The Good, the Bad the Webasto ....

[Ray Davis]

Ken Zittrer (Bluevost) and I spent about 5 hours today trying to solve a Webasto problem that has us both stumped. I'm looking for help from the collective brain trust!

A couple of weeks ago I noticed a diesel leak back near the right side of the engine compartment. I put a drip pan under the bus as I didn't have time to deal with it. Yesterday when I went to the bus, there had to be at least a quart, perhaps a half gallon of diesel in the pan. OK, it's time to do something.

It's defininately the Webasto which is leaking, but Ken and I tried everything we could think of, but it's still leaking. Here's the pertinent (and perhaps not so pertinent) details, which will helpfully lead us in the right direction.

1. fuel leak seems to be in the incoming fuel line.
2. fuel comes in through a fuel filter (which doesn't appear to have any "filter element" inside).
3. It connects into the port labled "S".
4. There is another port labled "R", which has a fuel line, which exits out the side of the unit and heads into the engine area. Not sure where. This line doesn't appear to be leaking, although it was wet.

5. We replaced the incoming fuel line (from fuel filter forward), and also replaced the hose clamp. Still no luck.

6. It was noticed that when we opened the unit, that the square grommit which it used around the fuel inlets was crushed in some previous repair attempt (previous owner).

7. We did our best to fix up the crushed gromit, adjusted the electrodes, and replaced unit.

8. Unit still leaks at an alarming rate (5-10 drips per minute, worse when unit is fired up).

9. When unit fires up, it runs, but blows a LOT of white smoke, but otherwise seems fully functional.

We're hoping something above will be a clue to someone. The fuel line was 1/4 inch standard fuel line. We have no clue where the other line goes to/from. It's not clear whether it's another fuel in, or not?

We spent nearly 5 hours on this, having the unit apart 4 times. Everything is tightened as best we could, but almost immediately after buttoning up, it's dripping. If we fire it up, it starts dripping profusely.

Any suggestions would be most appreciated.

Thanks,
Ray

[Jon Wehrenberg]

I believe S is the supply, and R is the return. Fuel not used by the Webasto returns to the fuel tank.

Is there any way to photo the specific area where it is leaking?

Also, has the unit been cleaned 100% so the origin of the leak, not where first visible to you now, is evident.

If you need to, disconnect the fuel supply and return lines and plug them while you do what is necessary to make sure there is zero fuel, dirt, wet areas etc. Tracing a leak is impossible unless you can verify the source which may be some distance away from where you think it is.

[garyde]

Hi Ray. I would disconnect both lines and cap with a screw or bolt. If leak has stopped, reconnect one line and check again, if no leak , connect the other line. If it begins to leak, that line is leaking or your port is damaged.

[Ray Davis]

We are sure it's the supply line that is leaking. What's not clear is whether or not it's leaking from the hose itself (getting by the clamp), or it's somehow leaking further up the inlet nipple, and dripping back down onto the hose.

We can't tell that when the burner unit is removed from the combustion chamber. There was evidence of some fuel inside the burner unit, down where the S and R lines enter.

Once cleaned, and simply "sitting", it drips slowly. It's after the unit is turned on that it really begins to go.

Visually it looks like fuel is just getting around the hose clamp on the S side. But, we've cranked that down like crazy, replaced the hose and clamp. I'm wondering if that inlet has perhaps been damaged, and won't allow a seal?

Ray

PS: is the ton of white smoke somehow related to this problem? Does that indicate too much fuel?

[JIM CHALOUPKA]

We are sure it's the supply line that is leaking. What's not clear is whether or not it's leaking from the hose itself (getting by the clamp), or it's somehow leaking further up the inlet nipple, and dripping back down onto the hose.

We can't tell that when the burner unit is removed from the combustion chamber. There was evidence of some fuel inside the burner unit, down where the S and R lines enter.

Once cleaned, and simply "sitting", it drips slowly. It's after the unit is turned on that it really begins to go.

Visually it looks like fuel is just getting around the hose clamp on the S side. But, we've cranked that down like crazy, replaced the hose and clamp. I'm wondering if that inlet has perhaps been damaged, and won't allow a seal?

Ray

PS: is the ton of white smoke somehow related to this problem? Does that indicate too much fuel?

Ray, you indicate that it continues to leak in the same area, even after using a new hose clamp and hose. That indicates to me that it might be the fitting at that connection! Cracked, or loose in the pump.

IMHO clamps and hose are mickey mouse (no offense to Walt & Co.)when dealing with diesel. Have some Parker lines made up at your favorite auto store (NAPA) and install the appropriate fitting at the pump and fuel source!
It is also possible that the pump housing has a crack or defective casting (pinhole), that sprays onto the hose and makes you think the hose is the problem. I find that a good tool to trace diesel leaks is white Kleenex. The most minute amount of fuel shows up. Work from one end to the other using fresh as needed until you locate the leak. Wear the blue Nitrile gloves to keep the diesel off your skin (toxic and it burns ) when performing these tasks where repeated soakings are inevitable.

Hope this helps JIM

[JIM CHALOUPKA]

Ray, I think the white smoke is due to a clogged/dirty nozzle. It could also be due to excess fuel in the combustion chamber. If the smoke situation does not go away after several minutes of running, replace the nozzle and test.

[Larry W]

I had a fuel leak on a aqua hot (Understand they are the same pump unit) on the Monaco plastic we had. I found the seal on the pump shaft had failed. A few drips while turned off and a LARGE leak while running.

[MangoMike]

Ray,
I've been out of touch for the last couple of days, so missed your post.

I had the same issue with mine leaking. After a couple of days of trouble shooting I just gave up and purchased a new fuel pump which solved my problem.

I also installed a fuel shutoff valve on the supply line to the Webasto so in case of future problems the fuel can be cutoff.

pump_4974.jpg

pump_4972.jpg

pump_7205.jpg

pump_7209.jpg

Pump was $177 from thermo king Roanoke,Va Ken parts
540 343-1528

[Ray Davis]

Mike,

Thanks for the info. I'm really hopeful that it is the pump. I've made contact with a dealer semi-local, and plan on going there tomorrow to get parts.

Was this the unit on your H3 that was leaking, or on your Mothership?

Ray

[Ray Davis]

PS: Where did you place the fuel-shutoff valvle? Inside the case for the Webasto, or external before the unit?

Thanks again,
Ray