went bad so we had to put the truck down until we can find a cheap or usable replacement since they are rare as hen's teeth. but looking at the bad one i wondered if there would be a way to tear it apart and replace the leather with rubber, or similar flexible material to make it work again. I found a source in Germany that i can get a replacement for $10 but it cost about $70 to get it shipped from Germany do to customs . im assuming its so expensive and rare because the EPA frowns upon it being alive. ive been googling and searching this forum for over a month now and if i missed a post with an answer my bad but i figured id ask and if no strait forward answer id try and make one with the old one anyways. no when talking to me make sure to use dumb terms since im not a diesel engine expert. but i do understand there functions. Thanks ahead of time!

waynosworld
Posts: 502
Joined: 7 years ago
Location: Vancouver Washington USA

Re: kiki injection pump diaphragm DIY replacement?

#2

Post by waynosworld » 11 months ago

What makes you think the diaphragm is bad, did you pull it and see a crack/hole in it?
Did you check the rubber vacuum line going to the injection pump to make sure it is not cracked?

I have 2 boxes with numbers on them, here they are

Zexel 9 421 610 043-753
_____682___________961______The 682 is under the 9 and the 961 is under the 753, both in smaller print, the -753 is also in small print.
1 55020-7920 0102f

The other one is for a Mercedes MW pump which fits a SD22

Flag 81 1382
1 420 503 903
K00410019-1210

This is all I have, I am not sure which numbers are the part numbers, neither box says what the part is on the box.
I know the voices are not real,
but they have some really good ideas.

hevury
Posts: 5
Joined: 11 months ago

Re: kiki injection pump diaphragm DIY replacement?

#3

Post by hevury » 11 months ago

the center part of the diaphragm is practically detached from the outer part i can fit three fingers through the hole. hoses are all good and fine. do you have the diaphragm or just the part number because I have the part number list and cross-reference? if you do have an extra what would you want for it? since I know it comes as a whole unit im going to be tearing it apart today and seeing if it is possible to reuse the parts and make a custom form to form some neoprene and make my own diaphragm to reinstal into the original ring and center. i have acess to a lathe mill and many other machine shop tools so in not worried if i have to remake the center pin if i have to drill it out to get the diaphram out. If it comes apart ok i'll try making a trapezoidal press to heat shape the new diaphram and see if i can make one or not. since they are so sparcly found it be good to know if it works or doesn't work.

hevury
Posts: 5
Joined: 11 months ago

Re: kiki injection pump diaphragm DIY replacement?

#4

Post by hevury » 11 months ago

part numbers for the diaphram are

BOSCH 9 421 610 043
ZEXEL 155020-7920
NISSAN 1922576200

with a diagram of the parts here

https://fuel-inject.com/diaphragm/zexel ... 421610043/

and i could not find a supplier in the us that was a good price.

waynosworld
Posts: 502
Joined: 7 years ago
Location: Vancouver Washington USA

Re: kiki injection pump diaphragm DIY replacement?

#5

Post by waynosworld » 11 months ago

I have 2 brand new diaphragms, but I will not sell them, the boxes are what I got the numbers off of, I have several SD series engines so I collect parts when they are available.
All you need is the diaphragm, every one of these parts I have ever seen just came with what is in my photos below.
012.JPG
012.JPG (801.87 KiB) Viewed 1394 times
014.JPG
014.JPG (823.32 KiB) Viewed 1394 times
I have an old used one in an old injection pump I have, I have no idea if it is good or not, below are photos of it.
016.JPG
016.JPG (815.04 KiB) Viewed 1394 times
017.JPG
017.JPG (814.67 KiB) Viewed 1394 times
You can see in the photo below that I threaded the hole in the center, I did not drill the hole, I just threaded what was there, I had planned on trying to make the injection pump manually controlled so I could turbocharge it, but I figured out how to turbocharge it without changing anything on the injection pump.
018.JPG
018.JPG (788.08 KiB) Viewed 1394 times
I cannot see any holes in this diaphragm, and it is soft(not dry) and appears to move fine, I suppose I would take $30.00 shipped USPS flat rate box to the lower 48 states, I cannot guarantee this part as it is an old used part, all I can say is it is soft and pliable.
Have you tried a diesel injection shop where they rebuild these pumps?
I know the voices are not real,
but they have some really good ideas.

hevury
Posts: 5
Joined: 11 months ago

Re: kiki injection pump diaphragm DIY replacement?

#6

Post by hevury » 11 months ago

the used one would be too risky. since I plan to daily this truck if I can get it fixed. we tried local shops with no good answer and that's why I went to see if I can form my own. if I succeed it might be a good way to make a little extra cash by repairing broken ones. I managed to get the whole diaphram apart without destroying anything to bad and im going to machine a press form to make a new diaphram out of neoprene or likewise rubber. and see if I can reassemble it well enough to work well.

User avatar
asavage
Site Admin
Posts: 5346
Joined: 14 years ago
Location: Duvall, Wash.
Contact:

Re: kiki injection pump diaphragm DIY replacement?

#7

Post by asavage » 11 months ago

From a previous discussion, 13 years ago:
Image

If you can rebuild the pneumatic governor diaphragms, you'd have a captive (though shrinking) market.

While they do tear, if proper addition of the diaphragm lubricant is applied regularly, they do seem to last pretty well.

Old discussion about cod liver oil and replacement lubricants for the SDxx pneumatic governor diaphragm.
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.

Nissan_Ranger
Posts: 264
Joined: 13 years ago
Location: Canada

Re: kiki injection pump diaphragm DIY replacement?

#8

Post by Nissan_Ranger » 11 months ago

My old Ranger with the SD-22 transplant is still running the same power steering fluid that I installed in the injection pump 15 years ago. Works fine...
The old 'six gun' was as popular as the cell phone in its time and just as annoying when it went off in the Theater.

hevury
Posts: 5
Joined: 11 months ago

Re: kiki injection pump diaphragm DIY replacement?

#9

Post by hevury » 11 months ago

i had fair luck taking the whole assembly apart and if i can get a system for forming a diaphram rubber I should be set for making one. the aluminum ring on the outside was slightly mangled getting it uncrimped so i may have issues using it but if I can get the orientation of the diaphram right i should be able to make a seal without the ring on the outside. possibly using an o ring as a sealing spacer in the recess for the ring.
Attachments
53352584_426841131385992_6288183591402733568_n.jpg
53352584_426841131385992_6288183591402733568_n.jpg (308.56 KiB) Viewed 1370 times

waynosworld
Posts: 502
Joined: 7 years ago
Location: Vancouver Washington USA

Re: kiki injection pump diaphragm DIY replacement?

#10

Post by waynosworld » 11 months ago

I hope it works out for you.
I know the voices are not real,
but they have some really good ideas.

BarryLaX
Posts: 6
Joined: 7 months ago
Location: United Kingdom
Contact:

kiki injection pump diaphragm DIY replacement

#11

Post by BarryLaX » 7 months ago

thats what the technition told me to set it at for the pumps state of tune
is it possible to get the pump 360 out?
thanks
Jeremy

Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest