| Author | Message | ||
| Robert Chamuler (Nemos88)
Registered Member Username: Nemos88 Post Number: 8 Registered: 8-2006 Posted From: 76.104.145.36 Rating: N/A |
I have a 1955 TDM 4515 that is new to me. Got it started today for the first time. It ran fine for about 20 minutes and then it just stopped. The emergency stop flapper was not tripped. It would turn over but not restart, even with starting fluid. What things should I look for? Also the fuel in the tank was very very low, I was in the process of pouring fuel in the tank when the engine stopped. I am thinking it may have drawn up some air as the tank was low on fuel and lost the prime, but could there be another reason for it to have stopped? Thanks in advance for your comments. | ||
| Cameron Jones (Crazy71)
Registered Member Username: Crazy71 Post Number: 32 Registered: 12-2006 Posted From: 75.179.153.89 Rating: N/A |
The only time my 8v71 would not start with starting fluid was when the flapper was closed. When I ran mine out or fuel...both times (takes me a couple of times to get the point) it fired up on ether until it ran out. I learned that mine won't prime itself..despite what I have heard. Since you think it ran out...you need to prime it anyway...you can pull the filters off and fill them with diesel then prime with a electric pump or a hand pump or pump up sprayer. Mine has a fitting on the filter block with a screw on cap on it. I just stick the hose onto it and pump diesel into it for about 30 seconds. | ||
| Chuck Brush (Chuckbrush)
Registered Member Username: Chuckbrush Post Number: 29 Registered: 1-2007 Posted From: 64.12.116.130 Rating: N/A |
Hi Robert, Glad she started. Guess which TDM 4515 this is? I am officially placing Mr.Chamuler in your hands. There will be no driving down the grapevine for the boys from Texas, not this year anyway. Thanks all for your kind help. Chuck | ||
| Glenn Williams (Glenn)
Registered Member Username: Glenn Post Number: 32 Registered: 6-2006 Posted From: 207.179.92.61 Rating: N/A |
Talk about timing! I was just going to do a search on how to prime an 8v71, and here was the post! I used the fitting on the fuel filter housing, put a hose on it and attached an old re-fillable fire extinguisher filled with diesel. Worked like a charm! Thanks guys! | ||
| Robert Chamuler (Nemos88)
Registered Member Username: Nemos88 Post Number: 9 Registered: 8-2006 Posted From: 207.225.232.131 Rating: N/A |
On a 6-71 what occurs at the fuel rack when the key is turned off. Is there anything I can check on the engine. The reason I ask is that I am thinking that running out of fuel was not the problem. The wiring on my bus is a disaster and I am wondering if the problem is electrical or air related. | ||
| Jim Wilke (Pd41044039)
Registered Member Username: Pd41044039 Post Number: 127 Registered: 2-2001 Posted From: 69.77.151.82 Rating: N/A |
Robert, If priming the filters gets her started, but she shuts down again after running 5 minutes or more, something may be allowing air pressure to the rack shutdown piston. With no air pressure, the rack sits at idle speed when the engine is running. Whe the shutdown air cylinder is activated, it pushes the rack slower than idle to the point where the engine stops. (When the air pressure bleeds down, the rack returns to a run position, actually near full throttle till the engine starts & the governor forces the rack back to idle.) IF air is activating the cylinder (located on the right side of the bus on the rear of the cylinder head) then something is deactivating the "run" solenoid valve or it is leaking. It would likely be an electrical problem. If it shuts down "without your permission", immediately loosen the hose fitting a little at the cylinder. If there is air pressure there, start by checking to see if there is 12 volts at the solenoid valve. Get someone to switch it from "Run" to Stop" a couple of times while you observe if the air flow turns on & off. Also check that when the air is not flowing, that it isn't leaking a tiny bit. You can put the hose end in a glass of water to see if it bubbles. If it bubbles a little, that could build enough pressure to stop the engine. (but it would "peter out", not abruptly stop.) (The valve is normally open and closes when you switch the Engine Run toggle switch on at the dashboard.) That's why you can start the bus with no air built up, switch it off, but it won't shut down until the system builds up some air pressure, (This normally takes only about 3-5 minutes.) which makes the engine slow down, then die. If your pattern of shutdown continues, you can put a 1/4" "petcock" type valve in line at the shutdown cylinder. This will allow you to close that valve and the engine will not stop till you open the valve. This will get you home but is not a long term fix. Someone did this on my 4104 long ago & I never took it off. (This is an "emergency override" for the entire run/stop system in case you have a problem where it shuts down on the road somewhere.) Jim-Bob | ||
| Robert Chamuler (Nemos88)
Registered Member Username: Nemos88 Post Number: 10 Registered: 8-2006 Posted From: 76.104.145.36 Rating: N/A |
Thanks for the info Jim. The bus is about 150 miles away from me in Ocean Park Washington. I will check the stop cylinder the next time I go over. When it shut down it did not sputter or slow down it just stopped, that makes me think it may not have run out of fuel but stopped do to the stop cylinder activating. But as I removed the filter I am sure I have lost the prime and will have to re prime. It would be nice to get her home. These 300 mile round trips are getting old. | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 312 Registered: 11-2005 Posted From: 63.97.117.11 Rating: N/A |
On my 4104 w/671 there is a switch for mechanics to use to cut off the engine from the rear. If this is accidentally bumped it will do just as you said. It is easy to bump off when starting the engine from the rear. Don't ask me how I know this! If this switch is off the engine will start easily, run nicely until air pressure builds up-then stop! There are four switches there. One to take the starter out of the circuit so it can't accidentally be started, one to start the engine, one to shut off the engine and one for the compartment light. These are located high on the right side of the engine compartment. | ||
| Chuck Brush (Chuckbrush)
Registered Member Username: Chuckbrush Post Number: 30 Registered: 1-2007 Posted From: 205.188.116.13 Rating: N/A |
Hi Robert, Rodger had to mess with the air compressor regulator in order to get the bus to run right. If there is an air pressure problem I would look there. Also I was told that there was no power to the coach which would jive with what another poster said about the switches on the firewall. If the pressure controler is the problem I was planning to adapt a D-2 type governor. They are less than $20.00 and all the ports are labeled. Chuck | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 316 Registered: 11-2005 Posted From: 63.97.117.34 Rating: N/A |
Chuck, I don't think no air pressure is his problem, this shouldn't affect the engine running. The problem with air is after the pressure builds up and the switch in the rear is on, then the air pressure shuts off the engine. 12 volts from this switch to an electric valve allows air into the small air cylinder which closes the fuel rack, it will keep running as long as there is no air pressure to shut it off. If there is no air press the air valve opens but there is no air pressure to close the air cyl. When the engine shuts off and there is no more air to the small cyl a spring opens the rack again so it will start next time even though there is no air pressure. This may not be exactly how it works but it is close. It has been a while since I went through this very frustrating experience!! | ||
| Robert Chamuler (Nemos88)
Registered Member Username: Nemos88 Post Number: 11 Registered: 8-2006 Posted From: 76.104.145.36 Rating: N/A |
When I was last over at the bus I noticed that there are not any switches in the back. There is a wiring panel on the left rear that does not have a cover on it. Roger the previous owner, shimmed open a solonoid on the rear firewall to get it to run. I am thinking could this be the solonoid that controls the rack to shut down? I did mess with the shim on the solonoid when it was running and shortly thereafter it stopped. The solonid has I believe 3 air hoses running to it. I wish I had taken a picture of it when I was there. This bus is a 1955 TDM 4515 so I am not sure if the engine compartment set up is the same as most of the 4104 and up buses on this site. | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 108 Registered: 8-2006 Posted From: 207.231.81.22 Rating: N/A |
A sign in a shop: $25/hour labor rate. $30/hour if you watch. $35/hour if you help. $50/hour if you worked on it first! A humourous way to express frustration over our not having a clue. The stop cylinder on the engine will only have one hose to it. I guess there could be a tee on the supply side of the valve, which would account for the 3rd hose, if it is the shutdown valve? Simple solution, disconnect the hose to the shutdown cylinder, and see if the engine starts and runs! Good luck, George | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 317 Registered: 11-2005 Posted From: 63.97.117.14 Rating: N/A |
The rear switch panel is high on the right side (Passenger) of my '54 4104 and I assume your '55 4515 has the same setup since they are only a year apart and have the same engines. On the left (Driver)side down lower is an electric solenoid which is the emergency engine stop. It has a pin pointing down which when raised out of a notch in a cam (The cam is spring loaded)will release a large flapper valve which will shut off air to the engine. If you messed with a shim and released this cam there is no way the engine will start. A photo of what you are talking about would make this much easier. | ||
| Robert Chamuler (Nemos88)
Registered Member Username: Nemos88 Post Number: 12 Registered: 8-2006 Posted From: 76.104.145.36 Rating: N/A |
I am familiar with the emergency shutdown flapper. It was not tripped but I did check it by flipping the swith in the drivers compartment and it did work fine. After checking that it worked I reset it. The solonoid I am talking about is on the firewall. I am going down to the bus on Sunday and if I do not get it running I will take some pics of the solonoid in question. | ||
| george bruton (Tazman632000)
Registered Member Username: Tazman632000 Post Number: 7 Registered: 2-2007 Posted From: 65.184.183.4 Rating: N/A |
CHECK TO MAKE SURE THE BLOWER IS SPINNIG I JUST BOUGHT A 4106 WITH A 8V71 AFTER 250 MILES THE SHAFT THAT SPINS THE BLOWER BROKE. THE FUEL SYSTEM IS MORE OR LESS SELF PRIMING | ||
| Cameron Jones (Crazy71)
Registered Member Username: Crazy71 Post Number: 46 Registered: 12-2006 Posted From: 75.179.153.89 Rating: N/A |
How do you check to see if the blower is spinning? | ||
| Robert Chamuler (Nemos88)
Registered Member Username: Nemos88 Post Number: 13 Registered: 8-2006 Posted From: 76.104.145.36 Rating: N/A |
Well I got it running, it was the solonoid that controls the rack. No power to it so I shimmed it. I will try to post of picture of it. | ||
| Robert Chamuler (Nemos88)
Registered Member Username: Nemos88 Post Number: 15 Registered: 8-2006 Posted From: 76.104.145.36 Rating: N/A |
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| Robert Chamuler (Nemos88)
Registered Member Username: Nemos88 Post Number: 16 Registered: 8-2006 Posted From: 76.104.145.36 Rating: N/A |
Gus, I found the switches that you were talking about. they were under the wiring panel on the left bulkhead. I will need to replace all of the switches however as they are corroded. Are they standard double pole switches? | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 320 Registered: 11-2005 Posted From: 63.97.117.26 Rating: N/A |
Robert, Three of them are single pole single throw except the starter switch, it is single pole single throw momentary. This means it cannot stay in the start position. This is very important-mine isn't and I accidentally left it in the start position once and almost destroyed the starter. Changing it is on my list. I found momentary switches at a marine store at very reasonable prices. They are usually found at aviation supply places at outrageous prices. By the left side I assume you mean the driver's side? This means they were moved from the right side. Don't see any reason to do this but I long ago ceased to be surprised at anything I find on these buses! | ||
| Robert Chamuler (Nemos88)
Registered Member Username: Nemos88 Post Number: 17 Registered: 8-2006 Posted From: 76.104.145.36 Rating: N/A |
Gus, Thanks for the information on the switches. The panel in the rear is on the passenger side, the radiator is on the drivers side. Looks like the original location. | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 326 Registered: 11-2005 Posted From: 63.97.117.11 Rating: N/A |
Robert, Drop me an email if you have any more questions. I've spent a lot of time on the electrical and clutch systems. My son worked at the Renton Boeing plant for a while, he's now in Everett. I'll be driving out to visit him the end of next month or early May with the 4104. |