have some issues with drott40 with Detroit. Runs and screams and then looses power. I am sure its fuel. Removed fueltank and cleaned. Replaced the fuel lines. Added an inline electric fuel pump. When I check the filters they are empty. What kind of fuel pump is on this engine. I think the issue is there. This is an old farm used machine and works well till I lose power. I am new to this site, but use the forestry forum site where lots of old equipment is talked about. Any help appreciated and u have my permission to email me [email protected]
Your fuel lines should run from the tank to the primary filter, from the primary to a small gear pump on the front of the blower. Then from the pump to the secondary filter. The secondary filter feeds to the cylinder head. If both filters are empty you have a suction leak somewhere between the pump and tank. If you have canister filters you have to have new gaskets on the cover and hold down bolt after you open them up. Most common air leak I've seen on Detroits. Also that electric pump is more than likely impeding your fuel flow, Detroits move a lot of fuel and most ticky-ticky pumps don't keep up.
thanks, am sure is an air leak (somewhere). The electric fuel pump is a 35 gph I use on my 585 cu in MM engines. No problems. Is the Detroit that many cubes? I wonder about the gear pump on the Detroit. Is it problematic? I eliminated the fuel tank and drew fuel from 5 gallon buckets and did return that way also. Know its not a plugged tank or collapsed fuel lines. (cleaned the tank and replaced the lines.) Did replace the fuel filters and gaskets. (doesn t mean I still do not have a leaky gasket.) What about be passing the engine gear pump using the 35gpm electric fuel pump?
Which engine do you have? Have you put the return line in a bucket of fuel looking for bubbles? To check the gear pump you need to check how many GPM your getting out of the return line (gallon container and stop watch) Some of the 12V71's could pump an easy 1+ GPM at 65 PSI at the heads, which is why I have little faith in the electric pump idea. I have seen pressure regulator valves in the gear pumps stick, but that wont empty the filter housings. My next step would be to pressurize the suction side from the tank to the pump with air and spray with soapy water looking for bubbles at joints.
Detroits use excess fuel as a means to cool the head and injectors, the electric pump is likely in the way as RZ just said. Look carefully at the steel lines, after 40 years of service they can and will crack.
thanks will try that after get the first crop hay off. And unstick a stuck big case IH and a discbine mower.
Drott 40's use a 4-53 engine. I believe you are looking at an air leak. Many moons ago I cobbled a clear return line to troubleshoot that. If you are bleeding the system, starting, then it dies, look at the return line fitting at the head. It is a restricted fitting to keep pressure in the head. Probably a piece of useless information.... a 53 Detroit uses a gallon per hole per hour, under full load, and at low idle I think it would run on a teaspoon. Just curious, what series of 40 is that?
The mechanical gear pump will stop the electric from feeding past, is a PDP gear pump and will not give a hole to flow thru.. If you manage to get full fuel flow to that head and the orifice is GONE(dimwit replaced restrictor fitting with regular) it will flow much of it BACK to tank, outlet fitting on head should have a restrictor fitting or drilled plug IN it, roughly 1/8" hole. Check as noted for sucking air, clear tube outlet of primary to pump first and if solid then secondary to head, may have a supply pump sucking air with seals gone bad where feeding that with a tika tika pump will flood the crankcase eventually. These little buggers enjoy running away, don't give it a free chance.
that 40 should have the 471, my 1979 40D did.First check the rubber fuel lines from the tank which are real close to the batteries and can easily get under a battery, don't ask how I know
Is the Detroit that many cubes? The 53 series Detroit is 53 Cubic inches per hole, The 71 series is 71 cubic inches per cylinder. To ID your engine if no tag on it an easy way is to look at the valve covers. A 53 series has screws around the valve cover to secure it to the head. The 71 series will have big thumbscrews thru the top center of the valve covers. Then simply count the cylinders i/e 3-53, 4-53 Etc. I wonder about the gear pump on the Detroit. Is it problematic? The gear pump is normally not problematic. They are very reliable. The only issue you ever see for the most part is when folks remove them and lose the little square drive coupling. What about be passing the engine gear pump using the 35gpm electric fuel pump? Your 35 gal per minute pump will not hold a candle to the gear pump. Plus the gear pump boosts the fuel pressure to 60-65 PSI. The primary filter is not designed for that kind of pressure but for fuel suction thru it. My guess is you have a vacuum leak or perhaps a collapsed internal fuel line before the pump. The suction can plug a old fuel line by folding the internal rubber lining inside the line. You could run a fuel line from a clean source directly to the gear pump intake and segregate the rest of the fuel system back to the tank for trouble shooting purposes.
thanks to all of you for good information. This is on my project list after I get my shop empty. Every time I get a tractor problem fixed and move it out of the shop a vacuum is created and when I open the overhead door it sucks in another project . Good thing the trackhoe is outside at another farm. Fuel lines were replaced and (tied up) above the batteries. Now I need new batteries. Will try removing the inline pump. I do have fuel flow the tank. Good old off road diesel smell. Will check the steel lines at the filters and the gasket seals. Could the gear pump be (partially working)? Again thanks of all the info. I am learning lots about the Detroit...….now were did I put my earplugs and ear protection. No, way I can start the old girl and the neighbors a mile away not know.
PDP style gear pumps work or don't, they get enough wear to not displace the fluid being pumped and generally get to a point of recirculating inside the pump housing. These are no different, much of the time on Detroit's the drive coupler fails as the pumps lock up as common failure then will NOT run. Still sounds as sucking air or starving. As a side note, winter of 1983 0r 84 a piece of used fire apparatus was being driven thru my area of the country. Was at my regular job got the call would run and die run and die, boss sent me out with a replacement fuel pump for a 6L71 which was in it. Spent a couple hours in below freezing weather hands coated with fuel swapping pumps under a non lifting cab working thru access panels and getting same result where re-installed Old pump. Spent a LOT of time warming myself in the fire hall where the machine was sitting in the parking lot in St. Peters MO. Finally grew that brain cell and started following the fuel line back to tank(Ladder Truck), engine in front, fuel at farthest rear point. Long story short, as wriggled down thru a ladder storage rack found a crushed section of metal fuel line under a rack support cross member that had failed, totally invisible from anywhere but INSIDE that damn ladder storage rack pocket UNDER the hose lay storage floor and above the drive train between frame rail and body. Spliced in a section of 1/2" rubber fuel line around that crushed point and VOILA!! Success! My hands/fingers have not been warm since in the winter.
Many year ago I worked at a coal mine that had a fleet of 40 Terex trucks powered by 16V-71 engines. I lived about 5 miles away as the crow flies and on a cold winter's evening standing at the front door of my house I could hear every truck coming out of the hole. Amazing considering that the mine was down a 150ft deep hole with big earth banks all around it to "muffle" the sound to the surrounding communities.
As DMiller noted, the pump is pass or fail usually. Once in a while you will see one that leaks on the shaft seal at the drive side. It can suck air at that seal. You normally can see fuel residue there if it is bad. I don't believe that is your problem because it sounds like it starts and runs until the filter is empty. I think the problem is either the primary filter gasket or somewhere on the tank side of that.
Found the issues with my Drott 40, with Detroit engine. Followed all the advice given me last summer on here. Took me time to get back to the Hoe issues. Unhooked all the fuel lines, opened bleeders, air checked for plugs and leaks. Took out the inline electric fuel pump. was blockage (crud) in the elbow under the fuel tank. Removed and cleaned completely. Reinstalled and cranked and (old guy helper in a can sprayed on air intake). She started to scream and sounded like, looked like and acted like a "sreaming Detroit" Had her tracking at a High rate of speed (turtle passed me). Also rebuilt the top cylinder. Now adding about 25 gal of hyd oil. she holds 55 gal. Time for a lube job and grease and tighten the tracks. Now this old guy can get on that young machine and move a hill.