Lifespan of PCM mechanical fuel pump?

[strad]

Mine works just fine. But it appears to be original, or at least very old. Are these things capable of failing suddenly (as in torn diaphragm or some such)? It is 29 years old. . .

[aquaman]

If you are asking if its smart to replace parts before they break, the answer is Yes.


Its all part of maintenance.

[Cloaked]

Originally Posted by strad

Mine works just fine. But it appears to be original, or at least very old. Are these things capable of failing suddenly (as in torn diaphragm or some such)? It is 29 years old. . .

I have seen them go for a long time. They typically fail without warning. They will fail on a Friday afternoon on a three-day weekend or the beginning of a long vacation or when a good ski day is coming up with a planned sick-day from work.

Auto parts store will not have one and Discount Inboard Marine is closed until Monday.

Your call....

Me? I'd have a new one on there sooner than later.

$0.02

.

[03geetee]

Originally Posted by Cloaked

I have seen them go for a long time. They typically fail without warning. They will fail on a Friday afternoon on a three-day weekend or the beginning of a long vacation or when a good ski day is coming up with a planned sick-day from work.

Auto parts store will not have one and Discount Inboard Marine is closed until Monday.

Your call....

Me? I'd have a new one on there sooner than later.

$0.02

.

What he said! I would buy it now and have it next too your extra coil, impeller, belts and extra raw water pump gaskets and parts. All of the above are weekend enders if the right people are not open, or can get it to you fast enough.

JTR

[MikeyOrange88]

Originally Posted by strad

Mine works just fine. But it appears to be original, or at least very old. It is 29 years old. . .

Ditto for mine, but it's on an Indmar (25 yrs. old). Great question though. I didn't like the 'fail without warning' answer. By that I'm assuming you mean it will just leave you stranded in the middle of the river, etc., and a tow in will be needed (ie. you're not limping home). May need to make a priority out of replacing it in mine now. I was thinking I'd like to just get one and keep on board, but seems some preventative maintenance is in order.

[strad]

yeah I was just asking because I happened to be watching the wheeler dealer show awhile back and Edd (the master mechanic on the show) took apart an old fuel mechanical fuel pump that he had replaced for preventive maintenance, and the diaphragm inside was getting cracked and rotted, and probably would have failed soon. It was as old or older than mine. That was a pump off a different engine than a 351 (obviously) but I assume mechanical fuel pumps must all be pretty similar. . . got me thinking anyways.

Lol I guess I'll get one!

[thatsmrmastercraft]

The fuel pump on my '77 appears to be original and is on the Spring replacement list. I am not going to bother keeping the new one handy - I'm just going to put it on. The first one lasted 36 years so I should be good for another 36.

[east tx skier]

I got 15 years out of the low pressure fuel pump on my PCM GT-40 (this is the one on the outside of the FCC). Just replaced it last month. It was considerate enough to go out (gradually) at the ramp). I've never heard of a PCM fuel pump to fail gradually. It started tripping the 15a breaker and making a nasty noise on prime. It was a short swim back to the ramp with the boat in tow.

High pressure fuel pump is still going strong (as far as I can tell).

[MikeyOrange88]

Originally Posted by thatsmrmastercraft

The fuel pump on my '77 appears to be original and is on the Spring replacement list. I am not going to bother keeping the new one handy - I'm just going to put it on. The first one lasted 36 years so I should be good for another 36.

If yours has lasted that long, then I guess the ethanol fuel must not have much of an effect on the rubber diaphragm. I know Holley makes special accelerator pump diaphragms (aqua colored) for alcohol based fuels, per their website. My last carb. rebuild kit had one in it.

After reading some of the Fuel Pump 101 thread, kind of glad I still have the mechanical unit. Had a couple of the electric fuel pumps go out in trucks, Tahoes, etc. It is a bad feeling, and then you have to tow it somewhere or have it towed. Having it go out in a boat just compounds the problem.