| Author | Message | ||
| Brandon M (Brandon314159)
Registered Member Username: Brandon314159 Post Number: 49 Registered: 3-2011 Posted From: 173.8.221.225  Rating: N/A |
Quick question for some thoughts on a repair I need to perform. My '55 4512 has a fuel tank blockage I've been fighting for quite some time. It presents itself as low fuel pressure once every 100-200 miles and blowing compressed air backwards on the tank side of the check valve clears it for awhile. I looked through the body manual, and it doesn't appear that the dip tube comes out of the tank easily (located right by the filler neck on the passenger side). Anyone have any ideas? The tank isn't giving me black flecks like an algae or fungal infestation...just a hard blockage once and awhile. Anyone familiar if there is a screen on this pipe and if so...how to get to it? Thanks | ||
| ned sanders (Uncle_ned)
Registered Member Username: Uncle_ned Post Number: 118 Registered: 5-2005 Posted From: 184.39.28.28 Rating: N/A |
Had this on HUGGY when I first got her. Had to pull the tank and steam clean every thing out. She had been sitting for several years. uncle ned | ||
| Dal Farnworth (Dallas)
Registered Member Username: Dallas Post Number: 759 Registered: 7-2004 Posted From: 98.20.60.176  Rating: N/A |
According to the parts manual I have there is no pick up screen... but there is a check valve that can get plugged. I would drain the tank from the bottom and clean it well. Now blow all the crud back through the check valve, run some paint thinner or mineral spirits or carb cleaner through the lines to clear it out. Question: Are you sure there is no rubber hose between the pump and the tank? Old lines with the new fuel have a tendency to deteriorate. Good Luck to ya! Keep your stick on the ice! DF | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 2180 Registered: 10-2003 Posted From: 71.58.71.157  Rating: N/A |
One time on the 4104, I had a similar problem. Fuel filter appeared to plug up in short amount of time. Finally removed the tank to clean/inspect. Found a chunk of solder blocking pickup from some previous repair. Removed it and no problems since. While refilling tank, I added 5 gallons at a time and noted position of fuel gage each time I added and how much was left when empty/ 1/4, 1/2 etc. Kept it in records on coach. | ||
| Brandon M (Brandon314159)
Registered Member Username: Brandon314159 Post Number: 51 Registered: 3-2011 Posted From: 173.8.221.225 Rating: N/A |
DF, Check valve in the tank itself? I have the check valve @ the filters in the engine compartment. The fitting on-top for the dip tube is just a flared fitting. Line all the way back to my offical DD check valve & first filter is still stock steel. I was also suspecting the tank vent was plugged and thus pulling vac...confirmed the vent was clear. The short (2sec) burst of main air pressure seems to clear it out. Sounds like it is time to drain the tank and start flushing. | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 2184 Registered: 10-2003 Posted From: 71.58.71.157 Rating: N/A |
I cleaned mine with a gallon of kerosene, 2 quarts lacquer thinner and about 1 quart of small/medium gravel. (no fine stuff) Rocked tank back and forth several times daily over 4 or five days. Completely drained and flushed twice with a little kero; left air dry a couple days, Painted outside of tank and straps and reinstalled after making sure pickup was clean and in good condition. Nice not carrying 50 years of sludge around. While you are at it, make sure you didn't uncover any leaks (before painting, but after scraping away any exterior crud) in the process. If so, some radaitor shops will fix them. (pinhole or small)) | ||
| Buswarrior (Buswarrior)
Registered Member Username: Buswarrior Post Number: 2134 Registered: 12-2000 Posted From: 174.89.177.190  Rating: N/A |
This might be a place for one of these neat new cameras on the end of a flex tube? You'll be able to see what's going on in the bottom of the tank. Snap-On has them: http://www.youtube.com/watch?v=ORPbhf21i6k or try for cheaper alternatives.? happy coaching! buswarrior | ||
| Jack Fids (Jack_fids)
Registered Member Username: Jack_fids Post Number: 984 Registered: 1-2009 Posted From: 72.211.145.15  Rating: N/A |
Re: a cheap alternative... First guy to suggest a skinny guy with a flashlite gets a slap upside the punkin.... just sayin | ||
| RJ Long (Rjlong)
Registered Member Username: Rjlong Post Number: 1855 Registered: 12-2000 Posted From: 71.195.124.20  Rating: N/A |
Jack - "First guy to suggest a skinny guy with a flashlite gets a slap upside the punkin. . ." Did you feel it?  | ||
| Jim Blumenthal (Jimblu)
Registered Member Username: Jimblu Post Number: 25 Registered: 11-2008 Posted From: 208.168.236.12 Rating: N/A |
I use a rubber impeller pump with a hose through the filler to the bottom of the tank and pump the tank dry into clean 5 gallon buckets to inspect the fuel and what comes out. If the fuel looks good you can strain it and discharge into the tank with the pump and a hose with an elbow on the end so it sprays everywhere, circulating it for a while and then pump it back into the buckets to see if anything is coming out. I have a setup with a filter to protect the impeller. | ||
| Tim Brandt (Timb)
Registered Member Username: Timb Post Number: 632 Registered: 10-2003 Posted From: 66.165.176.62  Rating: N/A |
In the marine industry there are companies that would come out with a rolling rack of Racor filters and will just rotate the fuel until it's clean. | ||
| Dal Farnworth (Dallas)
Registered Member Username: Dallas Post Number: 761 Registered: 7-2004 Posted From: 98.20.60.176 Rating: N/A |
Jack - "First guy to suggest a skinny guy with a flashlite gets a slap upside the punkin. . ." Jack.. you are pretty skinny. I can loan you a flashlite! | ||
| Brandon M (Brandon314159)
Registered Member Username: Brandon314159 Post Number: 54 Registered: 3-2011 Posted From: 173.8.221.225 Rating: N/A |
Hey all, Quick update: I dropped the passenger side of the tank, removed the filler neck (only piece that un-bolts on this tank) and peered inside. What I found was multiple pounds of sand/silt/crust sitting a mere 1/8" below the bottom of the dip tube for the main fuel pickup. Most of this was contained to the area of the small 1/2" sump. I fashioned a vacuuming rig setup using a standard red 6-gal tank as a collection vessel and clear poly tube as my suction line. After about 1hr of vacuuming, the tank is looking pretty nice inside. Probably has never been done in 56 years. A side note, I measured the removed amount of fuel and found that I was down to the last ~10gal. Pretty impressive considering the coach was powering around town at this low fuel level (110gal tank total). Thanks for the words of wisdom. I'm still thinking of doing a small surge tank to avoid sucking air bubbles on hard corners. Do a 1 or 2 gallon tank with a 12V pump filling it, with a loopback to the tank return. | ||
| Brandon M (Brandon314159)
Registered Member Username: Brandon314159 Post Number: 56 Registered: 3-2011 Posted From: 173.8.221.225 Rating: N/A |
BTW, a photo for anyone who finds humor in these strange one-off setups :-)  |