M1009 Planned Maintenance

[cmroles]

I have small (slow drip) coolant leak coming from somewhere under my radiator on the drivers side. I also have some seepage from my oil cooler lines (looks like from where the fittings are crimped onto the rubber part of the hose)

Since I will need to pull the radiator I was planning on tearing into some other things while I'm at it.

What I'd like to replace:

Oil Cooler Lines
Thermostat
Upper / Lower Radiator Hoses
Heater Hoses

Since I'm going to be that far into it I was also thinking of replacing the water pump and harmonic dampener. These are more for preventive purposes since I don't think I've had issues with either. Is there a test of some sort that will determine if these need replacement, or should it just be done for peace of mind?

Other than this, am I missing anything that should be replaced? I hate the thought of getting stranded because I forgot to check / replace something minor...

 

[OL AG '89]

It's a twenty five (plus) year old vehicle.....
There are too many things to list.
Have you done a PMCS per the -10, -20?
Do those and that's a good starting place.
The water pump is a comfort thing.... If it's not weeping, then it's good.
The harmonic balancer is really a good idea, but again a comfort item.
There is a section in the TM as well, not sure if there is a test for it.

I just discovered a leaking injector at last inspection, so my next task is going to be the injector replacement..... A leaking injector could cause a catastrophic failure/fire if it failed while engine is running.

 

[K9Vic]

Inspect you harmonic balance for wobble, if there is some then replace it. If it is stable then it is likely fine. I have replaced them before and it is not difficult process and can be done with out removing the radiator. However, if you are taking the radiator out then I would replace the balancer if it was me. Only because the age of the truck and you already have the parts out needed to replace it.

If the water pump has no problems, then I would not replace it. The pump you have in there now is likely an original USA made GM part and not a Chinese replacement. You may find yourself getting a bad pump and have to go through the whole process again. I would just leave it alone unless you see any leaks or issues that you have to replace it.

If you are replacing one hose, replace them all in the coolant system. I had a lower radiator hose start to leak on me Friday. I replaced all hoses at the same time just because I had to drain the system. That is a good peace of mind cost as being used you do not know how old the others are and when they might break. Plus says some money on antifreeze only replacing it once.

 

[cmroles]

I just discovered a leaking injector at last inspection, so my next task is going to be the injector replacement..... A leaking injector could cause a catastrophic failure/fire if it failed while engine is running.

I fixed one of those already...

Turned out to be a pinhole in the return line hose. I was testing GP's and found one that was totally drenched in Diesel. It had a steady drip from that line that had leaked all over the GP, head, frame rail, etc.

Thankfully it was close enough to just cut off 1/2" of hose and reinstall with a new clamp - leak stopped.