Good News, Bad News, and a couple of questions

[ZTatZAU]

I've learned quite a lot in the last few weeks! There's been both "Good News" and "Bad News" along the way and, of course, I do have a few questions for you Buick guys...

Bad News: Not necessarily Buick related here; but the transmission in my 2002 Blazer started going into "Limp Home Mode" intermittently a few weeks ago.

Good News: In addition to eventually solving the Blazer's limp mode problem, was that the loss of our daily driver was just the kick in the a$$ I needed to get the 75 LeSabre back on the road again.

Bad News: In order to get the Buick roadworthy, I had to install a new master cylinder which had been leaking fluid down the front face of the lower half of the vacuum brake booster on the firewall.

Good News: The master cylinder replacement and brake bleeding went well with no apparent damage done to the booster unit nor did any of the brake fluid find its way into the passenger compartment!

Bad News: While the gas gauge hasn't worked in the 19 years I've owned this Buick, despite having just put several gallons of gas in the tank, the car wouldn't start until I replaced the fuel pump and spent a good bit of time priming by hand at the carb.

Good News: The new fuel pump seemed to do the trick and the Buick got us to and fro until the Blazer's transmission problem was solved.

Bad News: Then just the other day, while going down the road nicely with what I thought was plenty of gas in the tank, the engine died and would not restart. After getting the car home and putting a few gallons in the tank just to be sure we hadn't run out of gas, it still wouldn't start and I resigned myself to the idea of replacing the recently replaced, but apparently defective fuel pump. It was then that I got down and had a look under the car and saw the steady stream of gas leaking from the front right corner of the gas tank. ARGHH!

Good News: I've dealt with leaking tanks before, and while there's hardly a speck of rust on the Buick, I felt confident that a bit of aviation fuel tank sealer applied on the outside of the tank while still in place would make short work of any small pinhole(s) that I might find.

Bad News: After adding a bit more gas to help locate the leak(s) and getting the car up in the air, it became apparent that this was no pinhole as gas was now flowing from the entire length of the horizontal seam across the front of the tank and finding its way at first to one corner and then to both front corners of the tank and onto the floor...

...When the leaking finally stopped I stuck a hose, with my thumb over the exposed end, down the filler neck to verify the tank was empty and reluctantly accepted the fact that the tank had to come out of the car to be properly sealed up or replaced. Double ARGHHs!

Good News: In addition to the tank mounting straps and hardware being in almost like new condition on this car, I now have my own lift in the shop which in the past, I'd only dreamed of having while removing gas tanks from old cars on jack stands and lying on the ground. This was going to be a snap! In addition, for the first time, I had correctly identified the sending unit's ground wire and its attach point on the underbody forward of the tank and the wire going to the gas gauge coming out the rear of the tank and which disappeared through a grommet into the trunk where a quick disconnect was located. Hey, I thought, by the time I'm done I may even get my gas gauge working again! And while everything was coming apart easily with no snags, and with a plastic garbage can sitting atop a rolling cart ready to receive the tank... for some reason, I decided to wait till this morning when I could enlist a little help before completely removing the two straps and lowering the tank.

Bad News: Early this morning then, with my helper holding up one side of the tank and me with one hand under my side and with the other hand I unscrewed the last few threads of the strap attach bolt on his side. I heard quite a grunt as his side of the tank came down smartly a few inches and I asked him if it seemed heavy? To which replied only, "Yeah! Pretty heavy! It wasn't until I removed the second bolt and took the weight of my side with my free hand that I realized "How heavy!" What a disaster this would have been had I tried completing the job the night before by myself! It turns out, after kicking the rolling cart and trash can out of our way, and wrestling the tank down and onto the ground, I siphoned 16 gallons of fuel out of a tank I thought was empty. At 6 pounds per gallon plus the weight of the tank itself, neither one of us was ready for; or at all prepared for the 150 pounds or so of the not-so-empty gas tank. After apologizing to my friend for my mistaken notion about the tank being empty, my thoughts immediately went to Bernie's remarks in reply to another of my recent threads in which he warned about the perils that often follow those two famous words... "I thought...!"

Good News: Once the tank was fully out and a full and proper inspection was performed, all the symptoms made perfect sense and the faults became perfectly clear.

Regardless of the amount of fuel in the tank, the fuel pump could not reliably supply fuel to the carb because the pump was sucking air, instead of fuel, as a result of the increasing deterioration of the rubber fuel feed line near the spring clamp where it attaches to the tank unit's steel fuel line. Visible cracks in the dried out portion of the rubber hose were now apparent and definitely leaked air where when an air hose and a thumb were applied to opposite ends of the hose.

As for the leaks in a tank with no visible signs of rust and with 95% of the factory undercoating finish still intact? Well, There was no leak! The source of the leaking fuel was a similarly deteriorated rubber fuel return line very close to where it attaches to the steel return line in the tank. When the engine was running, excess fuel, instead of going back in the tank, was being pumped overboard all across the top of the tank and then flowing down the path of least resistance to the seam flange and spilling off at the corners.

So Bernie, "You were so right!" We should all be careful whenever saying or thinking, "I thought..." At first I thought I was out of gas! Then I thought I had a bad fuel pump! I next thought I had a leaky fuel tank and then thought I had a seriously leaking fuel tank seam! Lastly, when preparing to drop the tank, I thought I'd convinced myself that the tank was empty! In fact, none of the above was true!

The best news is really all the good lessons that I've learned through this entire ordeal; and of course that 24" of new rubber hose will have me on the road again. I also discovered that, except for what appears to be a loose connection at the little rubber cap where the fuel gauge wire attaches to the top of the tank unit, my fuel level sending unit inside the tank is operating correctly with decreasing resistance from the ground wire to the gage wire connector as the 16 gallons of fuel was being siphoned out of the tank.

And then there's this... found taped to the underbody... above the tank after it was removed...

Apparently some sort of production line build sheet giving all the particulars about my Buick when it was being built! This will go very well with the original dealer window price sticker that came with the paperwork when I bought the car! I am happy to have found this build sheet and that it's still in such great shape after being taped under the car for the last forty years!

I do apologize for my excessive verbosity but I thought (Uh-Oh, there I go again) that some here may enjoy hearing about this adventure or even benefit from all the things that I thought and then subsequently discovered were not as I thought!

As for my questions...

1) What's going on with the fuel filler neck inside this tank (baffle-wise?) such that I could insert a rubber hose down far enough to appear to have reached the bottom of the tank and then being withdrawn with a thumb over the end of the hose without a trace of fuel inside or on the outside of the hose when in fact the tank was over half full? I'm still very puzzled about that???

2) The little black cap where the fuel gauge wire attaches to the top of the tank sending unit? (See photo below)

At first when testing the resistance from the gauge wire connector to the tank ground wire, I was showing an open circuit. Then after a little gentle prying and twisting of the cap my multimeter showed a steadily decreasing resistance (100+ ohms down to about 30 ohms) as the 16 gallons of fuel was being drained.

Is this little black cap a connector of some sort? Or perhaps Is the cap an insulator that can be removed to repair a bad connection there? Any help on this will be appreciated as it seems to be the key to getting my in dash fuel gauge working again!

ZT

Sent from my iPad

[smithbrother]

A lot of those black pieces are push on, pull off electric connectors. They are insulated to prevent a chance of a spark, NOT good around gas.

Dale in indy

[buick5563]

Best post in a while. Good job ZT!

[ZTatZAU]

Thanks Dale! I was hoping that was the case but I'm a little hesitant to tug on any harder than I've already tried until I know for sure. Hoping someone else will confirm your hunch. Trouble is my Buick is to young for most of you guys to have fooled around with.

I should mention to you that Whizzers and Cushmans were how I got around the neighborhood before moving up to some pretty cool Limey bikes and a '55 Merc 2 door sedan project by the time I had a drivers license. One of these days I'm going to have to make a list of all my past rides. There's a lot of them that I sure wish I still had that would bring a pretty penny these days. The trouble is, I always had to sell what I had to afford what I wanted next! Like the '69 Corvette 350-350 roadster that I sold in '77 for 3 grand to put toward the lot where I built the house we still live in.

ZT

Thanks a lot to you too Mike. I'm just a newbie here and wasn't sure how my "story line" would be viewed or accepted by you guys. It's nice to know that you enjoyed it!

ZT

[60FlatTop]

Well, what do you think of that.

Bernie

[ZTatZAU]

Well, what do you think of that.

Bernie

Did I not make my thoughts clear enough for you Bernie? <LOL> What did you think of that?

And can you, or anyone else, provide any info on that little black "cap/plug/insulator/connector" on top of the tank sending unit? Does it simply push on and pull off as Dale opined? Or is it a hard wired connection down through to the float rheostat?

ZT

[ZTatZAU]

Well... Dale nailed it on the little black cap on top of the sending unit. It is indeed a removeable connector! I got a little more aggressive with it just a few minutes ago and it pulled right off. A little clean up of the contact sleeve and pin and my gas gauge should be back in service!

ZT

[JohnD1956]

Check on that sending unit again.  I'm pretty sure it should read 0 ohms when empty.  My 72 had the canister style sending unit.  The float rides on the pickup tube and was getting stuck.  Many times it would take several hours for it to go back to the top when the tank was filled.  On my two long trips it was not uncommon for me to need gas again before it would even move.  It appears the float was swelling up and I guess it was from ethanol gas.  I tried to sand it with some 400 grit sandpaper but then it began to tilt on the pickup tube and got stuck again.  I gave up before making it too loose and still it had to be shook hard to get it to drop to the bottom of the scale.

 

I did replace it with an aftermarket pickup, but without the canister design, the float is subject to minute fluctuations in gas level. Go around the corner and the gauge flips around. Kinda sucks, one way or the other, but the canister was the baffle for the float, and the new unit is more conventional in design.  At least I can get a feel for how much gas I have. 

 

As to your question about dropping the hose in the filler neck for a level, it may be that a previous owner installed a anti theft device. It was not uncommon to do so after the 1973 oil embargo and the skyrocketing gas prices that followed. I heard, but have no proof, that some manufacturers even installed some such devices  from the factory.  But your tank is probably a lot like mine, and the rear baffle is pretty close to the filler neck, possibly blocking the hose from making the turn to drop into the gas below the pickup.

[NTX5467]

ZT, you have perfectly illustrated that "simple things" should be investigated FIRST rather than heading toward the "worst case scenario" first.  Only thing is that you had to get the tank lowered to reallly find the problem, although it was not what you suspected.

 

This is ALSO a perfect example of how ethanol-blend fuel degrades rubber hoses!  It dries them out from the inside out, leaving behind a rubber that is porous.  When it gets past the inner fabric web reinforcement, then the outer level can flake off!  Those fuel lines, back there, are "out of sight, out of mind", although the gas line at the front of the metal fuel line in the engien compartment can be "in sight".

 

In spite of all of the "ups and downs" of your adventure, I know it'll be great to know that everything "back there" is in fine condition . . . which can be worth the efforts it took to "get there".

 

Thanks for the great story!

 

NTX5467

[ZTatZAU]

JohnD & NXT, I appreciate your thoughtful replies!

I did in fact have another look at my sender and, like you John, I've ordered an aftermarket replacement. (A Spectra Premium FG110B from Amazon - $53 and change with free 2nd day shipping while my Prime 30 day free trial is still in effect). Turns out my sending unit was pretty narly looking and the bad connection wasn't at the push on connector on the outside of the tank as I'd thought but rather on the underside of the sending unit cap where the insulation on the flat ribbon conductor had delaminated and broken completely off the underside of the connector pin.

The replacement unit is almost identical to the OEM sender in my '75 LeSabre; the only difference being a slightly different vapor collection setup near the top of the sender. And while the outside of my tank didn't look that much different than when it left the factory, I also spent a good bit of time, last night and today, flushing and cleaning out the inside of the tank.

And while I didn't find an aftermarket anti-siphon device, as you suggested, I discovered it was indeed the tank's internal baffling that kept my test hose from reaching down far enough to reach the half load of fuel that was in the tank! My learning continues!

And NXT, don't get me started on the mandated BS ethanol farce which BTW is a perfect example of the crony capitalism that's doing as much damage to our way of life as the other camp's entitlement mentality! That's, "Nuff said!", on that topic lest I'm warned for getting a tad too political here! I will say that the whole ethanol debacle is the bane of many of us in the piston powered low compression general aviation community where non-ethanol "mogas" is by far a superior fuel, in all respects, than the 100LL (Low Lead) AvGas used in most certificated light planes today. The only trouble is finding "mogas" that doesn't have the ethanol in it.

You are correct too NXT, in that even though I came the long way around, I will indeed be feeling pretty good about "everything back there" and I do intend to replace all the rubber hoses "up front" too! I have heard that the current production rubber fuel hose material, if it's marked with an SAE specification as opposed to the cheapo Walmart stuff, stands up way better to ethanol in the fuel than the original rubber hoses in our old cars. I was also pleased to note that the new sending unit I purchased is tested by the manufacturer to stand up ethanol laden gasoline. So I should be good to go for a good long while; once it's all back together.

And I do appreciate you letting me know that you enjoyed "My story!"

Thanks again to you both for your replies! ZT

Sent from my iPad

[NTX5467]

Thanks for the updates and pictures!

 

Rubber hoses built since 1992 are the better stuff, regarding ethanol resistance.  In the past few years, though, a better hose has become available, but from what I understand, it does not look correct when compared to the normal fuel line hose.

 

One other thing which has surfaced in these AACA forums regards fuel pumps and their neoprene-blend rubber diaphrams.  Although the material can be "the best" for ethanol resistance, IF the diaphrams are allowed to dry out in storage, THEN the rubber can become brittle and later fail.  So checking the "weep" hole on the pump body can now be important for vehicles which see limited use or are put away during several months of the year (and are not started or run).

 

Used to be that when somebody did a "barn find" vehicle, they'd install fresh fuel, possibly change the oil and coolant,add new tires, and they were "good to go".  Now, replacing all of the rubber fuel system parts should be added to the list . . . including the ones not in ready visibility.  Those things might last a while before failing, but if you're going to be bragging about it, these things need to be taken care of sooner than later.

 

Thanks again,

NTX5467

[ZTatZAU]

Thanks for the updates and the pictures!

...IF the diaphrams are allowed to dry out in storage, THEN the rubber can become brittle and later fail...

 

Thanks again,

NTX5467

To tell you the truth NXT, I think this is what probably had more to do with the deterioration of my rubber hoses than ethanol laden gas. The car has been sitting in storage, and not driven, for the better portion of the last fifteen years. So it really hasn't seen much in the way of ethanol until only quite recently. It's the drying out, over time, with no fuel of any kind in them that I think "did them in!"

ZT