fuel sending unit removal

[wazzabie]

Ok so I have the gad tank out of the 78 K5. The fuel sending unit has 4 outlets. How do I remove the sending unit from the tank? Also how can I test and repair the sending unit. I don't want to spend $ for a new one. Also all the fuel hose looks like rot. Initally I tried to save it but then just cut it to make life easy.

 

[dremu]

Ok so I have the gad tank out of the 78 K5. The fuel sending unit has 4 outlets. How do I remove the sending unit from the tank? Also how can I test and repair the sending unit. I don't want to spend $ for a new one. Also all the fuel hose looks like rot. Initally I tried to save it but then just cut it to make life easy.

There's a ring around the sender. After soaking the ring area in penetrating oil, tap the tabs on the ring GENTLY -- a punch or brass drift would work well; alternately a large screwdriver ... just be sure not to chisel the tabs off. Remember I said GENTLY.

Anyway, the ring moves, I donno, 30* or so, and then pops off and the sender lifts out. The rings are cheap at the parts place (Motormite has them in "Help!") cuz they're the same for all GM's, IIRC.

Installation is the reverse of removal.

Now, testing ... ohm-meter. Test resistance from the stud for the sender (should be a pink wire on the outside of the tank) while you move the float. IIRC it's a range of about 0 to 90 ohms, 0 being empty and the high end reading full.

HTH.

-- A

 

[wazzabie]

I'm not sure where I should be hitting the metal with a brass punch.

I took this pic. I circled and indicated where I think I should be hitting it. I've given it several good hits but it is not moving even after cleaning and putting anti-lock fluid one it. I'm I hitting the right spots?

http://img220.imageshack.us/my.php?image=fuelsendvq3.jpg

Also is this a heavy emissions? The canister line is block right?

78 K5 350 Auto

 

[dremu]

I'm not sure where I should be hitting the metal with a brass punch.

I took this pic. I circled and indicated where I think I should be hitting it. I've given it several good hits but it is not moving even after cleaning and putting anti-lock fluid one it. I'm I hitting the right spots?

http://img220.imageshack.us/my.php?image=fuelsendvq3.jpg

Also is this a heavy emissions? The canister line is block right?

78 K5 350 Auto

I thought the four-tube ones were later model, like maybe yours has been swapped already. I could be wrong. In fact, looking at the LMC catalog, I am -- the four-tubes started around '77-78. No clue.

Anyway, a picture is indeed worth a thousand words. You want to put a screwdriver into thing you circled, in the upper right with two arrows, and bang it to the left, anticlockwise. The circled thing, no arrows, 'bout 10 o'clock, is used to put it back into place, banging it to the right, clockwise.

And yeah, that inner ring DOES move ... eventually.

I'm thinking real penetrating oil, like PB Blaster or its ilk, is called for. I don't know anti-lock fluid (assuming it's not for brakes )and I have found WD40 to be less useful than urine for such tasks.

-- A

 

[dyeager535]

One addition, it is sometimes easier to work one side, then the other, that ring will tend to "dig in" to the opposite side. Probably not necessary, but has been nice and easy for me.

In your picture, I'd not use those little tabs to drive it, instead the other "indent" that you circled, as long as you can get good purchase on it. I used to use the tabs, but as mentioned, if the lock ring doesn't want to move, those tabs tend to bend.

 

[wazzabie]

Thanks for the help. I'll try some other type of penetrating oil.

This is the first time that the tanks has been removed. The 4 outlet is original to the 78 k5. What is interesting is that one of the outlets has been plugged from the factory. The k5 does not have the charcoal canister and as such does not need the return line. The k5 came with heavy duty emissions.