I've got a 98 Komatsu with a Impco Model J regulator vaporizer converter. Purchased the lift recently with the conversion to LPG.
So the regulator freezes up fairly quickly (within 5 minutes). The hoses don't feel warm, so I pulled both the inlet and outlet radiator lines off the regulator and when the lift is running, I'm seeing no radiator fluid being pumped into the regulator.
I do know that a radiator leak additive was added to the system. I certainly top off the radiator with fluid.
I'm not sure what I need to do next in order to check for a blockage in the system & get coolant running to the regulator?
Showing items 1 - 13 of 13 results.
Good info to know. You wouldn't normally expect that.
Recently had this problem on a Cat truck with a Mitsi v6. It had no thermostat. When the truck idled, there was no flow to the regulator. It would freeze up while idling in the yard. With no thermostat, the coolant will flow through the path of least resistance. It this case, it was the radiator. A new thermostat fixed the problem
Ahhhhhh the old stop leak fix! I have repaired and replaced more regulators because of stop leak than Carter has liver pills. If the regulator has a brass tube approximately 3 inches long and designates a flow direction, it is a thermostat for the regulator. The kinked hose is not helping either. The stop leak will clog up the regulator thermostat. These units are designed to run with engine thermostat and would be really impressed if unit does not run hot without one. As mentioned above, flush system, clean coolant piping to regulator and fix the kink. If after these suggestions and unit still freezes, we will have to look into possible bad regulator but it running tells me it has to do with regulator coolant flow.
gotta love these machines that havn't been maintained very well...
nice and gunky... ugggh
anyways from those pics i see that first pic of the housing up near the top on the side that has the sensor beside it appears to be the thermostat housing. My guess is if there was no thermostat in it, that someone has removed it at some point in the past. If that flange has a machined out groove like most theromstat housings do this is where the thermostat would normally seat when in place.
The hose that runs from under that housing down to the side of the engine block beside the waterpump? It looks to be someone put a regular (non-molded) hose there, hence the reason for the kink in it, it doesn't look normal to me. I'll also assume that hose running to the LP regular taps into the side of the housing where the theromstat is? That would be the bypass circuit i mentioned earlier. It should run to one side of the regulator and then out the other side and tap back into the system at another point probably around the intake manifold?
I would make sure that bypass circuit is clear.
From the looks of the pic's though the inside of it looks fairly clean.
Before you took this apart did you run the truck and check for circulation?
Here's what is see from the pics. TB42 motor. The aluminum piece you took off is the thermostat housing and is missing the thermostat. That must be in there to allow proper water flow to the LP regulator. The exhaust manifold is no way connected to that thermostat housing. I think if you check the hoses for blockage and fix the kinks and put a thermostat in it, that should fix it.
Yep, I was thinking it was a Nissan H-20 II engine but the pictures tell the truth.
OK, game changer here. You must have an 8000#capacity machine? Cause that looks like a Nissan TB42 engine. Pictures sure help! Sorry, I'm not very familiar with that engine.
I posted a link to photobucket pictures.
Ok, so I removed the entire seat & assembly for pretty easy access to the front of the engine / rear of the lift.
I removed the aluminum cast hose inlet. I was assuming this is the thermostat housing but there was no thermostat? Is this correct?
Not sure who worked on my lift prior but I'm getting the feeling he/she was a seriously shady "mechanic".
It is hard to see for sure due to all the engine grease build-up but the aluminum hose "inlet" for the upper radiator hose appears to be a part of the cast exhaust manifold?
The smaller diameter (maybe 1" OD) lower hose which is plumbed to the water pump has a kink in it which may be preventing water flow. I don't think this is a OEM hose with the proper radius or bent.
The other hose which is plumbed under the length of the exhaust manifold and connects to the LPG regulator is very difficult to access. I want to remove this hose to look inside. Does anyone know if I need to remove the entire manifold to dig one layer deeper?
Pictures located here:
s1270.photobucket.com/user/dcg4403/library/1998%20Komatsu%20FG35ST-6
Thanks for the all the recommendations. I'm going to do exactly as Swoop223 suggests.
Question for you as I haven't worked on a forklift before but have rebuilt plenty of motors in my life. Is there any way to gain easier access to the front of the motor? The left side exhaust manifold covers the junction of the water coolant hoses near the water pump. So I can barely get my hand in there, let alone see anything.
Appears I need to pull the manifold but was hoping maybe I'm not seeing something that can be removed at the rear end of the lift & provide full access to the front of the motor (water pump = front motor).
All LP regulators use the cooling system bypass circuit to provide coolant to the regulator. As was suggested, remove the hoses supplying coolant to the regulator and check them for blockage.
Even check the fittings where the hoses connect at the engine block and make sure they are not blocked off with gunk.
I have even had the intake get clogged with silicates on engines before and will prevent the bypass from circulating coolant so i would not leave any possibility unchecked.
Drain all the coolant from the system and check every hose and fitting, use air to blow through the hoses and engine block to make sure all path's are clear.
The coolant hoses have to be routed properly to have flow.
One hose comes off the front of the cylinder head and the other hose connects to the water pump housing below where the lower radiator hose connects to the thermostat casting.
If the coolant hoses serving the J-model are connected any other way I would be suspicious of flow.
Interesting. It could also be a blockage as well. That should be the old H20 Nissan. I don't think it would hurt to remove radiator cap and blow air back into each coolant hose. Gravity should take care of the rest.
Sounds like a bad water pump and/or thermostat. The water pump on that lift is super easy to change out and pretty cheap.
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