After seeing the fuel gauge mounted inside the door by the fuel filler, I started thinking about how difficult this would/would not be to do.
Anyone know what it takes to add a fuel gauge to a 4108 that did not have one installed at the factory? Is this something that can be done without removing the tank? If so, any information on the necessary sending unit - which one and how to install?
Haven't really needed a fuel gauge yet, but I can see where it could be handy to have one. Certainly easier than using a dipstick to check fuel.
Your wiring diagrams should have one listed for that option. You will need a push button or momentary switch for it.
Wiring I'm not worried about - it's the fuel sending unit I'm not sure about. I looked in both the parts book and the manual and see nothing about where the sending unit goes or what the parts are that would be required.
You tap into the one that is already in the tank. That is why you use a momentary switch. It disconnects the wire going to the dash unit while at the same time connecting to the gage at the tank.
Quote from: chessie4905 on October 20, 2018, 02:28:28 PM
You tap into the one that is already in the tank. That is why you use a momentary switch. It disconnects the wire going to the dash unit while at the same time connecting to the gage at the tank.
Therein lies the problem...I don't have a fuel gauge at all. Not in the dash, not at the tank. I'd have to start from square 1 by installing the fuel sending unit.
When I saw the option of just mounting a gauge at the tank filler door it occurred to me that it might be possible to do the same. If it's possible to install a sending unit without pulling the tank I'm interested.
I have an accurate fuel gage on my bus and i am happy to have one. So i am encouraging you to install one. The owner was just finish to install it whent i purchase the bus. I dont know if you have the space over the fuel tank to make a hole in your floor to have access to the tank. If yess that will be easy. If not,the tank will have to com out. Wich is a good think after all,you can clean it and inspect it while in the process.
Safe thing to have.
Not that hard to pull. I pulled mine to change to longer tank
Quote from: Templar52 on October 20, 2018, 02:55:23 PM
I have an accurate fuel gage on my bus and i am happy to have one. So i am encouraging you to install one. The owner was just finish to install it whent i purchase the bus. I dont know if you have the space over the fuel tank to make a hole in your floor to have access to the tank. If yess that will be easy. If not,the tank will have to com out. Wich is a good think after all,you can clean it and inspect it while in the process.
Safe thing to have.
Our actual mileage has ranged from 8.5 mpg on flat ground w/o the generator to as low as 6.5 mpg in the hills/mountains or with generator use while camping. Tanks holds 165 gallons. Figuring a safe useful capacity of 145 gallons, we have a range of between 942 and 1232 miles. Right now my 'fuel gauge' consists of a yellow sticky note on the dash where I write down the odometer reading 600 miles beyond the most recent fill up. Setting our fill up point at 600 miles gives at least a 342-mile buffer to find a station before we chance having problems. That said, it would be nice to have a fuel gauge.
I just went and took a close look at what's there. Just to the right of the fuel filler neck is a cast metal cover. Looks like it could be a place a sending unit could be mounted, but I haven't figured out exactly how to tell. There is a hatch in the floor directly above this area about 9"x9". Problem is that the area above it inside the bus is where the drawer base for the built-in couch sits, with a doubled plywood support running directly across the top of the hatch plate. It would require cutting away a piece of the plywood support to be able to get the hatch out. Maybe something I'll explore in the spring when it's warmer and things are easier to work with.
Quote from: chessie4905 on October 20, 2018, 03:03:21 PM
Not that hard to pull. I pulled mine to change to longer tank
Perhaps it wasn't that hard to pull for you. My shop at home consists of a gravel lot and I'd be doing this alone. My experience with things like this is that if it's not broke don't fix it - the tank is clean (just recently checked) and has no leaks or other issues. I'm very hesitant to pull it for something that is really a luxury item.
Where does the fuel sending unit mount on the tank? Some of these buses came from the factory with a gauge, so there must be a place for one to mount - anyone able to point me towards it? Even better, photo or scan of a manual page would be great.
Surprised that I can't find anything about this in the manual or parts book. Wouldn't be the first time I missed something, but damned if I can find it.
Fuel gauges are nice to have,I was driving across Or one night when the clamp broke on my cross pipe (Eagle with 2 tanks ) I filled up in Boise when I reached Jordan Valley Or about 70 miles I notice I used a 1/4 of tank of fuel.I told my wife damn this 8V92 has never used this much fuel before,we stopped at truck stop In Jordan Valley I had fuel pouring.I would have never knew I had a problem without a gauge,no smell and I had plenty of power lol the Jeep was covered and dripping fuel
It mounts on top of tank it has 5 offset holes the sender sets on a 5/8" raised circle in from passenger side of coach. To remove tank, you need to disconnect filler neck, 8 -1/4" bolts. Disconnect fuel line. The tank is attached to 6or 7 small cross members that have straps attached that go up around tank. To remove tank you remove 12 or 14 3/8th inch x 1 or 1 1/4 bolts that attach these crossmembers to channels that tank rest on. The heads of these bolts point to the ground under coach. Once you remove the bolts, you can slide tank out driver side of coach by opening HVAC door. You don't have to mess with the straps, as it is sort of module designed. I believe it is a 90 ohm gauge. Standard 5 hole mount, single pin.
Oh, don't attempt this with fuel in tank. There is a 3/4 inch?? Brass hex drain plug on bottom of tank on pass side.
We added a fuel gauge to our 4104 right after bringing it back home to FL from CA. In TX my wife asked "when was the last time we fueled up?'' About 20 min. after that question we ran out on I-10 middle of TX. We ran the 5 gal Gerry can back & forth to a gas station with the Jeep toad 25 miles down the interstate 3 times. We never got it to start. Knowing well where the station was we hooked up the toad to the bus & pushed it with the Jeep (had a high performance V8) to the station. We had 2way communication - that helped a lot. As we exited the off ramp a TX Hwy Patrolman came in behind the Jeep with his pretty blue lights on. Looking in my side views I can see the officer exit his cruiser walk around the back side of his car & up the passenger side eyeballing the wife in the Jeep & heading to the bus front door.
Keep reading, this gets good! The year was 1982. I has a full head of hair down to my waist and a beard that covered the chest. As the officer approached the door I swung it open from the dash & almost knock him over - when he saw me sitting there, his hand went down to his holster & unclipped his fire arm while simultaneously telling me that he had to site me for illegal towing a person in the toad. My response was I'm not towing her officer she's pushing me, "we're out of gas". To shorten up this memory - when the cop knew what was going on - cool engine on the bus & hot engine on the Jeep he turned into our best friend & escorted us into that gas station (not the police station!) waited for us to fill & asked us if there was anything else he could do for us. I mentioned to him a real long parking lot would help because I may need to push start the bus after I kill the batteries trying to get it primed again. He escorted us to a large mall parking lot. Once we got it started it didn't run as good as id did for days after that while still finding air trapped in the system. So Richard putting in a fuel gauge shouldn't be a real problem & we think its a good idea. ::)
I suppose it's different with the GM, but our MC5a also did not come with a factory fuel gauge. However, the wiring was there as well as a round plate where the sending unit would go. This was easily accessible by removing the side panel by the tank since the hole was on the side of the tank. If yours is on the top of your tank and you know where the access port is, it would seem that cutting an access to the port through the plywood using an oscillating saw would be simple.
Richard -
It seems that the only busnuts who run out of fuel are those with a fuel gauge! :o
I advocate and adhere to a strict "500 mile" rule, and I use the "A" trip meter of our Garmin gps to keep track, resetting it every time we fuel the rig. Even with your additional fuel capacity, I'd still stick to the "rule."
Do you have the stock dashboard in your 4108? Is there a blank space for a fuel gauge? Been awhile since I've seen that dash panel, so I don't remember. If you don't have a spot, where will you install it?
Don't forget - you'll need a 24vdc sender and gauge for the project, should you proceed.
There's my 2ยข worth for you to ponder.
FWIW & HTH. . .
;)
Fuel gauges work from resistance the voltage is usually for the lighting on the gauge ,some of the buses have a Moller or Rochhester at the tank that requires no electrical
The GM sending unit is 90 ohms, a standard resistance they used to have on all their fuel sending units, cars, trucks,busses,coaches. Nowadays all different.
Ok, I went down and looked. Above the fuel filler is a plate of plywood and linoleum with phillips screws in it. I had to remove couch away from cover and pull back carpet when I changed tanks. From that access, you can see if there is a blank plate with 5 holes, 2 3/4 in diameter. If you have this, you just need to purchase the sending unit and can most likely insert it down into tank. If you dont have it, you would need to pull tank and have a blank mounting plate soldered, not brazed or welded, to tank. Everything can be disconnected from top of tank through this holeAn older radiator shop should easily accomplish this.The sending mounting plate is just to rear of rectangular fuel filler unit, and centered on top of tank front to back. I have the short tank from this coach and one in the parts coach and neither has a block off plate, so likely, yours is the same.
The tanks are 32 inches tall. The sending unit is stamped on resistor hsg 90 ohms. The round top with 5 off center spacing holes is 2 3/4" diameter. The rigid stem that sticks down into tank is 16" . The float arm is 19" pivot point at resistor to tip of float. Max down 31" , max up 1/2" below underside of float mount. Single threaded post on top.
I found this so you could mount to top of tank without soldering. Because the sending unit holes are offset, make sure to index correctly when installing ring. I recall that the baffles in tank are slotted for swing of float.
https://www.amazon.com/Auto-Meter-3263-Level-Adapter/dp/B006VNGWI4/ref=pd_sim_263_4?_encoding=UTF8&pd_rd_i=B006VNGWI4&pd_rd_r=28cce7d6-d574-11e8-b4fc-6babf8f7cd8b&pd_rd_w=kt9Rr&pd_rd_wg=qpJ8S&pf_rd_i=desktop-dp-sims&pf_rd_m=ATVPDKIKX0DER&pf_rd_p=18bb0b78-4200-49b9-ac91-f141d61a1780&pf_rd_r=NYCHTDNK1KWB0Y1G941B&pf_rd_s=desktop-dp-sims&pf_rd_t=40701&psc=1&refRID=NYCHTDNK1KWB0Y1G941B
I don't think I've got the plate on top of the tank. I do have a piece that I can't identify on to of the tank. It's circled in red.
The extra fuel lines on the side of the tank are for the generator.
That is the tank vent. The fuel sending unit plate would be just to back side of fuel filler mount.
In that case, sounds like a hole will need to be drilled to mount the sending unit. Since the pivot type sending units must line up perfectly with the slots in the baffles, I'm not sure how to know where to drill.
Then there is this type of sending unit: http://www.rochestergauges.com/products/9800Marine.html
Looks like they can be had in 4" to 42" lengths, so size should be no problem for the depth of the tank. The hole is a standard 5-hole mount, so I could probably mount it to the tank without soldering by using one of these: https://vwparts.aircooled.net/VDO-Fuel-Tank-Sending-Unit-Mount-Kit-Bolt-In-p/v226451.htm
If I can gain access to the hatch over the tank by going through the base of the couch above it, it looks like the whole thing can be done without pulling the tank. Looks like the only thing would be making sure I avoid drilling over a baffle.
How do I know where the baffles are? Will there be a visible marker on the outside of the tank? Or are they all a uniform distance from the passenger side end of the tank? Or is it only by putting a scope in there will I know?
No problem on the baffles. They are placed in the tank where the straps go around the tank, obviously to keep from collapsing tank when straps are tightened.
I prefer the mount I referenced as it is mounted to tank separate from sending unit screws , but do it your way. You can cut a hole with a hole saw to the idor slightly larger of mounting ring. If you load it with grease, it should catch the chips. If you need, I can give you the dimensions where my factory sender is located.
If I was doing it, I would remove the fuel filler neck. That way you can see what you have on the inside of tank when placing sender. You could put a strong magnet inside top of tank to catch any loose chips.
Quote from: chessie4905 on October 21, 2018, 04:55:36 PM
...If you need, I can give you the dimensions where my factory sender is located....
That would be really helpful when you have a minute to check. Thanks.
Threaded electrical stud ( 1) ,11 1/8" in from passenger end of tank. Looking through fuel door stud is approx 5/8" to the right of plate fuel filler neck is connected to. The mounting flange for fuel sender just clears plate and round plate that fuel pickup is connected to. ( it looks like the fuel sender mounting plate, but all bolt holes for it are evenly spaced, and on both my tanks, the plate and screws are soldered to tank.