daily driver help!

[moose]

I have lost the fuel pump on my daily driver. It is a 1998 GMC It seems that I have the antisiphon ball check in the tank. I cannot get a hose past this to drain the tank. I also cannot get the vent hose clamp to release at the tank to try that path. any link to how to remove the ball check? I have googled it but cannot find what I need. I know there are several goot techs here so HELP PLEASE!

Thanks

Tim

[unklian]

Had the same problem, trying to drain my tank.
Never did find a good way.

[enjenjo]

you can draw fuel through the pump with another pump. I have done that in the past to empty a tank.

[moose]

I actually got a suggestion from a buddy who stopped by tonight. Simple answer lift the bed and leave the tank in place. Four bolts and a cherry picker should get it up and out of the way to access the pump. Sounds easier than I am sure it will be but I will explore that option. Sure beats wrestling 25 gallons of gas out of the tank!

Tim

[tomslik]

I actually got a suggestion from a buddy who stopped by tonight. Simple answer lift the bed and leave the tank in place. Four bolts and a cherry picker should get it up and out of the way to access the pump. Sounds easier than I am sure it will be but I will explore that option. Sure beats wrestling 25 gallons of gas out of the tank!

Tim

unless it's a yukon.....


btw, there's 6 to 8 bolts...
i leave the rear 2 in but loose and just pick up the frt of the bed high enough to get in and change the f/p module out...

[wayne petty]

80 percent of the time... i can pump the tanks out by beating on the bottom with a rubber mallet...

with the fuel pump relay cover removed and somebody holding it closed..


the pumps are a pain when the tanks are totally full...

you might also want to know that the 98 tank sending units are held in with a big snap ring..   you have to lube the new Oring to get the sending unit to push down to seat it before you can get the snap ring in...

there might be another way...   unfastening the 5/8 or 3/4 filler neck vent hose at the tank...   stick in a length of 3/8 fuel line.... you should be able to start a siphon then..   usually by blowing some air into the filler neck after you plug the filler vent opening you created..

use a tiny amount of air.. you will probably spray fuel all over the place... if you get wild..

a pair of the crank up harbor freight transmission jacks really help.. a single one with the strap over the top of the tank so it does not slide works well.. with a few milk crates to balance the tank when the fuel runs to one and...    oh.. you can also siphon the fuel back into the tank.. just keep the cans slightly higher than the tank...

http://www.harborfreight.com/450-lb-capacity-transmission-jack-39178.html

i keep one with me all the time.. they come in so useful for dropping tanks..    dropping transmissions...

i have taken to picking up spare pans..   having the muffler shop weld some short legs to the bottom of the spare pan.. so they will slide into where the straps are attached.. this prevents the transmissions from sliding around..   also gives them nice short legs to walk them under cars..

in a shop a long time ago..  i took the spare pans..    cut the bottoms off leaving about an inch and a half  of the sides with the bottom.. punched holes that matched the trans jack saddle holes.. so i could bolt  the short pan to the jack.. then slip the new trans with a regular pan on the jack without  needing to adjust the jacks arms..... made it almost impossible for it to slide off...

[chopped]

Put two pumps in my 98 GMC, then trades it for a 86 Chevy wagon.

[wayne petty]

thats a good point.... repeated fuel pump failures...


as i understand...  the fuel pump that is inside the fuel pump module is the same as earlier models...  so with care... you can save a bunch of bucks...  by taking it out and taking the module apart to replace just the pump....

i have not tried this... the chevy pick up i had to drill the broken bolt out of the exhaust has a cobbled together fuel system...  where the previous owner has removed the pump from the module.. cut the strainer off the pump.. used a hose clamp to hook it to the end of the hose...  used tie wraps to fasten the sending unit to one of the rods...  cut the fuel lines and installed a used bosch pump outside the tank...  twisted the wires around the terminals.. stuffed that pumps power wire under a fuse in the relay box under the hood..


more than likely. the cause of the original fuel pump failure was the totally carboned up relay contacts.. this would have reduced the power to the fuel pump and caused it to have a short life...

it only takes a few minutes to remove the relay and gently pry the fuel pump relay from its shell... then using a small screw driver or an antique points file to burnish the contacts.. then a short blast of brake cleaner ... it will clean the silver contacts and the relay should work again for a long time supplying full power to the hard working pump...

fuel pump relays are usually cheep compared to the price of the pump modules... but nobody thinks of changing them....

most of the time the new fuel pump module comes with a new pig tail... take the time and install it ...   be sure to cut the old leads about an inch and a half from the connector.. and then use the full length of the new wires...  so the tank can drop farther without stressing the wires ..   it comes with quality crimps... use a tool that dents the crimp.. not just a pair of channel locks..



the fuel filter does not just filter the fuel that the engine uses.. it filters all the fuel the pump pushes through it..  again and again and again...

when the filter gets restricted.. the pump has to work harder.. this causes the motor to draw more amps...  this causes damage to the tiny commutator and the brushes ...

the fuel filter O rings for gm come in a package of 10.. fit other places in the fuel injection lines also...  delco part number 217-452.. not cheep.. 8 to 10 bucks for the pack of 10.. but made of the proper material...  they are a reddish color.. if somebody reaches into a plumbing Oring box to sell you some.. punch them..  tell them i sent them the message..   these are the proper size for the pressure side of the fuel injection lines.. the return lines use a smaller size oring.. i don't have that number handy..


this is kinda off thread... but i like to explain stuff .. saves a lot of hair pulling in the future...

[348tripower]

Wayne,
Any truth to the theory of running around 1/4 of a tank all the time is hard on the pump due to heat?
Don

[wayne petty]

yes... totally... i was going to explain it.. but my cat was trying to get my attention.. needing petting..

when the fuel is run below a quarter tank.. the pump strainer can become uncovered for short lengths of time...  this allows air to be pulled in..  this causes the pump to spin faster .. the ceramic bearings can run dry..  the brushes loose the flow of fuel past them as coolant..

it just shortens the life of the pump..


driving the car or truck till it runs on vapors is also a great way to shorten the pump life..  these are high pressure pumps..  much like a power steering pump... roller vane... or sliding vane.. without fuel the just scrape..

i have taken apart noisy pumps and found the sides of the pump cavity torn up from the dry running...

to continue .. there is a way to tell if the fuel pump is going bad... but its not cheep price of the test gear..

a digital storage scope and a low amp current probe...

400 bucks  to $8K for a DSO..

$130 to 300 for a low amp current probe...

a lot of mechanics who do drivability have these tools ... for looking at injector current patterns.. various sensor amp draws...


the ability to see if an electric pump is failing.. while is it spinning in the tank... in a few minutes..    PRICELESS!!!!

but if you clamp the low amp current probe around the power wire to the pump..   you can see the amp draw of the individual windings of the pump motor as it spins at 5,000 +rpm...  digital storage scopes record the wave form so you can spread it out to look at them..

if your pump is good... it will have a nice even pattern...

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

if you pump is failing..

~~~~^~~~~~^~~~~~^~~~~~^~~~~~^~~~~~^  


what i am describing is the actual amp draws of the armature as it spins.. remember only one set of windings is connected at any time.. so set 1, 2, 3 ,4 ,5, 6...  1 2 3 4 5 6...   depending on the pump winding count..

some has six... some have 8...  bigger pumps more than that..


with the low amp current probe and your digital volt meter.. you can also look at the amp draw..  in amps.. not a pattern.. worn pumps will take more current.. and it will show up ..

most amp clamps are rated for 400 amps..  they don't show amps below 10 properly... at least the ones i have run across.. AVR and VAT machines have ones that will .. but ... a low amp current probe max current is 40 amps..

this link explains it and has graphics... showing what i am talking about.. and how to do some of the tests.. and is probably the most important link i have ever posted...



http://www.aeswave.com/articles/productarticles/currentprobes.htm

[57larry]

great tech here.I love kitty cats too