Page 2 of 6

Posted: Sat Jul 26, 2008 1:36 am
by Gary1945
That looks like many a fuel pump ive installed on many GM's,a 1960 Pontiac 389 Bonniville for sure I owned and it looks to be it. It also fits some Chevys too to be sure. Ask for one and see for yourself. have a good day all. :)

Posted: Mon Jul 28, 2008 9:53 am
by peteybug
Ok it's been a week and going great. Have put a little over 500 mils on the pump. More good news also got a roll of material from a supplier at work. It nitrial rubber, made a couple diaphrams out of it and put it on one of my other bikes and is working good so far. When salesman gave it to me I put a chunk in gas and soaked it for a week. Gas had no effect on it. So may have found stuff that will work for everyone!! If it pans out will be glad to share.

Posted: Mon Jul 28, 2008 10:11 am
by Whiskerfish
Nitrile is probably about the best compund available for this. Does it have any reinforcing web internally?? If it was made corretly Nitrile will not be affected by Gas or any other pet products.

All other Fuel tanks in the Helicopters I worked on had a 60 month life limit. The Nitrile made ones were not a scheduled removal item and were classified as "remove upon condition" this basically meant that they were approved for use indefinetly. The only time I ever saw any fail was when they were punctured or installed improperly.


Chart is from here:

Posted: Mon Jul 28, 2008 12:01 pm
by peteybug
Two layers of nitrile with some sort of string fiber inbetween. The sales man told me he was pretty sure it woud hold up. Only problem I had was I had to strech out spring under the diaphram as this stuff is a little stiffer. The best part is our mill uses this stuff for a barrier between our stack rolls. When the edge of it gets wore down running on a steel roll they toss it. That means Ill get tons of it free!! :twisted: Whitch translates into I'll have a life time supply to share. :-D

Posted: Mon Jul 28, 2008 12:19 pm
by Gary1945
peteybug you have a PM.

Posted: Tue Jul 29, 2008 5:29 am
by WingerDave
Absolutely fantastic respekt2 .

Now i just need to source some of that stuff over here.


Posted: Tue Jul 29, 2008 9:07 am
by peteybug
Winger if this pans out Ill see what I can do about shipping some. Give me some time I would like to find the same stuff only a little thinner. This is thicker than org. The rep from the company said he's sure they make differant thicknes's.

Posted: Thu Jul 31, 2008 1:27 pm
by peteybug
Ok if anyone wants to try a sample let me know. I will mail some out free of charge. I can handle the first 10 request for now. This will be for you to test out. So pm me and I will get back to the ones I can mail to, for now.

Posted: Fri Aug 01, 2008 7:13 pm
by Whiskerfish
Ok I got mine installed. I have to wait a couple of day to check it out as the pump was very nasty looking and needs painted before it goes on my bike. The only challenge I had with the install was trying to keep the post from spinning while I was running the tap down it. I ended up using a 1/8th " drill and a 4 x.70 tap. Matches some surplus float bowl screws I had. I ended up holding it still with a pair of side cutters.

Posted: Sat Aug 02, 2008 9:12 am
by peteybug
:lol: oops forgot to mention that whisker sry I used needle nose.

Posted: Sat Aug 02, 2008 10:18 am
by heraldhamster
Whiskerfish wrote:... 1/8th " drill and a 4 x.70 tap...
I think that's what I picked up yesterday for this same job. and a S/S machine screw to match. won't have time for it this weekend, though.

Posted: Sat Aug 02, 2008 11:31 am
by lcallison
Both my fuel pumps are good and I have a spare. Once you decide on the best product for the diaphragm, post it please with part number and supplier. It would sure be a boon to the rest of us. Great job on figuring this out. I had thought there should be a way to fix them, but hadn't worked much on figuring it out. Kudo's!!!

Posted: Sat Aug 02, 2008 9:30 pm
by Whiskerfish
Ok I been playing with this a good part of the day. I have some issues!!!

Pics Below

First there are 2 different manufacturers of these pumps!! And yes they are different. I installed my pump and got no flow at all. The check valves in the top were good and I got a good siphon through it but no pump action at all. I thought that maybe a shortcut I had taken was the problem. I had cut my screw down to about 1/2 inch and it was too long so I added a couple of washers under the head. It went together fine but I am pretty sure the head clearance against the top of the pump was inadequate for good operation.

So I took it apart again and cut the screw down some more. I was comparing the pumps and realized the the lever that rides on the cam on the one I was working with had a Lot more free movement before I felt any load from the big spring under the Diaphram. So I kept cutting down the screw and checking it. I got to the point that I have no washers at all under the head of the screw and I still have too much freeplay on the lever when the cap is on. I suspect that in the unloaded position the Screw head is hitting the top of the pump cap and that @ 1/8 inch of lost movement is preventing a good flex of the Diaphram. I am kind of guessing that this is the problem right now. Tomorrow morning I will grind off the head of the screw and leave just enough metal to hold things together and try it again. I am expecting a somewhat reduced flow due to the thickness of the material. This stuff measures at about 1.5 mm and the one that came out was 1.25mm.



The pics below are just to illustrate the differences between the 2 different manufacturers



The 2 different caps



Posted: Sat Aug 02, 2008 10:45 pm
by peteybug
I had same problem at first. I think its due to thicker rubber or not molded. I used a small ammont of heat on rubber then put screws in snug. Then worked pump by hand. If you listen to pump you can hear it pump tighten screws and do it again you can here and feel it pump or stop. If it stops loosen and work by hand. Also had to strech spring. it took a few times befor it loosen enugh to put on bike.

Posted: Sun Aug 03, 2008 12:19 am
by Old Fogey
I found a couple of suppliers of NBR sheet over here. Whooo, Not cheap!

However, one supplier will suppy by the metre x1200mm wide, no 1.25 but 1.0 or 1.5mm thick. That would make a lot of diaphrams.

They can also supply Viton sheet which may be better; any thoughts?

Does the original diaphram have reinforcing in it like the ones you've made up?