Fuel Pump rebuild - diaphragm replacement

[19692000survivor]

I removed my fuel pump on my 1967.5 2000 for rebuild.
I have done this before with not too much trouble on my 1969 but I guess no 2 cars are alike so here we go with the problems I had.
The 1st issue was that I couldn't remove the pump once unbolted - it didn't have enough clearance and hit on the frame as I tried to pull it off the studs (I have the long studs on this car) I ended up loosening the passenger side motor mount and raising the engine up allowing it to clear and remove.
Disassembly - not a big deal as learned on my 1969 experience after using my palm to press and twist the pin out of the locked position unsuccessfully I simply removed the old diaphragm by using a bench grinder to grind off the head on the diaphragm's plunger pin allowing the center plate to separate & pop off. Once the diaphragm's center plate,spring and center seal were removed I could easily just push the pin in unlock and remove it.
Now for my unresolved problem I cant get the new diaphragm to lock back in place I know on my 1969 it took a lot of tries before it finally latched in but the 1967.5 is a bear.
I have the short pump arm so this pump should be a rebuild able pump.
I have gotten it to catch twice but never completely locks in at 90 degrees when twisting it.
Does anyone have any tricks or techniques they have learned with replacing these?
Thanks, Rick

[Linda]

Do you have a pic?
Linda
Try pushing the foot in as far as possible, while simultaneously pushing down on the diaphram and twisting it, then release. Not sure if that is what I did, but worth a try.

[Gars68]

http://www.datsunroadster.com/PIC_PAGES ... 170-06.htm

This info may be helpful compliments of Rallye.

[19692000survivor]

Thanks but I wasn't able to open the file link from Rallye.
Here are a couple of pics to show the pump's diaphragm pin and locking latch position internal to the pump.
The 2nd picture shows a gold colored cover that snaps into the center the 1st picture is with that gold cover removed for view of where the pin locks into place. It looks like the right side latch arm is shorter to allow the pin to twist the left side is the one that's hard to get the pin to twist into to lock.
Any suggestions or tricks to make the pin latch other than more pushes & twists until I get lucky?
Thanks, Rick

[19692000survivor]

I don't know if anyone has looked at these yet but any suggestions after pictures were added to my post?

[spl310]

Prayer and hard liquor?

[Linda]

I did. What happens when you push on the lever? Can you see it open up in there? If so that is when I believe you push the diaphram T in and turn. Also the rubber tab is usually at the back 180 deg from the lever, and all the holes line up.
I think when you press the lever it simulates the "over travel" warned about when not using a spacer between the pump and block when installed. Must have the spacer block. But when you push on the lever on the bench, it may open up the internals to allow the T diaphram to be installed.
Per Rallye some of the longer lever fuel pumps can be rebuilt, some not.
Pic of the lever therefor is helpful.
Linda

[19692000survivor]

Linda,
Here is a picture showing the lever on my fuel pump.

DSC01986.JPG

[Linda]

So that is a late pump, which according to Rallye site, some can be rebuilt and some can not. I don't know how you tell. However I recall a few people saying if you press out the pin in the lever you can rebuild anything I have never done it and may be problematic or too much work for most versus getting a new pump. There are some aftermarket pumps that vendors have too.
Others may have some insight as well
Did you try pushing on the lever firmly while inserting the diaphragm?
Linda

[19692000survivor]

Maybe I am not holding my mouth right yet I can get the right side (short latch) to lock in occasionally but not the left side. .
Looks like I might be buying a pump. At least that's the quick and dirty solution - pay the man & move to the next thing on the list.
Linda, Thanks again for your help and support on this adventure as well as several others that you have helped me with.
Rick

[Linda]

No problem, Rick
Wish there was someone local to help out.
On those longer pump studs, just unscrew them til the pump comes off, and the reverse to install, then no need to mess with the motor mount.
Linda

[ppeters914]

Awake old thread! Awake!

I have 3 fuel pumps from various R16's. One of them looks old style, i.e. shorter, stamped/squarish lever arm, thin mounting flange. The other two have the longer lever arm and thicker mounting flange, so guessing they're the newer style.

roadster fuel pumps.jpg

0
Trying to take one apart (newer, best condition) for vapor blasting. I can rotate the diaphragm easily, but it doesn't disengage. Can I assume this is the newer, probably-not-rebuildable pump? Tried removing the lever pin, but tapping either end with punch does nada.

Any additional words of wisdom or insight?

Thanks.

[jrusso07]

I have rebuilt a few of these. Some have the t-end on the diaphragm post, some have a bulb end with a clip the goes on the bulb and holds it to the arm. The latter may have been for L series as they look pretty much the same. I just dont recall as I did this many years ago.

You do have to engage the pump spring arm to get the diaphragm out and back in. Rubber tab 180 from the pump arm. There is some pretty strong spring pressure to over come. Put the fuel pump body in a bench vise.

If it is a t, Be sure the t is perpendicular to the arm as they can come off during use. Seen that.

[ppeters914]

After fighting this thing off and on for days, I finally determined it's a later pump with the "T" diaphragm rod. I can even see which direction the "T" is, however, no amount of twisting, pressing, pulling, etc. will allow it to be removed. I'd just put it all together, but the diaphragm has some serious cracking an wear in the rubber. It might work for a while, then decide to fail when crossing Death Valley.

Hate to do it, but time to call it quits. Besides, I still have 2 other pumps to try!