Do in-tank fuel pumps give any warning of impending failure/

As far as PCM or BCM failure is concerned: Don't Ford's late model system designs provide a "limp home" feature as regards to (most) control module failures?

I've had brake cylinder and master cylinder failures in the past and none have left me completely dead in the water. I do carry along a can of brake fluid.

We just had our first ever dead RV chassis battery occurance during an excursion in Oregon. The V10 would not even budge (I had left the headlights on). I merely pushed the battery boost solenoid rocker switch on the dash and the engine fired right up. In case the coach battteries would have also been too dead to do the boost, I also have onboard two other independent systems that would have made possible eventual starting of the main engine.

FWIW, in case something does leave us dead in the water, I permanently mounted on our motorhome's roof a celllular band antenna feeding a 12 volt cellular band booster preamplifier inside that allows our cell phones to receive and transmit in dead zones where only one, and sometimes no, signal strength bar is showing on the phones.

"You just made my point and my day.

That's why I wish my E450 had both twin fuel pumps and twin alternators. If what you experienced had happened to you in, say ... Plush, OR or Dubinky Wells, UT ... you would be glad that you had an installed and operating backup pump or backup alternator in your rig so as to get you somewhere closer resembling civilization."

The fuel pump and alternator aren't the only things that may fail without warning leaving you stranded. What about the PCM or BCM? Or braking components such as the master cylinder? If any of these fail you could be stranded as well. Are you going to duplicate everything that, if it fails, would leave you stranded? I don't think you could.

Once yes on the Suburban I kept losing power, then I had power. The pump was shorting out. Then once no in the Tahoe, just went. Very expensive repair as you have to drop the fuel tank to get the pump. Once they saved my gas and put it back in. Another they took it and wouldnt do anything about a credit..

I would expect a twin pump module would be less than double the price.

And if there was a dash indicator.... maybe both don't need to run. Presser sensor could turn one off. Even alternate at each start up.

Of course if you carry a spare part... it will never actually fail.

BurbMan wrote:
jfkmk, I killed the battery cranking the engine, so the only thing left to do was push....

pnichols, it's still worth it to carry the belt even if you can't change it. If you get roadside assistance to a local garage they can change it quickly if they have the part...sometimes getting parts can be a couple-day delay.

My alternator quit on our recent trip to Navarre FL, and fortunately the local Advance Auto had one in stock. I figured since the serp belt needs to come off I may as well change it too. So I web order the belt and alternator on Mon afternoon, and go over to the store Tues morning to pick it up. They have the alternator, but no belt. Guy scratches his head and wonders why the website let me order one when there are none in stock.

No problem though, they have one in the Ft Walton Beach store and will have it sent over today. Wed morning I go back to the store, no belt. Apparently Ft. Walton Beach didn't have one either. Guy apologizes profusely and says they will have one sent over from Pensacola.

Thurs morning, back to the store, no belt. Not only no belt, but 4 guys behind the counter, and nobody knows anything about a belt coming from Pensacola. There is no record of anything that happened the last 2 days, I felt like I was in the twilight zone.

After I get a little curt with the kid helping me, he says, well wait a minute, what part # are you looking for? So I tell him, he pops over the to belt rack, grabs one, and says look, we have one in stock, why did the other guy say they were having one sent from Pensacola?

Cue twilight zone theme music....Since I installed the alternator on Tues afternoon, I wasn't keen on doing any more work while on vacation, so I wound up changing the belt when I got home....

You just made my point and my day.

That's why I wish my E450 had both twin fuel pumps and twin alternators. If what you experienced had happened to you in, say ... Plush, OR or Dubinky Wells, UT ... you would be glad that you had an installed and operating backup pump or backup alternator in your rig so as to get you somewhere closer resembling civilization.

By the way, I do not trust or believe that both new identical in-tank fuel pumps put into service at the same time would fail at anywhere near the same time. Modern engineering and workmanship - in all of it's glory - still can't come close to guaranteeing that (from my experiences with innumerous other products). Reading back in this very thread, I see electric in-tank fuel pumps failing all over the map time-wise. I'll bet if I had twin pumps, one could very well fail at 85,000 miles and the other fail at 195,000 miles. Yes ... you should replace both whenever either one failed, but the extra labor cost would be small, with most of the cost being the extra new pump ... but that would be a price some would be willing to pay so as to NEVER be let down with a failed fuel pump at the wrong time and place.

smkettner wrote:
Two pumps.... at what point do you replace both? Or do you always just replace the failed unit?

One pump.... I am thinking it might be less money and hassle to just replace the pump at about 10 years or 120,000 miles.

Assuming both pumps running as redundant units, so both have the same service life. They won't fail at exactly the same time, but they won't be far apart. So when one pump quits, you get a dash light that says you are running on only one pump. Now when you replace the pump, you'll have to replace two, since the other one is now due to fail, so to avoid double labor expense you change both pumps at the same time.

So you have increased mfg cost, doubled repair cost on the part since you now have to replace two instead of one, but prevented unexpected breakdowns.

jfkmk, I killed the battery cranking the engine, so the only thing left to do was push....

pnichols, it's still worth it to carry the belt even if you can't change it. If you get roadside assistance to a local garage they can change it quickly if they have the part...sometimes getting parts can be a couple-day delay.

My alternator quit on our recent trip to Navarre FL, and fortunately the local Advance Auto had one in stock. I figured since the serp belt needs to come off I may as well change it too. So I web order the belt and alternator on Mon afternoon, and go over to the store Tues morning to pick it up. They have the alternator, but no belt. Guy scratches his head and wonders why the website let me order one when there are none in stock.

No problem though, they have one in the Ft Walton Beach store and will have it sent over today. Wed morning I go back to the store, no belt. Apparently Ft. Walton Beach didn't have one either. Guy apologizes profusely and says they will have one sent over from Pensacola.

Thurs morning, back to the store, no belt. Not only no belt, but 4 guys behind the counter, and nobody knows anything about a belt coming from Pensacola. There is no record of anything that happened the last 2 days, I felt like I was in the twilight zone.

After I get a little curt with the kid helping me, he says, well wait a minute, what part # are you looking for? So I tell him, he pops over the to belt rack, grabs one, and says look, we have one in stock, why did the other guy say they were having one sent from Pensacola?

Cue twilight zone theme music....Since I installed the alternator on Tues afternoon, I wasn't keen on doing any more work while on vacation, so I wound up changing the belt when I got home....

Two pumps.... at what point do you replace both? Or do you always just replace the failed unit?

One pump.... I am thinking it might be less money and hassle to just replace the pump at about 10 years or 120,000 miles.

pnichols wrote:

jfkmk wrote:
At issue is you have two pumps working at the same time wearing out at the same rate. Your second pump might not fail at the same exact time but it would be close. You'd be better off cost wise replacing the pump at a given mileage interval.

Two wearing out "at the same time" is not going to happen. Take a quick study of the probability statistics concerned with the failure of electro-mechanical devices and it'll show you that: The probability of one electro-mechanical item failing - mulitplied times the probability of another identical electro-mechanical item failing while in service along with the other - equals the resultant probability one must live with of both "going bad at the same time". These two probabilities multiplied together make for a very, very, very small probability of paralleled in-tank fuel pumps ever failing at the same time and leaving one stranded in a busy intersection or out in the middle of nowhere. Of course along with parallel in-tank fuel pumps one should have some kind of indicator on the dash telling when the first one to fail has, indeed, failed -> hence you're now relying on only one of the two in-tank fuel pumps and bettter do something about it.

jfkmk wrote:
The newer serpentine belts will go 150k plus miles and require releasing the tension at one point. It took me less than 5 minutes to replace it on my SUV and that was from opening the hood to closing it.

This seems to NOT be the case for the V10 engine in the common Ford E350 and E450 cutaway van chassis under a lot of Class B/C motorhomes. The mechanic that last changed mine in our rig (per my request at 45K miles for preventative maintenace) needed a special tool to do it (I think it had something to do with holding back, and/or maybe completely removing, the tensioner pulley to install a new belt). Plus ... I looked quite some time under our motorhome's van nose hood on our E450 and it's packed in there. I could not get near it's serpentine belt without removing the radiator shroud and then probably having to lay on the ground underneath the engine to snake a new belt up and around all the bottom sides of the various pulleys. I wouldn't want to have to do this out in the desert somewhere. Nevertheless, I carry a new spare serpentine belt anyway, just is case I can figure out how to replace a broken one should I have no choice - since one is entirely dead in the water when a serpentine belt breaks. At least with the old multiple belt design if, say, the alternator belt broke ... I could keep on driving with no alternator ... since some motorhomes can go a long distance running off the engine battery in conjunction with the coach battery(ies) powering all the engine functions (like ours can using the emergency boost switch).

By the way, a fuel pump tank access port will not be of any help in getting to the fuel pump in a motorhome ... unless the motorhome builder installed an in-floor access port directly above the tank access port.

Right. I never said both pumps would fail at the same time. I know all about probability and how it applies to risk (in this case the risk of both pumps going at the same time) and know it's practically impossible. My point is, if there wa s a spared pump in the tank, and it was running all the time the vehicle was running just like the primary pump, it would reach its end of life expectancy at the same time as the first pump. They wouldn't fail at the same time, but would be ready to. Even in industries where a pump is critical enough to have a secondary pump, the secondary pump would not be running all the time the primary pump is, "just in case". It would be switched over if the primary pump fails.

In the case of a vehicle, I go back to it would cost the manufacturers a fortune to provide the option of a second fuel pump. The cost would have to be passed along to the buyer. Most drivers can't check the air in their tires, do you think a spare fuel pump would mean anything to them? Probably so few would opt for this that. The relatively few who would want to would say forget it, I'll just change the pump out at 100k miles and save money.

A serpentine belt is infinitely easier to change than the multi belt set up and the belt is far superior, at least in my experience. If you had to remove the radiator etc to get to ONE belt, could you imagine trying to get to 3 or 4? The beauty of the serpentine belt is it takes up far less depth than the multi belt setup did. I have one of those "special tools" for replacing the serpentine belts. It's basically a long flat wrench to get to the tensioner and costs next to nothing.

I fully understand that when a chassis is built bu one manufacturer and sold to another to have the body they can't put an access port for the fuel pump, I just thought it was pretty cool that GM had thought about it for the Grand Prix that Burbman spoke of.

jfkmk wrote:
At issue is you have two pumps working at the same time wearing out at the same rate. Your second pump might not fail at the same exact time but it would be close. You'd be better off cost wise replacing the pump at a given mileage interval.

Two wearing out "at the same time" is not going to happen. Take a quick study of the probability statistics concerned with the failure of electro-mechanical devices and it'll show you that: The probability of one electro-mechanical item failing - mulitplied times the probability of another identical electro-mechanical item failing while in service along with the other - equals the resultant probability one must live with of both "going bad at the same time". These two probabilities multiplied together make for a very, very, very small probability of paralleled in-tank fuel pumps ever failing at the same time and leaving one stranded in a busy intersection or out in the middle of nowhere. Of course along with parallel in-tank fuel pumps one should have some kind of indicator on the dash telling when the first one to fail has, indeed, failed -> hence you're now relying on only one of the two in-tank fuel pumps and bettter do something about it.

jfkmk wrote:
The newer serpentine belts will go 150k plus miles and require releasing the tension at one point. It took me less than 5 minutes to replace it on my SUV and that was from opening the hood to closing it.

This seems to NOT be the case for the V10 engine in the common Ford E350 and E450 cutaway van chassis under a lot of Class B/C motorhomes. The mechanic that last changed mine in our rig (per my request at 45K miles for preventative maintenace) needed a special tool to do it (I think it had something to do with holding back, and/or maybe completely removing, the tensioner pulley to install a new belt). Plus ... I looked quite some time under our motorhome's van nose hood on our E450 and it's packed in there. I could not get near it's serpentine belt without removing the radiator shroud and then probably having to lay on the ground underneath the engine to snake a new belt up and around all the bottom sides of the various pulleys. I wouldn't want to have to do this out in the desert somewhere. Nevertheless, I carry a new spare serpentine belt anyway, just is case I can figure out how to replace a broken one should I have no choice - since one is entirely dead in the water when a serpentine belt breaks. At least with the old multiple belt design if, say, the alternator belt broke ... I could keep on driving with no alternator ... since some motorhomes can go a long distance running off the engine battery in conjunction with the coach battery(ies) powering all the engine functions (like ours can using the emergency boost switch).

By the way, a fuel pump tank access port will not be of any help in getting to the fuel pump in a motorhome ... unless the motorhome builder installed an in-floor access port directly above the tank access port.