Nothing Special Posted June 17, 2020 Share Posted June 17, 2020 .... I would have a truck depot or tire specialist install stems you can actually get to. The problem with stems that work on the outside duals is that they really wouldn't work on the inside duals (or the fronts). So if you go that route you are kind of locking in where each wheel needs to go. No biggie if you don't rotate tires I guess. Link to comment Share on other sites More sharing options...
Rembrant Posted June 17, 2020 Author Share Posted June 17, 2020 What about a stint? Push a piece of tubing in that will open up the other tubing? Gary, I just put 40 gallons in that fuel tank yesterday morning, so anything that saves me from having to drop it I will most definitely try...lol. So my new fuel sending unit arrived today, and in looking at it, I discovered what my problem is...although I'm still a bit confused...lol. And here it is... Three fuel lines...or so I thought. Two for the 460EFI (one supply, and one return), and the 3rd smaller line to feed the onboard Onan generator. Except...it behaves exactly the same as the sending unit currently installed in the RV. I can blow through the small line (with force) and cannot suck on it at all...it is blocked. So I follow the line down to the pump housing that sits on the floor of the tank, and it just elbows into the top of the housing. Fine. So I pop the fitting out of the housing, and low and behold the stupid thing has a duck bill on the end of it...or, effectively a check valve...so no wonder I can't pull any fuel from it. So this new replacement unit has the exact same issue as the one currently installed in the RV. The seller said he had replaced this unit in the past few years, but since the generator was inoperable, he wouldn't have known that the line was blocked. I called the manufacturer (Spectra Premium, here in Canada) and Mr. Tech support tells me that this unit is not for RV's, and that this 3rd line is for emissions or fuel vapor return or something he wasn't too sure about. The interesting thing about that is, this duckbill is exactly where a generator fuel pickup should be...approximately at the 1/4 full tank mark, so that it doesn't drain the tank completely and leave you stranded while camping. So I guess I can probably just pull my existing unit, and remove the duck bill from the end of the line? As far as I know, there are no emissions lines laying loose back there that connect to this fitting....and even if there were, then where would the generator connect?...I realize this thing is 27 years old, but surely there still a lot of 460EFI RV's on the road with onboard generators? Link to comment Share on other sites More sharing options...
Rembrant Posted June 17, 2020 Author Share Posted June 17, 2020 The problem with stems that work on the outside duals is that they really wouldn't work on the inside duals (or the fronts). So if you go that route you are kind of locking in where each wheel needs to go. No biggie if you don't rotate tires I guess. I went over to a commercial tire shop here in the industrial park, and they confirmed that they usually install the valve stems just like they are on my RV duals (shorties, pointing inwards). He recommended the valve stem caps that stay on and you can check the pressure through them, plus the special reach pressure gauge that fits through the holes to reach the inner and outer stems of the duals. He said this is what their techs do for most fleet vehicles around here (with tire maintenance contracts). He said most people don't like the extensions because they're not overly reliable. I learned something new today! Link to comment Share on other sites More sharing options...
Rembrant Posted June 21, 2020 Author Share Posted June 21, 2020 The way to tell if there is no thermostat (or it's stuck open) is to check the top radiator hose from cold, or look down into the radiator while cold. The heater core is part of a bypass loop from the water pump. It should be fully warmed up before the thermostat begins to open. IF the coolant is flowing across the top of the core when cold, and/or the upper hose gets progressively warmer, you have no thermostat. The thermostat is a modulator, not an on/off switch, but it should not be opening at all until it reaches a threshold level. Gary has posted the resistor values to test the gauges. Jim, I still have to investigate the thermostat, but I have a new 180F one on hand and a new gasket, so maybe even today if I get all of my other chores done. Question: How does one know that the radiator clutch fan is working properly? What am I looking for? I noticed yesterday that it started to get a bit warm on the gauge while idling with the AC on full. DRiving down the road it seemed to be fine, so I was wondering if it was an issue of air flow when not moving. More testing to come... Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted June 21, 2020 Share Posted June 21, 2020 The way to tell if there is no thermostat (or it's stuck open) is to check the top radiator hose from cold, or look down into the radiator while cold. The heater core is part of a bypass loop from the water pump. It should be fully warmed up before the thermostat begins to open. IF the coolant is flowing across the top of the core when cold, and/or the upper hose gets progressively warmer, you have no thermostat. The thermostat is a modulator, not an on/off switch, but it should not be opening at all until it reaches a threshold level. Gary has posted the resistor values to test the gauges. Jim, I still have to investigate the thermostat, but I have a new 180F one on hand and a new gasket, so maybe even today if I get all of my other chores done. Question: How does one know that the radiator clutch fan is working properly? What am I looking for? I noticed yesterday that it started to get a bit warm on the gauge while idling with the AC on full. DRiving down the road it seemed to be fine, so I was wondering if it was an issue of air flow when not moving. More testing to come... I've never had a fan clutch give out and not drive the fan. I HAVE had them seize up, sound like a Sopwith Camel and take out the water pump. 😖 I'm a simpleton, with cheap and dirty techniques. Do you have a heat gun Cory? Can you try warming the clock spring on the front and see if the blade starts to lock with the water pump shaft? Link to comment Share on other sites More sharing options...
old55pete Posted June 21, 2020 Share Posted June 21, 2020 The way to tell if there is no thermostat (or it's stuck open) is to check the top radiator hose from cold, or look down into the radiator while cold. The heater core is part of a bypass loop from the water pump. It should be fully warmed up before the thermostat begins to open. IF the coolant is flowing across the top of the core when cold, and/or the upper hose gets progressively warmer, you have no thermostat. The thermostat is a modulator, not an on/off switch, but it should not be opening at all until it reaches a threshold level. Gary has posted the resistor values to test the gauges. Jim, I still have to investigate the thermostat, but I have a new 180F one on hand and a new gasket, so maybe even today if I get all of my other chores done. Question: How does one know that the radiator clutch fan is working properly? What am I looking for? I noticed yesterday that it started to get a bit warm on the gauge while idling with the AC on full. DRiving down the road it seemed to be fine, so I was wondering if it was an issue of air flow when not moving. More testing to come... The thermostat should be eather a 192 or a 195. As for the fan clutch, look for oil leaking around the shaft where it bolts up to the water pump and on the front where the spring is. If there is oil leaking or it is wet, the fan clutch is about to fail or has already. Link to comment Share on other sites More sharing options...
85lebaront2 Posted June 21, 2020 Share Posted June 21, 2020 The way to tell if there is no thermostat (or it's stuck open) is to check the top radiator hose from cold, or look down into the radiator while cold. The heater core is part of a bypass loop from the water pump. It should be fully warmed up before the thermostat begins to open. IF the coolant is flowing across the top of the core when cold, and/or the upper hose gets progressively warmer, you have no thermostat. The thermostat is a modulator, not an on/off switch, but it should not be opening at all until it reaches a threshold level. Gary has posted the resistor values to test the gauges. Jim, I still have to investigate the thermostat, but I have a new 180F one on hand and a new gasket, so maybe even today if I get all of my other chores done. Question: How does one know that the radiator clutch fan is working properly? What am I looking for? I noticed yesterday that it started to get a bit warm on the gauge while idling with the AC on full. DRiving down the road it seemed to be fine, so I was wondering if it was an issue of air flow when not moving. More testing to come... Cory, if it is like Darth's, at low speed it makes a bit of noise hot, start accelerating and you think you're in one of NASA Langley's wind tunnels up to about 45-50 mph at which point the rpm puts the clutch in freewheel mode. I always use a thermal clutch due to the monster fan so that I get full benefit of it at low rpm/speed, but aren't running it at cruise. Link to comment Share on other sites More sharing options...
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