Engine/Transmission (1998.5 - 2002) Coolant replacement/flush questions

[RDMueller]

I'm getting ready to replace the coolant on my truck and this will be the first time I've done it myself. It seems like it should be pretty straight forward, but there are a few details I'm wondering about.



When I've done this in the past on other vehicles, I remember that the block holds a significant amount of water that you can't drain. Therefore, if you are flushing with tap water, you will be left with some amount of tap water in the system after you fill with coolant and distilled water. I always thought tap water in the system was a no no. On the Cummins, does opening the drain on the radiator allow most or all of the coolant to drain? If not, what is the recommended procedure to ensure you end up with a 50/50 mix of coolant and distilled water, and no tap water in the system?



One other thing, truck is an 01. 5 with 230K miles and since I'm the 2nd owner, I have no idea if the water pump has ever been replaced. Is there a recommended replacement interval?



Thanks for the input!

 

[georgej]

Some will remove the bottom hose to more completely drain the coolant and some will run the rear tires up on ramps to accomplish the same. I usually use some ramps and drain what I can, then put new antifreeze/distilled water back in. I change every two years and the truck is ten years old with the original heater core and a no cooling issues when towing.

You can check under the water pump pulley (on the WP housing itself) to see if there is coolant leaking from a weep hole. If so replace. I carry a spare now since it's a pretty easy replacement item and you don't lose a lot of coolant. One other thing, before opening the petcock go to the dealer and buy a new O-ring. Sometimes they will tear when twisting and pulling that petcock open. Use a little faucet grease(clear silicon grease) when you re-install.

 

[Diesel Gunner]

Consider this. Put new serpentine belt, hoses, water pump, and thermostat on while you have the radiator out to clean all of the oily residue that is on the rear of it. These parts go in your boonie box and will be helpful in the event of a breakdown on the road to at least get you home. With the rear wheels high what I do is flush with distilled water from a 5 gallon and then blow through block with compressed air (while all o9f the system is off and open) and this will get as much as possible out of the block.



Reassemble and refill. I do not enjoy this so on my last service I refilled with Delo ELC. My engine vent is routed down below the axle and doesn't seem to goo up the back of the radiator so my hope is that I will be in better shape for a longer period of time.

 

[Tinman]

I recently replaced all my hoses since I had to replace the heater core. (I did the pressure wash of the crap from the CCV a few years ago. ) Yes, tap water is a no-no. What I did was remove the thermostat, and fill and flush with distilled water until basically clear water came out of the petcock. "Flushing" is done by cranking and letting the water mix, which is greatly reduced in time without the thermostat. (You'd have to wait until operating temp and the the thermostat to open if it is left in. ) The thermostat housing will leak a little without the actually thermostat in it, but it does matter b/o you only run it a few minutes to circulate the water. This took 7-8 cycles and about 20+ gallons of distilled water. I was switching to polyethlyene so I wanted as much out as possible. On level ground there is about 2 gallons left in the block after draining. You'll have to use 100% coolant (not 50/50) for at least those 2 gallons. It a little tedious, but it doesn't have to be done but once in a blue moon.

 

[BDahm]

Did the same thing not too long ago, like they said lower hose off and raise the back. Use an ELC like Fleetgaurd ES Complet and compensate for the water you used to flush in the block when mixing new coolant. Otherwise you guys pretty much said it all

 

[RDMueller]

Thanks everyone for all the good advice! Next nice day I'll take care of this as well as some other items I've been wanting to address for a while.

 

[GOTSOOT]

someone needs to get an old block and experiment on the lower pass. side near the pan rail, and drill and tap a drain hole that will empty the block completely. !!

 

[RDMueller]

someone needs to get an old block and experiment on the lower pass. side near the pan rail, and drill and tap a drain hole that will empty the block completely. !!

Makes you wonder why none of the manufacturers install such a drain hole... Also, I wonder what the dealer does when you take a vehicle in for a coolant flush. My bet is that some tap water gets left in the system. At best, maybe they have some kind of filter arrangement that filters the tap water before going into your engine.

 

[WestTN]

The low spot in the Cummins we all know and love is the water pump. When you drain it, on level ground, it WILL be completely drained. The water pump is sealed with an o-ring, so you can drain it, then replace the pump and most likely have no leak.

 

[RDMueller]

The low spot in the Cummins we all know and love is the water pump. When you drain it, on level ground, it WILL be completely drained. The water pump is sealed with an o-ring, so you can drain it, then replace the pump and most likely have no leak.

Didn't realize that. Good news since I was planning on replacing the water pump anyway as preventative maintenance.

 

[ChrisOlson]

this is a great thread thanks for all the tips I have been working towards cleaning my cooling system as well.

thanks

Chris

 

[ChrisOlson]

Makes you wonder why none of the manufacturers install such a drain hole... Also, I wonder what the dealer does when you take a vehicle in for a coolant flush. My bet is that some tap water gets left in the system. At best, maybe they have some kind of filter arrangement that filters the tap water before going into your engine.

I took my truck in for a coolant flush in MT at a Quick lube Place.

they hooked their Machine up to it and I could not get the truck hot enough for the T stat to open spent a hour fiddle fartin around with it I refused to pay for the service.



Chris

 

[Tinman]

I took my truck in for a coolant flush in MT at a Quick lube Place.

they hooked their Machine up to it and I could not get the truck hot enough for the T stat to open spent a hour fiddle fartin around with it I refused to pay for the service.



Chris

Only way to do something right is do it yourself.

 

[Tinman]

The low spot in the Cummins we all know and love is the water pump. When you drain it, on level ground, it WILL be completely drained. The water pump is sealed with an o-ring, so you can drain it, then replace the pump and most likely have no leak.

I thought to water pump was above the idler pulley? No where the low point.