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Fuel Pump

Posted: January 21st, 2021, 4:25 pm
by abcoker
The Fuel pump went out on my starboard 1993 Crusader XL. I ordered this part from Amazon

I installed the pump and the engine starts and runs great, but I couldn't get the fuel line connectors to stop leaking. I took it apart and put it back together 5 times with different amounts of torque on the nuts and Loctite on the threads, but it would always leak fuel between the hole in the nut where the fuel line passes through.
The last time I took it apart, i broke one of the fuel lines CRU98148 #22 in the diagram

My plan was to just replace everything from the fuel filter housing forward including an OEM fuel pump, but I can't find the parts.

Can these fuel lines be replaced with flexible ones?
Does anyone know a good source for these parts?
Any advice on how to make those connectors not leak?

Thanks,

Re: Fuel Pump

Posted: January 21st, 2021, 5:09 pm
by bud37
The issue I have found for myself is the need to match the reverse flare angles.....that may be the issue with the leaks.....

Re: Fuel Pump

Posted: January 21st, 2021, 6:24 pm
by tomschauer
Its possible that the new pump has standard NPT (tapered) threads and your old fittings are SAE (straight) threads with a reverse flare as mentioned above. This will never seal, at least not in such a way I would ever trust with gas.
Compare the old pump fittings to the new pump fittings.
You probably need to change whichever fittings are easiest to change, the lines or the pump.

Re: Fuel Pump

Posted: January 21st, 2021, 10:29 pm
by Viper
I can never get Amazon links to work. Is it an OEM replacement part or aftermarket?

I think the standard now is that on board fuel system lines (on the engine) are supposed to be metal after the fuel filter.

Re: Fuel Pump

Posted: January 21st, 2021, 11:12 pm
by abcoker
its an aftermarket fuel pump. admittedly pretty cheap.

There are fittings that screw into each end of it. I didn't get new ones so I used the original. It does not appear to be leaking through those threads but through the reverse flare connection.

The reverse flare connection is the original parts that didn't leak before but do now.

I have been totally frustrated with this repair so I decided to spend the money and just buy all new stuff from the filter forward, but can't find the parts. Especially after I broke one of the fuel lines.

Re: Fuel Pump

Posted: January 22nd, 2021, 9:21 am
by tomschauer
The fittings on the pump do not have anything for the flare to seat against. They are tapered pipe thread fittings (NPT).

Re: Fuel Pump

Posted: January 22nd, 2021, 10:18 am
by km1125
Is it possible your old pump had a adapter to change the tapered thread to a reverse flare and that didn't get moved over to the new pump? Look inside the fitting to make sure there's a reverse flare inside before putting the tube on it.

The key to tightening reverse flare fittings is first to make sure they are CLEAN. any dirt in the flare can affect its ability to seal. Then, as you're putting the connection together, only tighten the nut by FINGERS while you wiggle the pipe. Do this on both ends until they are completely finger tight, THEN use a wrench. They do not have to be wrenched so tight they'll never come off again either.

Re: Fuel Pump

Posted: January 22nd, 2021, 10:47 am
by abcoker
km1125 wrote:Source of the post Is it possible your old pump had a adapter to change the tapered thread to a reverse flare and that didn't get moved over to the new pump? Look inside the fitting to make sure there's a reverse flare inside before putting the tube on it.

The key to tightening reverse flare fittings is first to make sure they are CLEAN. any dirt in the flare can affect its ability to seal. Then, as you're putting the connection together, only tighten the nut by FINGERS while you wiggle the pipe. Do this on both ends until they are completely finger tight, THEN use a wrench. They do not have to be wrenched so tight they'll never come off again either.


I feel like I did that multiple times in every way.

Re: Fuel Pump

Posted: January 22nd, 2021, 11:25 am
by bud37
Situations like this are becoming more common, offshore fittings are not made that well ( some are ), the threads are just not made to the correct specs ( root depth etc ), angles are off, even the pipe threads are rolled badly...then you throw in metric...... :-O ..

I can say this has created many leaks for me with brand new parts.....sometimes you have to be very diligent to get the right part to fit correctly especially with fuel fittings because they can bleed fumes even though there is no visible leak even with high quality AN fittings.

Probably just a part match thing here.