I found my Geno's high flow banjo bolts, so I now have everything I need to swap the pump with a piston pump.

My diaphram pump is now leaking pretty badly, and I'm surprised it hasn't quit.

Any gotcha's I need to avoid?

 

Don't overtighten the banjo bolts. Be careful of the return line when trimming the tappet cover insulation, especially if using a Dremel. The return line runs right above the insulation, so it would be easy to hit and damage.

 

Excellent tips, thanks Dave.

 

Dave summed it up well. I just did mine today, I found it was easier to cut the tappet insulation with a utility knife, it`s kinda cramped down there. Took me all of 3 hours, working easy/slow.

 

Did you use a utility knife?

 

I worked fast and dirty, it took less than an hour. The utility knife is the way to go IMO.

 

You need high flow banjo bolts for the piston pump swap?

 

You don't have to have them, but it would seem like a waste to put a high volume lift pump and leave the restrictive stockers in there!!!

 

If you look in the tech article for the P pump install it shows drilling out the hole in the banjo bolt to increase the flow. This should be almost as effective.

 

That's what I thought also until I compared the two. The holes are HUGE in the Geno's BB's. I also bought the tapped bolts so I can mount a mechanical fuel pressure gauge.

 

I drilled the banjo`s out to 11/64 as per BC847`s awesome writeup. The hardest part of the whole deal was getting the old gasket off of the block. Old style asbestos gaskets tend to turn to stone after a while. So far I`m pleased, the truck definitely runs better,and the smell of fuel is gone (I think the old pump might have been weeping a bit) well worth the time and $$.

 

As it is along with the discussion, I will stick in this question.

Would it be do-able to eleminate the banjo-bolts, entirely, in favor of hose-barb fittings and plain old flexible fuel line??

Are the banjo-bolt threads the same as pipe thread??

Do the banjo bolts have any advantage over plain old fuel hose barb fittings??

Thanks.

 

I can't anwer all of your question but the pipe thead is tapered thread so no...........it could be atraight pipe(banjo bolt) or it could be metric

sorry that really didn't help much at all

 

the banjo`s are a 12by?mm thread (I forget the the thread pitch). I think you would have to tap the fittings to a pipe thread.

 

underpsi converted his--check out his gallery and maybe shoot him a pm if he doesn't read this.