Fuel vent

[snoplay]

After driving for awhile my M35 fuel tank builds pressure, when I stop for fuel and release the cap it can spray you ,is this pressure normal ? it does have a non-vented cap
Thanks

 

[gimpyrobb]

Doesn't sound good to me. The fuel tank and airpack are usually vented together at the "slobber tube." There is a PS article about seperating them as the fuel fumes eat the airpack seals. Maybe the Slobber tube has gotten plugged and the airpack is venting into the fuel tank. The "T" where the brake lines and fuel lines meet is under the passenger on the frame. I am geting ready to do this myself.

http://www.steelsoldiers.com/index....rpak_vent&name=gallery&include=view_photo.php

 

[snoplay]

Thanks I"ll ck it this weekend

 

[Beerslayer]

I had the opposite happen, when I stopped to fuel, I could hardly get the cap off of the tank, there was such a strong vacuum.

A friend came over and we pulled all the lines loose and blew them out with compressed air one by one. Did NOT blow on the one to the brakes.

They were all clear for the most part. I then pulled the fitting on the top of the fuel tank. It was plugged solid. Here's the mystery, it took about 10 minutes to get it cleared out with drill bits. The substance that came out looked almost like JB Weld or Permatex gasket material.

What I don't understand is why I had no problem with this issue before a month ago. I have made many 200 mile runs with this truck, stopped to fuel, and no vacuum on the cap, but this gunk looks like it has been in there a while.

The first photo is of the fitting before cleaning, the second photo shows some of the gunk on the drill, and the third photo shows the fitting after cleaning, and note the chunk of material lying on the fuel cap. That was some of what came out of the fitting.

I can't imagine a circumstance where someone would deliberately plug a fitting like that but I don't understand how it came to be like that.