Good Morning. My old D5 dozer (96J) is overheating fairly quickly and has low power under load, even climbing up an incline. Changed all the fuel filters and cleaned the lines, also removed and cleaned the injectors, but still have the issue. I'm pretty sure the overheating is just a symptom of the low power since the thermostat is working, the radiator is clean, new belts, and the fluid level is good. The machine runs fine both at idle and under full throttle when not under a load - no misses, but it might not be topping out quite as high as it used too...hard to tell by just sound. Based on all that, I'm thinking my problem is with my injection pump. Does that sound right? Also, can I rebuild the pump myself by just replacing the plunger and barrel assemblies along with gaskets and o-rings or are there adjustments that need to be made by a shop to get the pressures correct? If needed, the engine arrangement is a 2P6789.
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D5 96J Overheating and Low Power
- Thread starter RossEagar
- Start date
No, if you're asking the question, then you can't rebuild the injection pump yourself.
What does the exhaust smoke look like? when it's running high idle? and when it's under full load, like trying to climb an incline where you really feel the low power?
What does it do when it overheats? blow coolant all over? get up to the upper end of the green? Can you take it's temperature with a temp gun when it's overheated as hot as you get it? like the inlet from the radiator, the outlet to the radiator, and a few places on the block and head.
What does the exhaust smoke look like? when it's running high idle? and when it's under full load, like trying to climb an incline where you really feel the low power?
What does it do when it overheats? blow coolant all over? get up to the upper end of the green? Can you take it's temperature with a temp gun when it's overheated as hot as you get it? like the inlet from the radiator, the outlet to the radiator, and a few places on the block and head.
The first time it overheated, it got up into the red before I noticed it and blew coolant out. Since then, as I've tried things, I keep a close eye on the temp gauge and shut it down when it gets up near red. I did heat up the thermostat in a pot of water on the stove and it opened at 175 like it should. By the way, the temp gauge and sensor are new as well so I'm fairly confident the temp is reading right.
I took the pump out last night so I can't run it right now, but I don't remember seeing a lot of difference in the exhaust. Maybe just a little gray smoke, but nothing that really jumped out at me like white smoke (i.e. head gasket), but that was a thought as well.
Regarding the pump, I've rebuilt a couple of Dav pumps on tractors I've got and, honestly, this one looks simpler than those from the diagrams I see, but the devils in the details. It looks like I'd need a special tool to remove the plungers (8T5287?). I just hate to pay $1800+ for someone to put a kit in that I can do myself. For that price, I can replace all the plungers and barrels along with a new shaft. To provide a little background, I've had the machine about 10 years and have done all the work on it myself including full engine and transmission rebuilds along with repairs of both final drives. The injection pump is literally the only thing I haven't been into on it.
I took the pump out last night so I can't run it right now, but I don't remember seeing a lot of difference in the exhaust. Maybe just a little gray smoke, but nothing that really jumped out at me like white smoke (i.e. head gasket), but that was a thought as well.
Regarding the pump, I've rebuilt a couple of Dav pumps on tractors I've got and, honestly, this one looks simpler than those from the diagrams I see, but the devils in the details. It looks like I'd need a special tool to remove the plungers (8T5287?). I just hate to pay $1800+ for someone to put a kit in that I can do myself. For that price, I can replace all the plungers and barrels along with a new shaft. To provide a little background, I've had the machine about 10 years and have done all the work on it myself including full engine and transmission rebuilds along with repairs of both final drives. The injection pump is literally the only thing I haven't been into on it.
Tugger2
Senior Member
Mechanics i know have always sent the pumps out to the fuel shop , they know thier stuff to.
sled dog
Senior Member
A plugged or mostly plugged transmission cooler will raise that temp rapidly
you can lap the plungers if it is running or replace ,just get back in rack right, and was the water pump in tack have had 3306 impeler to come loose last time i put plungers cost about 700 i have laped and had good luck if it is runing i would check rad the last one i had was d5b getting hot blew rad out went to leaking best thing to happen put new core fixed problem if the old ones run hot some thing is wrong
Mark250
Senior Member
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- Aug 30, 2015
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- heavy equipment technician
have you checked the torque convertor temp as a possible input to your over heating problem
It's not the torque converter. I've had that problem in the past and know how it will heat up the engine if you're not getting enough oil through there. I've got a separate TC gauge and it doesn't even get up to normal before the engine is overheating. When I had the thermostat out, I turned it over and the water pump seemed to be working but I didn't really have a way to check the flow. I'll get out tomorrow and check on it a little more. As you mention, Dozr, I'll check into the plungers. To me, it just seems to be a fuel issue due to the lack of power.
Bls repair
Senior Member
Air filter clogged ?
@Delmer, I completely understand where you're coming from. I've had a lot of the same thoughts. I realize it's a stretch on the fuel pump causing the overheating. My thought was if it wasn't getting enough fuel, it would cause the engine to work harder when under load and heat up quicker. After your first reply, I was thinking something like a blown head gasket could be the culprit. I wasn't seeing any excess blow-by from the engine or signs of exhaust in the coolant, but the loss of power and heating up sure points in that direction. Given that, I pulled the head and replaced the gasket with an official Cat over the weekend. Cylinder walls were all good, but I did have a little pitting in a couple of the pistons. If I remember right, though, that's not new. Took it for a test drive after I got everything back together and no change. Still heats up and low power. I guess it's possible I've got a cracked head, but I would expect to see either blow-by or more problems with the coolant. I can run it wide open just sitting with the radiator cap off and watch the water flow through the radiator. No bubbling or signs of exhaust. I'll double check the air filter later today. I replaced it not many hours ago so I'd surprised if it was clogged.
When trying to diagnose an overheating issue, a very good place to start is by checking the temperature of the coolant going into and out of the radiator with a temp gun (cheap at harborfright, or a good used one on ebay).
Removing the head and injection pump would need some pretty solid evidence for me to attempt.
Removing the head and injection pump would need some pretty solid evidence for me to attempt.
Nige
Senior Member
+1 on Delmer's idea.
Get hold of a non-contact thermometer and shoot the temperature of the main radiator hoses upper and lower. You should be looking at a temperature differential of around 18 degrees Fahrenheit between the top & bottom if the radiator is in good condition.
Get hold of a non-contact thermometer and shoot the temperature of the main radiator hoses upper and lower. You should be looking at a temperature differential of around 18 degrees Fahrenheit between the top & bottom if the radiator is in good condition.
Old Magnet
Senior Member
Here's some guidelines on temperature checks.....
Fairly common to have pulley sheave wear allowing fan belt slippage
Fairly common to have pulley sheave wear allowing fan belt slippage
1466IH
Senior Member
I'm not saying that your pump is the problem but on older high houred machines I have seen new nozzles make an old pump run worse. IMHO you are better off to do the pump/sticks together. When you rebuild nozzles and they are opening at the proper spec it makes your old worn pump have to work that much harder to open them