Gas tank leak...
 

Gas tank leak...

Started by Geom, April 07, 2014, 04:26:11 PM

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Geom

Ok guys, have an issue with the gas tank. We drove our bus to its new temporary home. While en route everything appeared fine and I don't recall seeing any fuel leaking. After we got the bus to its new spot, a day later (when we stopped back by with supplies), I noticed a small wet spot outside, on the driver's side of the bus, just aft of the front tire. I quickly established the spot was diesel fuel. It's not a huge amount of fuel, so I wiped it off and (optimistically) tried to dismiss it as possibly some weird vapor issue. I placed a drain pan under the spot to capture any possible additional fuel. I left it last night and went back to check on it this afternoon. Well the leak is still there. So I took a flashlight and crawled around that side of the bus to see the source. I really can't figure out where it's leaking. It just seems to be emanating from driver's side of the lower tank. The tank runs the full width of the bus. As you know with fluids, where the fluid is dripping rarely has to do with where the leak actually is. The bus is leaning, somewhat, in the direction where the dripping is happening, as one would expect. I checked around the tank, with a flashlight, and underneath it. The tank looks pretty solid and I don't see any corrosion on the tank itself. I poked at it fairly well around where the fluid is and nothing appeared corroded on the tank. The only wetness is localized to that spot. The tank is completely dry everywhere else. There are support struts, that the tank sits on (about 6 I think), and each seem to enclose a metal strap around the tank and affix it to the bus. What I did notice was that one of the struts (on the same side where the leak appears to be) appears fairly corroded. The others appear to exhibit a normal amount of wear, but this one looks fairly corroded. I can't see around the strut itself or really under the bus, so I don't know if that has anything to do with it. The tank looks like it just sits on these struts, but the struts are not a physical part of the tank.
I took a few crappy pictures to see if they could be useful.

They're mostly looking up from the bottom of the bus up towards the bottom of that strut. You can see the corrosion crack in those. One interesting photo is a profile picture from under the bus, next to the strut.
You may notice what looks like a hose/line tucked up inside the frame.

My questions I suppose are:

1) any suggestions on what to do next
2) is this something that can be relatively easily repaired
3) do you think the tank will require removal
4) will it require replacement
5) what is that hose/line tucked up next to the frame near that spot? Is it a fuel line? If so could that possibly be the culprit?
6) anyone want to venture a (reasonable) guess on what it might cost to repair
7) where would I have work like this done? Any recommendations for a place near Kansas City?

The leak is not particularly large, only a few occasional drips. But as you know, big things usually start out as relatively small things; and I'd like to deal with this before it becomes a big thing.

I'm pretty sure this is the original 165 gallon tank that came with the bus.

I've uploaded the pics that I managed to take this afternoon. My phone battery died right in the middle of taking pics, of course :). But I plan on going back out there Thursday to reassess and snap more pics.

Here is a link to the photos: https://www.dropbox.com/sh/mqxs6whivn0s6gz/XQTGMjKnyS


Your help and advice on this, as always, is appreciated.
George
1966 GM 4107
6v92 Turbo
V730

Utahclaimjumper

 Don't neglect to inspect the TOP of the tank also, I've seen tanks that are leaking from the "pick-up" at the top at the gasket,  plumbing,  and so forth, it will run down one side (usually the side you can't see) and across the bottom to the low point.>>>Dan
Utclmjmpr  (rufcmpn)
EX 4106 (presently SOB)
Cedar City, Ut.
72 VW Baja towed

chessie4905

   I would suspect the leak is at the end where you see it and probably where the end of tank is welded to the sides. The rest of the tank is pretty well protected with the mounting straps, which have woven asbestos material between each strap and the tank. The straps are attached to individual crossmembers that are then bolted to bus bulkheads. Try cleaning the area really well and spraying talcum powder or equivalent  to the area to see where the leak originates.
GMC h8h 649#028 (4905)
Pennsylvania-central

luvrbus

It is probably the tank ends like Chessie referred to and any good radiator can repair it and coat the inside,it's not that hard to remove when empty  ::) GM's do rust   
Life is short drink the good wine first

Geom

Thanks for the info.
I found a shop here In town that can look at it. We'll see what they find.

One thing I thought about... whenever I open the gas tank, it makes a hissing sound as it equalizes with outside pressure (meaning there's a slight vacuum in the tank). I would suspect that if there really was a hole in the tank, that would not be happening. And equalizing the tank doesn't seem to affect the leak. So now I'm wondering if it's not a fuel line or similar that's leaking vs the tank itself. As noted above, when I took one of the pictures yesterday, I noticed what looked like a possible fuel line running through the frame on the drifer's side. Anyway, we'll see what the folks at the shop have to say.
Thanks again.

1966 GM 4107
6v92 Turbo
V730

Geom

Just a quick update:

Well I ended up at a different shop. The first one, I took it to, felt uncomfortable working on the coach; as they didn't have experience with this type of vehicle/tank. They recommended a coach specific shop here in town, Master's Transportation (they work mostly on school buses and fleet coaches). They've had it about 3 days now. I talked with them this morning and they're still working on removing the tank to inspect it. They say they have it mostly apart, but the gen intake is in the middle of the tank and is making it challenging.

Anyway, hopefully they'll be able to get it out today and inspect it.
He's not sure if the tank will be fixable, "depending on where the leak is".
I'm really hoping to avoid putting a new tank in it (not even sure where you'd get one!), as the current tank looks just fine to me!
So we'll see...
1966 GM 4107
6v92 Turbo
V730

Geom

Well I got my response back from the shop finally today.
After a week of "we're not sure how to remove this tank", "there are a bunch of lines there we need to remove", etc, etc, etc, they finally decided to get it up in the air and look at it from underneath. After which they said it would be $4000 to replace the tank, as they did not think it was fixable! Yup you read that right, $4K to fix a gas tank! After I picked my jaw up off of the floor, I told him to put it back the way he found it and I'll come pick it up this afternoon.

Anyway, what little info I could get from the guy is that there is some corrosion, under one of the straps, on the tank. That's where they believe the leak is coming from. Most of that money is in labor, as he says the tank itself is only $300 (which shocked me that it was that low). He also thought they might have to fashion a couple of new straps as they did not know where to get additional ones. 

The floor on this bus was lowered to make more headroom inside. While a fantastic thing on the inside, it apparently complicates the removal; as the floor apparently is directly over the tank and lines. He said they'd have to remove the tank out the bottom, vs the side. I kind of expected they'd have to remove it from the bottom anyway, so I'm not sure why that's so surprising to him, but anyway, he listed that as a reason for the labor.

Anyway, the leak is very minor and it had actually stopped leaking (more likely just not leaking enough to drip/pool) so I'm certainly not going to worry about it now and I definitely don't want to fork over $4k for a gas tank.

What are your thoughts? Is this guy crazy or is that a reasonable amount to expect for this?
I figured removing the tank would be required to fixing it, regardless, but he seemed intent on making a price distinction between a repair and a replacement.

I just don't think these guys really knew how to pull that tank and I don't think that they really wanted to do it anyway.

Are there any temporary fixes I can apply in the meantime? I'm not sure I can get to the leaking spot with anything like JB Weld or similar, but would that even hold?

I realize that I'll most likely eventually need to get that replaced, if for no other reason than peace of mind. Any suggestions on where would be a good place to get it done?
Since we plan on living in the bus, we can be fairly mobile and plan a long distance trip with this repair en route.

Your suggestions and ideas are greatly appreciated as always.
1966 GM 4107
6v92 Turbo
V730

Dave5Cs

George I think they priced it high because they either didn't know how or didn't want the job. Some think just because we have a coach that we are made of money. If it were me I would make some Run up blocks and get it up on them and block the jack points so you can get under it and see whats going on. Is it fixable, is there a line going to a generator that might be leaking. Have someone look under at the area while you take a rage and an air hose with about 8PSI or less and put some air in there and seal with the rage at the fuel door openng. See if it picks up and where. Might give you a better ideas what going on. Fuel hoses get old and crack but the motor might run rough or stop after awhile. Not so much if it is the tank.

Dave5Cs
"Perfect Frequency"1979 MCI MC5Cs 6V-71,644MT Allison.
2001 Jeep Cherokee Sport 60th Anniversary edition.
1998 Jeep TJ ,(Gone)
Somewhere in the USA fulltiming.

Len Silva

$4K is just their way of saying they don't want the job.
Can you open up the floor above the tank?  That would make everything much easier.

I also question the sound when you open the cap.  Shouldn't this tank be vented.  I don't know, my experience is with much older buses.

Hand Made Gifts

Ignorance is only bliss to the ignorant.

luvrbus

Red /Coate was the way to go for old tank leaks but the Bio in diesel now causes it to turn lose. The tank was installed it should come out. 4 grand does sound a little steep and I doubt you can buy a new tank for that bus for 300 bucks, they do rust around the straps and leak if not repaired it will get worse where ever the leak is

good luck
Life is short drink the good wine first

chessie4905

   Tank is relatively easy to remove. First. cut the damn generator line and relocate if afterward to the filler end, if necessary. There are mounting bolts that attach the tank crossmembers to the body. 10 or 12  3/8x1 1/4 uss bolts attach crossmembers to bulkhead flanges, if I remember. Don't remove nuts from the long threaded studs right now. You have to access the fuel filler neck through an access panel in the interior floor above the neck to remove it; 6 bolts, I believe, and disconnect fuel sending unit wire. The tank slides out the drivers side with the a/c panel raised. You will need to remove air drier if it has one in the way and remove copper air brake supply line loop at it's connections at top of tank area at that end as necessary. Tanks are heavily tin plated so area under straps is usually in good condition. Tank must be empty when removed to avoid tank or body damage. Don't let end drop when it clears body. If it is necessary to remove straps with tank out, thoroughly clean threads on strap fasteners 3/8x24 sae. You don't want to snap any off! If any of the crossmember bolts broke off while removing, now is the time to drill out and chase all threads with a tap and die. Couple of things about re-installing tank: Tighten straps evenly to keep tank perpendicular to cross braces, use antiseize on all threads, and use a long straight edge to make sure that cross braces are evenly lined up with tank centered . Also make sure to do some measuring to make sure crossmember holes line up with body holes. Once tank is back in, you can loosen a strap some to tweak to line up hole if off a little. Oh, and grease the flange that the crossmembers have to slide on in re-installation to make it easier. I didn't line up my braces before installation and had difficulty. (changed to larger tank). Otherwise, it wen't fine. Clean and paint braces and straps before installation. Some radiator shops can solder/repair the tank if necessary, depends where you live.
   Those prices are insane; call Luke if you are near. He is obviously not interested. Experienced should not charge more than 500 bucks r and r plus whatever tank needs.
   Those tanks WILL rust if the coach sits near an Eagle too long. Other than the ends, most of the rest of the tank is pretty well protected from the elements.
GMC h8h 649#028 (4905)
Pennsylvania-central

luvrbus

Lol the one place a Eagle will not rust are the 2 tanks
Life is short drink the good wine first

Geom

Thanks for the info! Will try to follow what of it I can. This will be useful in figuring out what my next steps are.

That's pretty much what I figured when I heard the price. They really didn't want to work on it. I think the guy let slip pretty much exactly that. He told me after I told him to put it back together I was coming to pick it up, his tech wiped his forehead and said whew! LOL!
Anyway, I just need to find a reliable mechanic/shop whose opinion I can trust and who knows these babies well :D

I'll almost certainly need to take this somewhere to be worked on. I don't have access to facilities that can remove the tank. Knowing what I'm looking at, however, and why it's being worked on, will be quite useful  ;D

Chessie, where is Luke based out of? I'm in the Kansas City area but I'm willing to travel (some) and make a trip out of getting this done. His name has come up before with many a compliment :D

Clifford, that's what I was worried about. That diesel will eat through any temporary fix and probably just make an ever bigger mess, lol. Oh well...
I was surprised by the tank price as well, maybe I should have him order it anyway :D
How easy are the straps to come by, if they needed to be replaced?

Dave, I like the idea of pressurizing the tank with air. I think that will definitely help in finding it.

It seems to have slowed down enough for now for it not to drip, at least. The tank is about half full, which I think might indicate where the leak is. Hopefully...

I do want to get this dealt with, but will probably wait it out till I find the right shop along the way somewhere, we'll see... :)

Thanks again for the help,
George

1966 GM 4107
6v92 Turbo
V730

B_K

Try giving Sam Caylor a call.

Caylor Supply LLC
www.caylorsupply.com/‎
Caylor Supply, LLC specializes in maintaining & repairing MCI motor coaches.
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   4712 Rock Creek Rd, Rantoul, KS 66079
(785) 878-3405
Bus Parts
Got a bus you would like to get rid off? Give Sam a call.

;D  BK  ;D

chessie4905

   Luke is in New Jersey. Sounds like the leak is at the end of tank. If I didn't have to remove it, I'd thoroughly clean the suspected area and then spray the area with spray talcum powder or equiv. to locate the precise leak pont. Then I would drain the tank or mostly and drive coach on a slope to keep remaining fuel away from that side. I'd then wire brush the area with a drill with a wire wheel and then thoroughly clean with some lacquer thinner several times till fuel seepage is almost stopped and then mix up some JB weld and apply 1/2 inch beyond the thoroughly cleaned  affected area. Allow it to harden over night, level coach back up and add back some fuel to check it. If OK then, add rest of fuel, check it occasionally in next coupe of days. If ok, move on. If not, you missed the leak point...repeat. JB weld is awesome, however area needs to be thoroughly cleaned for good bonding.
GMC h8h 649#028 (4905)
Pennsylvania-central