TE630 Gas Tank Leak...Again!

[jester6i]

Had my gas tank replaced under warranty in the spring due to gas dripping from fuel pump seal onto the exhaust pipe. This happened while the bike was running and while not running. Now I am noticing that gas is weeping from same area again, only this time it seems to only happen after the bike is ridden. When I dry up the gas around the pump seal, it does not leak again until the next time I ride. The replacement tank I received from dealer had the fuel pump mount shaved down perfectly flat, so I doubt it is a bad seal. Wondering if the pump itself is somehow leaking.

Any thoughts?

 

[gregjune]

I had two gas tanks replaced under warranty for the same issue. After the 2nd replacement I found the problem. If you remove the hideous EVAP emissions canister from the right side you also need to replace the "check valve" for fuel tank vent line behind the radiator with a straight thru fitting. Otherwise the fuel tank pressurizes and causes the poorly designed fuel pump flange to leak. Haven't had a fuel pump leak since. You may get a slight dribble from tank vent line after heavy front braking with full tank, but minimal.

 

[630 driver]

I was just going to say my SMS 630 had the same leaking issue. I took it to the dealer and they wanted to put a new tank on and keep the bike for three weeks so I took it home and noticed the little bolt on the top left side of the tank. ( left side as sitting on the bike ) I looked in the manual and noticed it was supposed to be a vent line. I made my own vent and it has been great ever since.

 

[XLEnduroMan]

Like they said, get rid of that one way (pressure) valve on the vent hose.

 

[jester6i]

Thanks to all for your input. Makes complete sense. Problem was exacerbated when bike was in direct sunlight and anytime engine was really hot. When I removed the EVAP stuff, I did re-route the vent line down the front of the bike, however, I left the check valve in. I will remove it and hopefully it solves the problem. I was not looking forward to more dealer down time and I was suspicious of the need to replace the tank again. Thanks again. I will let you know if that does it.

 

[jester6i]

So I pulled the one-way valve as suggested. There was a loud puff of air venting so I thought I may be in luck. A hard off-road ride and leak is back at bottom of the gasket. After doing some research, there is a permetex aviation product that is made for sealing fuel fittings, etc. I have to believe my replacement tank is not also bad and am going to pull it, drain the fuel and lightly coat both sides of the rubber gasket with this stuff. Of course, when I pull the tank and pump if I see anything funny I will bring it back to the dealer for a third tank. What a PITA. This is the product I found while researching:

 

[jtemple]

Where is the check valve? I didn't think I had one, but I could be mistaken.

EDIT: I just checked mine. I have a straight line coming from the lower tank vent for sure. I recall some greenish thing that might be a check valve in the line from the upper vent; the one that drains any tank overflow. That shouldn't cause any problems, that upper line doesn't seal up when the tank is closed.

I have had my 630 for a good long time, in all kinds of weather. No tank leakage problems thus far.

 

[mekanik]

+ 1 for no issues, so far I have left in my check valve, something about going for a long ride to the top of the mountain and while resting you can hear the Italian mistress mooing gently nearby

 

[jester6i]

The valve I removed was from the line coming from the top of the tank. It was greenish-grey. There was definitely a release of air when I pulled it off the hose. I don't recall seeing a lower vent hose. I will have to look again. In any event, I am probably going to pull the tank tomorrow and seal the gasket.

 

[mekanik]

There isn't a lower vent hose, the lower hose is the filler neck drain that sometimes is teed into the vent hose when the check valve isn't used. Without the check valve the tank cannot build pressure.
It probably is a good idea to reseal the tank anyway once it starts to leak it will still seep even without the pressure.

 

[jtemple]

Why does a fuel injected bike need a tank that builds pressure? Doesn't the fuel pump handle that?

 

[630 driver]

I had the same fuel leak issue when I picked my bike up from the dealer. They were going to replace the tank but wanted my bike so they could take it apart before they would order the parts. They planned on keeping the bike for three weeks. I decided to look through the manual and noticed that in the top of the tank most bikes had a vent line and mine just had a screw in place. I got a bolt and drilled through it so I could put a hose on there. I did not buy fuel line yet instead I used a bunch of small weed eater gas line. I looped it up over the handle bars and then down and finally through the little hole on the frame behind the front tire. I have never had a problem and the only time fuel leaks out is when I first fill the tank and I do stoppies or wheelies a little gas gets in the line. Very rarely does any drip out, it mostly goes into the tube right at the tank and then runs back in when I take off. I believe if you look at the manual it says nothing about a pressurized tank. If you had a pressurized tank the gasket and fuel pump would bolt together to create a pressure seal instead of just making a surface seal. Good Luck

 

[mekanik]

Why does a fuel injected bike need a tank that builds pressure? Doesn't the fuel pump handle that?

The tank does'nt need to build pressure, it is an emission reason, they don't want the fuel vapors venting to atmosphere, it was designed to hold small amounts of pressure then vent to the charcoal canister then burned through the engine later.

 

[jtemple]

I had the same fuel leak issue when I picked my bike up from the dealer. They were going to replace the tank but wanted my bike so they could take it apart before they would order the parts. They planned on keeping the bike for three weeks. I decided to look through the manual and noticed that in the top of the tank most bikes had a vent line and mine just had a screw in place. I got a bolt and drilled through it so I could put a hose on there. I did not buy fuel line yet instead I used a bunch of small weed eater gas line. I looped it up over the handle bars and then down and finally through the little hole on the frame behind the front tire. I have never had a problem and the only time fuel leaks out is when I first fill the tank and I do stoppies or wheelies a little gas gets in the line. Very rarely does any drip out, it mostly goes into the tube right at the tank and then runs back in when I take off. I believe if you look at the manual it says nothing about a pressurized tank. If you had a pressurized tank the gasket and fuel pump would bolt together to create a pressure seal instead of just making a surface seal. Good Luck

Mine had two vent lines from the factory. The lower one went to the charcoal canister and the upper one just dumps on the ground.

 

[630 driver]

My bike did not come with the canister I am not sure all the differences in the bikes but mine came stock with the power up kit also. My bike was one of the bikes sent over for $6,200.00 and I guess there were other bikes that sold for around $9000.00 my dealer did not know a lot about the whole thing only that my bike had the emissions removed before it arrived and the power up installed . We can find no other real differences. The tank had a bolt in the vent hose at the top so like I said I modified it . I have not had a leak since and the bike sits in the sun while I am at work here in Texas with some days being 104 + degrees.

 

[jtemple]

Yep, mine has two vents and has sat through all sorts of weather, from sub zero to over 100. No leaks.

 

[Rebelgd]

Well, my son asked for help this week on his leaking fuel tank. The bike is just out of warrenty so i dont expect much dealer support. We had the emissions crap removed last year but i noticed today the green check valve is still on the vent line. Tomorrow we'll pull the tank and reseal the gasket with some fuel safe sealant...plus 86 the check valve. Hope that does the trick.

 

[jester6i]

After filling the tank, letting the bike sit for 2 days, and then a few hard rides, it appears that my reseal of the gasket using the permetex goop worked! Bone dry underneath. Removal of the one-way valve was the key, I think. In its place, I routed a length of clear fuel line up and into my handlebar stem - just like the good ole days! During the re-install, I noticed that as I tightened down the silver plate over the pump and gasket, that there was a point when a gap appeared at the bottom, between the lower 2 bolts. At that point I had 2 choices - loosen the whole plate or keep cranking the bolts tight. I chose the latter because the fuel pump is pretty long and hefty in its own right and I did not want it breaking the seal on a hard bump, etc. Once I tightened the plate further, the gap disappeared. I do not recall if there were torque values listed in the shop manual for this or not, but you may want to check. Good Luck!

 

[630 driver]

After filling the tank, letting the bike sit for 2 days, and then a few hard rides, it appears that my reseal of the gasket using the permetex goop worked! Bone dry underneath. Removal of the one-way valve was the key, I think. In its place, I routed a length of clear fuel line up and into my handlebar stem - just like the good ole days! During the re-install, I noticed that as I tightened down the silver plate over the pump and gasket, that there was a point when a gap appeared at the bottom, between the lower 2 bolts. At that point I had 2 choices - loosen the whole plate or keep cranking the bolts tight. I chose the latter because the fuel pump is pretty long and hefty in its own right and I did not want it breaking the seal on a hard bump, etc. Once I tightened the plate further, the gap disappeared. I do not recall if there were torque values listed in the shop manual for this or not, but you may want to check. Good Luck!

Don't forget that the reason they stopped routing the fuel breather into the headset was because the fuel would eat the grease out and your headset bearings would rust and eventually become super loose. I routed my tube up and over the way to the ground just to be sure any vapors or overflows would not end up on the bike

 

[jtemple]

The 630 steering tube is a solid piece. It isn't slotted for the steering lock like the smaller TEs. The only place for vented fuel to go if you routed it that way would be onto the front fender. It wouldn't touch the bearings.

Not really a concern, as routing the vents that way would result in a kinked up set of hoses, considering the vent locations.

My vents dump right into my skid plate.