I have checked PRV solenoid seem to be ok. idle is rough but smooths out at higher rpm. have checked speed sensor screen.
Sounds like one pump not destroying, putting out to much volume, going to need to check pressures at pumps, do u have service manual and any gauges?
Thanks overworked, for responding. the machine is in Africa. I am in Dallas. but I will be going to the machine next week. I wanted to get any parts to bring with me because availability is an issue. The pressures are 460 pilot and main is around 4600. the pump has been rebuilt and set to spec buy the Cat specialist about 40 hrs ago. The staling under load appeared 1st ,the machine sat for about 1 month because of extreme rain. now my operator went to start up the machine and the left track was slower. we have gauges and a service manual. Is there anyone on this thread who wants a free trip to Africa and a handsome salary for a weeks work.
Does the engine stall with one pump or two, if one, is it the left or right pump? When it stalls, does it smoke? how is boost pressure? does it recover if let go of joysticks? You say main was 4600, which pump was that? both? main should be 4950 ± 72 psi. Is the monitor on boom priority, top left button. Does it miss track at both hi an low speed, forward and reverse?
he will check later to day on which pump is stalling. when it stalls it doesn't smoke. I am not a tech so I don't know what boost pressure is. it does recover if you release the sticks. the main does not go higher than 4600.is Does the main relief need to be adjusted.yes it is on boom priority. it misses hi and low but he seemed to think reverse was worse.
the engine had its 10,000 hr rebuild about 50 hrs ago new crank piston sleeves, the full meal deal. also brand new turbo.
it is a 330bl 6dr2055
I think you should look at engine performance since you get no smoke when it stalls, blow out all fuel suction lines and clean the screen and replace filter.
The fuel system might use a new governor spring and flip the thrust washers for the flyweights. Then adjust the setpoint. Once that is done callibrate the throttle control. These things should accompany a rebuild at those hours. Later Bob
Is the governor is that box that the throttle cable attaches to contol throttle? If so is is brand new. also the plungers and injectors are new cat pars and the diesel pump has been rebuilt . It was not doing this after the rebuild. I am not a diesel tech but I am mechanically inclined.I used to work on the line rebuild in engines at the VW dealership. could you go into more detail about the thrust washers for the flyweights ? Is the set point on the governor? how could this problem make it track slow on the lft side? fuel filters are new and screens are clean. what would cause the main pump pressure to be 4600 psi rather than the 4950 psi.
These could be the same problem or could be two totally different problems. The throttle control was replaced, but was it calibrated? This is done through the monitor panel. What is high idle?
If the governor and fuel pump was reconditioned(gov is on the back of the pump) then the throttle control needs to be callibrated as Lee just said. The setpoint should have been adjusted on the test bench. Now for the LH drive slow I think the slow return check valve may be giving you trouble. Follow the big line from the top of the swing motor to the aluminium block near the cooler. There are two big check valves inside it. The Slow Return Check Valve that holds a back pressure on the return to tank oil to prevent the swing motor from cavitating when coasting to a stop. The other check valve is the Cooler Bypass Valve. It allows cold oil to bypass the cooler rather than dammage it from overpressure. Either of these check valves can back out and not open enough to operate correctly. Later Bob
The big give away for the slow return check that came apart is in the boom circuit. At a lower idle, lift the boom. if it pauses and then jerks up i bet the slow return check is bad. a slow track in one direction sounds like the crossover line relief, easy to check by swapping top to bottom.
the boom does not hesitate it is just slow. everything is slow, swinging , tracking the left is just slower. would the slow return check being bad cause everything to be slow?
It depends how far it has backed out, It can cause slow operation to very slow jerkey operation. It restricts return flow to cooler and tank. This causes the NFC pressure to be unable to drop and alow the pumps to open up to max for working. Later Bob
Thanks for you help. do you have a copy of the page from a manual so I can recognize which one it is? so that could be causing the 4600 psi main pressure? we are talking about the slow return?
I don't have a pic but get up on your machine, lift the hood and look for some large oil return lines joining at a big aluminium valve housing behind the top RH corner of the rad and cooler assem. One large line comes from valve, one from top of the swing motor and one goes to the cooler return to the filter housing. If this si causing lowmain pressure it's due to reduced pump output. Later Bob
could you give me the part number on the crossover line relief.
we've had afew of the 330C's hi speed piston wear out the housing inside the Hyd motor which causes the same thing, pretty easy to track (get it track) down the problem if it only tracks slow in high speed but it ok in low speed
changed the cooler bypass valve an slow line relase. it seemed to fix the problem at first. when the machine 1st started everything was as it should be. Both the upper and lower pumps did max out a 4950-5000 with full boom and stick this time. but when he hit the sticks it wanted to die and it could not make it up a 2% grade hill to park it. right side is definitely slower. on the crossover line relief did you mean the one on the travel motor behind the inside plate?
did it die both direction in and out with stick circuit
crossover line reliefs are in the motors behind the covers. If it is slow in one direction on one side only then it is likely the relief. Travel while curling the bucket and then travel while swinging. This will make it travel off one pump only and you can see how it responds. if it still miss tracks then it is not a pump problem. It will be slower but both side will be equally slow. What functions make the engine die?
the engine never dies there is no power. it will barley make it up a 2% grade. it seems to cycle properly at first start up from cold but, once it warms up it just creeps when you push the sticks and pedals. basically anything lifting boom ,bucket , stick travel, all make the rpm dive . no smoke though. The upper and lower pumps spike at 4950-5000 at the top of stick , bucket , boom all up.
I'm still maintaning my belief that if you have engine rpm loss on this machine and no visible smoke you have an engine not an hydraulic problem, these old bangers belch out black smoke if they are worked hard and get all the fuel they want.
I'm still maintaning my belief that if you have engine rpm loss on this machine and no visible smoke you have an engine not an hydraulic problem, these old bangers belch out black smoke if they are worked hard and get all the fuel they want, especially when fed the fuel avaliable in Africa...... Try to remove the fuel return line from the injection pump and put it in a bucket and measure how much it flows when engine is running at high idle, gives an indication if the fuel feed is ok.
I will do that tomorrow. how much flow should there be?
the flow is low on 10 speed it takes 4 min to fill a liter jug.
That's a bit low, are you sure all the fuel lines are free of obstructions and the filters and screen is clean? if you prime it with the handpump when it is shut off do you get flow then? If you pull the handle out, does it suck right back in when you let go? that's a tell tale sign that there's an obstruction somewhere on the suction side. You could have a bad check valve or broken spring in the transfer pump so it doesn't pump as it should..
Is there any banjo unions on the fuel lines that can bee clogged?
If the engine is being pulled down on its knees and there is no black smoke , the chances are great that its a fuel problem . You understand that when your speed controller is on ten you should be getting close to maximum operating rpm and maximum fuel flow. Now when the rpm starts coming back down towards idle because of load , you are still getting full fuel flow . Thats the reason why you should be seeing black smoke if hydraulics was the problem. No smoke under stall = fuel starve , my opinion .