The engine in my Clark TLB has begun to stumble at high RPM. The fuel filters were a mess and are now new. I've not ran the rack, nor had the valve cover off yet and just ordered a gasket today. The twin cartridge type AC fuel filter housings have 1/4" pipe plugs in them and I'll plumb in a gauge permanent. I don't know what fuel rail pressure at high idle should be? The engine runs very smooth at low rpm and stats easily when over 40 degrees, (F) outside. I don't know what rpm it starts stumbling as don't have a tachometer interconnected but I would guess 1400-1500 rpm. Thanks,
45-75 PSI , 35 min. at the head. 6-12 inches of mercury max at the inlet side of pump. Bob
Thanks Bob. I have gauges that will fit the bill on both suction and pressure sides. I don't have a "53" series inline book, but should get one acquired.
I was around alot of old Detroits one thing i can remember they would have a fuel suction problem alot. It was rare to start one that had been setting that would stay running after you went to alot of work priming it. I would take lines and filters apart not finding anything but it would fix it.
This one starts, idles, and revs up fine. No problems till attempting to get full power from it to drive. It then starts missing or starving out but recovers quickly. Not bogging, just feels like it's missing but only under high power demand. There were rust chunks in the primary filter, and some water, (I believe) in the secondary filter. Neither appeared plugged but there was a rust ring in the second cannister filter housing. Surface only and scrubbed right out but I'll bet the fuel tank is a mess internally. There are a few newer fuel lines feeding the filters. I think the discharge of the pump, and the outlet of the primary into the secondary filter is new but that's from memory. I'll pull a suction test on the supply side and monitor pressure as Bob relayed and go from there. The problem is most likely very minor and an internally swollen line is not ruled out. This biodiesel crap we're saddled with in the corn belt is hard on rubber parts of any age. Not really been around the 53 series much myself. More the 71 and a little 92 on generator set usage in years gone past. All good engines and the 53 is similar in many ways. I'll get some literature acquired for it also.
One thing I would be tempted to do would be to connect inlet to filters and return from head to a five gallon can with new hoses. That would be a nice fast way to rule out problems with the engine it's self. The only thing that could be missed that way would be a weak or leaking fuel pump, maybe bad pump seals. Also connect a hose to the return fitting and hold it in a can of fuel and see if there are bubbles in the return fuel with engine running.
Great idea. I like breaking things down into component parts for isolation also. I have a primer pump which was actually from a Detroit powered genset I use in the shop I could push fuel right into the primary filter and return from the head with a bucket in the middle. This would eliminate the tractor's fuel tank altogether. If it ran alright then I could plumb it into the suction side of the pump and ascertain if the problem returns as the little gear pump would then be back in the equation. My manual primer pump is a flow through type and meant to be in the fuel supply line always.
Not 100% sure of how this primer pump is designed but I would be wondering if there are some seals that could be leaking on it causing a problem.
I did not get over to the tractor today. Rather spent some time rebuilding a couple of carburetors, and freeing up an engine that had stuck over the past few months. Boy was I pissed at myself over that one. Also started a Mack diesel chassis that hasn't ran since 2014 on Christmas day. Primed it up, a 12V battery on the ground and it rolled right to life. Have a couple of deliveries tomorrow morning and then should be able to get after it as another warm day on tap. I did find a pair of gauges to plumb in and once mounted, they will stay there most likely. Still need to round up a clean bucket for fuel to watch for bubbles.
It's very possible the primer pump is worn out. I don't know if there are replaceable seals or not in this gear pump, but usually when they go it's best to get a reman from the DDA dealer if still possible. Personally I've not had good luck with Interstate-Mcbee parts lasting, so always went with "Reliabilt" from Detroit Diesel. I should have a new phone this afternoon after being victimized by the postal service yet again. They lost the original purchase so the vendor shipped another new one and it should arrive today. Found a new bucket to use for fuel supply testing and what doesn't get used will just go into the tank afterward. Pretty soupy around here now so hopefully I can get to work with this later today.
How did you clean the carburetors? I rebuilt alot of them in the past but with ethanol fuel being used now i cant seen to get them cleaned out.
I mix my own carburetor soak which is methylene chloride based and works well. Same solution I use for paint spay guns during overhaul.
Transfer pump is bad. Only about 12psi developed steadily and upon power application the output is not steady at all shown with a fluctuating needle indication. Finally have all four gears in the transmission operational. There is a "gimble" joint in the shifter base and it reverses the shift pattern from automotive use. I mean low gear is to the right and down. High gear is up and to the left. It is a four speed Borg-Warner T18 series commonly used in Ford pickups. There is no reverse gear available in the transmission although it may just be blocked out. The shift rail was frozen solid from lack of use, but after getting the transmission up to operating temperature, and a little force, it popped free. All four gears now work and first gear is very low just as in a 3/4 ton truck of days gone by. I have the engine model number and will get a reman pump coming along shortly. I will then test again. Shuttle transmission engagement continues to improve meaning more aggressive with lessening slip. I'm going to get a few hours on it and then change the oil and again add the Lucas Transmission Fix supplement as it does seem to work. Will need to rebuild the orbital steering valve as it seems to bind a bit; sometimes easy to steer, sometimes effort is needed. No ideas there yet.
How much vacuum is the pump pulling at what RPM. Check the return fitting on the head for a .070 " restriction. The pump pressures and vacuum are at 2000rpm and above no load. Bob
I will attempt to check that tomorrow. Worked longer today than expected.
Pulled off the discharge hose at the fitting and it looks to be a restrictor fitting but I didn't have a round feeler gauge large enough to measure exactly. For the short period of time the engine will fully rev before cutting out and against the governor, I only get about 15-17psi but that's only for about three seconds before the engine starts bucking. I've rounded up an electric pump but need a pressure regulator to apply a specific pressure to the head gallery for further isolation. I did not take an inches of mercury measurement as didn't have enough fittings with me. Both fuel lines, (supply, and return) to/from tank are replacements and blow through freely by mouth. I can only get a partial of the fuel pump casting number which is 517728X. I cannot read the last number. There is nothing stamped onto the face where the hoses attach that I can see. I didn't have a mirror with me but I did clean the dirt and paint from this face and nothing I could see for identifications stampings.
Plumbed in a new glycerin dampened gauge at the head and only about 7psi was achieved. Suction on the pump was negligible as the resolution on my gauge is not that good but save to say one, to two inches is all. A reman pump has been ordered and I'll see it yet this week hopefully.
If you have a minute pull the hex plug on the pump and check the relief valve and spring. Bob
Hi and thank you. I did check those parts. The valve was free and not frozen with good spring tension against it.
New pump showed up today and it's a left hand rotation where I need a right hand pump. This was packaged incorrectly as the label clearly states "Right Hand" rotation. Located a rebuilt pump on ebay with the exact same part number and the gent shipped it today. This pump is a "Reliabilt" unit and never installed. I'll drop the incorrect pump back in the mail tomorrow morning.
You mentioned that some of the fuel lines have been replaced. Make sure the lines from the gear pump to the secondary filter are rated to hold the pump pressure. They were usually steel from new. I found one which had a rubber carburetor low pressure rated fuel line instead that collapsed on the inside. I have also seen the low pressure primary filters used in the secondary filter canister and they fail plugging the line to the head with little fuel and pressure allowed through. Sounds like you got it figured out, but wanted to share a couple quite common issues we found in the past.
Hi and thanks. The suction line from the tank to the inlet of the first fuel filter is low pressure carburetor fuel hose. From this filter canister to the inlet of the gear pump is a hydraulic hose with crimped ends. From the discharge side of gear pump to the inlet of the second filter is another hydraulic hose with crimped ends. From this second filter cannister to the head inlet is yet another hydraulic hose with crimped ends. The return to tank from the restrictor fitting is a low pressure fuel line. I don't know what SAE hose it is but I've had it all off the engine and blown through it, (by mouth) and really didn't note any undue restriction. When I replaced both filter elements I verified they were correct in the housings. They are WIX filters from Napa and all the gaskets/seal rings were replaced also. When I had the original pump removed I pulled the hex plug in the side, removed the spring, and when I turned the pump sideways, the relieve valve slipped out in my hand without a hesitation. I looked and seen nothing on either the valve, or seat which would cause constant pressure relief, or bypass. I didn't take the body apart but I did dunk it in the solvent tank, (mineral spirits) and gave it a good douche and degreasing and when clean nothing looks out of sorts. I then put it back together and remounted onto the engine with the same results. The replacement pump is currently in St. Louis so should have it tomorrow and will get it installed and checked out shortly thereafter. Really appreciate the help/guidance/ideas as it helps keep me motivated to work on this old crap. Besides being a lot of fun, it does a good job keeping me out of jail. Thanks,
New pump took care of the problem. I built up and replaced the low pressure hose on the discharge side of the restriction fitting and installed a small hydraulic needle valve and gauge into this line for testing purposes. This is the hose returning to tank. The original pump would not build hardly any pressure at all remaining under 10psi with the needle valve completely closed just before engine stall. The new pump in the same scenario unloads at about 85-90psi and the engine stalls shortly thereafter. Normal operation pressure at about 1500 or so rpm, (no tachometer installed) is about 40psi with a gauge plumbed permanent. The engine miss or high speed "flutter" is gone, and she screams as should.
So that's the sound that woke me up!