1993 7.4L/Bravo 1 - Sea Water/Fuel Pump

[FuelishBehavior]

Over the weekend, the actuator lever on my fuel pump was worn down to the point of no fuel pressure so the engine starved for fuel. The culprit, no gear lube in the fuel pump provision at the sea water pump. I have removed the pumps, the fuel pump will have to be replaced. However, the sea water pump still rotates but it doesn't seem to be perfectly smooth and the slip ring that rides on the lobe/shaft shows significant wear. Since a new sea water pump is $600+, I'm thinking of just rebuilding it by changing bearings and seals along with new slip ring and pray that the shaft/lobe is fine. My questions are this, has anyone ever rebuilt one of these units and do you have any tips/info on this?

Secondly, fuel pumps are upwards of $150 to $200. However, Airtex Part No. 60932 seems to be a direct "marine" replacement for these pumps and are about $50. Has anyone had any experience with these fuel pumps?

 

[alldodge]

Re: 1993 7.4L/Bravo 1 - Sea Water/Fuel Pump

Never replaced the bushings or cam in the housing but doesn’t appear to be that difficult if you have the right size puller/press. I have replaced all the brass bodies with the composite style years ago and was well worth it. The composite housings make it much easier to replace the impeller.

In research of the Airtex fuel pump I have only found a few grumblings but most all folks say its great. On offshore only a guy there says he looked at one with the Mercruiser dealer and it had Airtex and the part number on it. Seams to put out more than enough fuel and will work fine.

 

[04fxdwgi]

Re: 1993 7.4L/Bravo 1 - Sea Water/Fuel Pump

Over the weekend, the actuator lever on my fuel pump was worn down to the point of no fuel pressure so the engine starved for fuel. The culprit, no gear lube in the fuel pump provision at the sea water pump. I have removed the pumps, the fuel pump will have to be replaced. However, the sea water pump still rotates but it doesn't seem to be perfectly smooth and the slip ring that rides on the lobe/shaft shows significant wear. Since a new sea water pump is $600+, I'm thinking of just rebuilding it by changing bearings and seals along with new slip ring and pray that the shaft/lobe is fine. My questions are this, has anyone ever rebuilt one of these units and do you have any tips/info on this?

Secondly, fuel pumps are upwards of $150 to $200. However, Airtex Part No. 60932 seems to be a direct "marine" replacement for these pumps and are about $50. Has anyone had any experience with these fuel pumps?

1st. Yes, the parts (bearings and seals) are available to rebuild the housing. I did mine last year due to the fuel pump failing and diluting the oil.

Pump end seals	Mercruiser 26-90562 Qty 2 $9.95 ea
Pulley end seal	Mercruiser 26-806930 Qty 1 $13.95
bearings	Mercruiser 30-72961 Qty 2 $8.95 ea
Shaft	Mercruiser 818366A Qty 1 $79.95

2nd. The Airtex pump (that's the one I used) is indeed a direct replacement for the Mercruiser one. paint it black and there you have it. ( May even be MC's OEM supplier. Airtex or Carter). I got mine a Rock Auto. The screws, fitting, placement positions, everything are identicle to the OEM piece.

You can get a loaner pulley puller from one of the big chain auto parts houses to do the pulley. Don't try to brute force it or you'll destroy it pretty easily. The pulley is the hardest part of the whole operation.

The Mercuiser manual 15 has a step by step proceedure on how to do it, starting on page 6A-18. Manual 16 has it starting on 6A-13.

 

[FuelishBehavior]

Re: 1993 7.4L/Bravo 1 - Sea Water/Fuel Pump

Thanks for all the info gentlemen. I have already downloaded the manual regarding the procedures and I have all the proper pullers and presses so I guess I'll start the process tonight. One quick question regarding the slip ring however. Does the slip ring just ride on the lobe and why wouldn't you just have the fuel pump ride directly on the shaft lobe. Is this some kind of wearing mechanism?

 

[04fxdwgi]

Re: 1993 7.4L/Bravo 1 - Sea Water/Fuel Pump

Thanks for all the info gentlemen. I have already downloaded the manual regarding the procedures and I have all the proper pullers and presses so I guess I'll start the process tonight. One quick question regarding the slip ring however. Does the slip ring just ride on the lobe and why wouldn't you just have the fuel pump ride directly on the shaft lobe. Is this some kind of wearing mechanism?

When I opened it up and saw that slip ring, it surprised me too. It just sort of sits there, flopping around. But I guess that by the sheer nature of it, it works kind of like a bearing surface if the oil is good. It just sort of works and I didn't try to "over think" the whole idea.

 

[tpenfield]

Re: 1993 7.4L/Bravo 1 - Sea Water/Fuel Pump

I got the sea water/fuel pump combo on my boat, So I'll be following this thread just in case I need to do the same someday.

I already replaced the fuel pump on the starboard engine, because the surveyor checked it during the pre-purchase process and you could immediately smell gasoline in the oil well of the pump cam. I spent the upwards of $200 for the pump . . . oh well.

 

[FuelishBehavior]

Re: 1993 7.4L/Bravo 1 - Sea Water/Fuel Pump

I used a pulley puller and some PB Blaster to remove the pulley. It pressed off no problem. Remember that there is a required depth of 1/2" from the pulley edge to the shaft for rebuilding. It probably would be prudent to measure this first. I did and mine was the specified 1/2". I then used a screw driver to pull the outer seal off which revealed the snap ring. Using a pair of snap ring pliers I removed it. Then I just gave the shaft on the other side a little whack with a plastic mallet and the shaft and outer bearing with slip ring and washer slid right out. I then removed the quad seals from the other side. I then put the housing in my press and pressed the remaining bearing out through the housing. You just have to be careful removing this bearing and make sure you press it through straight. Now I have an empty housing and shaft to clean. I will order new bearings, slip ring and seals and rebuild the pump for $75. This is a cost savings of nearly $550 to $600 after tax and shipping. I would say if you're only even somewhat mechanically inclined this is a repair that if needed is well worth the savings to do it yourself. I'm surprised someone hasn't done a youtube video of this.

I will post pictures of the parts laid out and a step by step with photos on the rebuilding process. If you have the right tools, screw drivers, punches, and an 8 to 12 ton press this isn't as bad a job as it seems. One could probably even do it without the press by using a vice creatively.

Thanks for all the help fellow mariners. And yes, that slip ring is odd as all get out! Don, can you shed any light on what the heck this part's actual job in life is?