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2500 Coolant Change and New Owner Issues

Thor Hammer

Full Member
Joined
Jun 29, 2020
Messages
60
About to change my water pump on the 8.1. I found that the coolant capacity is around 7 gallons of DexCool. My question is if any of you that have changed out your water pump how much coolant did you actually need on re-fill? I really dont want to spend $100 dollars on coolant!

Bought this beautiful black truck with 97K on July 9th and have sadly driven it twice.

  • Transfercase was shot (oil loss due to pump rub. Rebuilt a donor case with all new clutches, bearings, chain, etc. Installed and working great!)
  • Yoke on rear driveline had a nice deep groove in it. Replaced along with spicer u-joints. Balanced professionally.
  • Spark plug wires stuck on plugs. Destroyed plug boot trying to one off. Now i have a misfire. Ha! (probably stock, replacing all of the plugs and wires tonight)
  • Water pump leaks from weep hole. New one going in Saturday along with 180F high flow Motorad t-stat, new idler pulleys, and belts.
  • Previous owner cut the wheel studs off flush with the 1.5" spacers to get that "BRO" stance. FML. So need to press in new studs or replace both front hub assemblies.
  • Have a 3A parasitic drain on the battery. Could be wiring on seats. Read this has been the issue for others. I'm an electrical engineer so that helps!
  • Code for oil pressure circuit. Need to change out sensor on back of motor. Hard to get to? Any advice?
  • Previous owner cut off bump stops. Seriously?! Hahaha! Why? Just why?
  • Driver seat electric controls broken. Replaced with used one off of Ebay.
  • Picked up a set of Raybestos performance pads and AC Delco slotted rotors. Need to solve wheel stud issue first. As I have a set of 17X9 Hardrock simulated bead lock wheels to install along with 33X12.5X17 Nitto Ridge Grapplers. Right now the guy I got it from put on stock 2018 dodge ram 2500 aluminum wheels and Firestone 33.2" Transforce tires. Dodge on Chevy? No way!

So as you can see the list is long and its been a hard road. I hope to have all the issues sorted in the next couple of weeks.

With the 33's (actual diameter is 32.7") I'll be re-gearing to 4:56 (3:73 right now) and installing a Detroit Locker in the 14 bolt. I'd also like to put on at least a 3-4" suspension lift but sadly only lifts available are knuckle lifts. BDS makes a coilover conversion kit for the front but its $6000! Uh, no.

Any advice or tips greatly appreciated. Goal is to turn this beast into a backcountry exploring overland rig.
 
I've got the 5.3L not the 8.1, but I lost 3 gallons out of the 4.2(?) initial fill capacity when changing the water pump. Maybe you'll have a similar ratio of loss.
 
I've got the 5.3L not the 8.1, but I lost 3 gallons out of the 4.2(?) initial fill capacity when changing the water pump. Maybe you'll have a similar ratio of loss.

Thanks for the reply. Perhaps I'll just pick up 4 gallons and see where I'm at. parts store is close by in case I need more.
 
2500/8.1L coolant capacity is 20.7 quarts, a little over 5 gallons. When I flushed/changed the coolant at about 100,000 put back 5 plus gallons. When I replaced the water pump and radiator at 196,000 I put back about the same, a little over 5 gallons.

Also if you switch to a 180 deg t-stat you should retune for it or it will not come out of closed loop until it reaches 196 deg. Not a problem in the summer months as the temp will get up there, but in the winter the 180 stat will open and keep the temp from reaching the set point in the computer.

And yes the oil pressure sender is tuff to get to it can be done with a lot of cursing.. Advice is a friend with small hands, or pull the valve cover which will make it a lot easier.


Got to keep the 2500's on the road.. They are a rare AV...
 
I ended up removing the left side valve cover so I could get my hand back there, then with the help of my inspection camera I guided the 27mm impact socket on the sensor. The other hard part is getting the new one started in thread. So I cut a piece of hose and inserted the new sensor in it and feed it down used my other hand to get it started. Now half my body was on top of the motor, so you are going to get up close and personal with the motor.

Good Luck

See if this helps

 
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You don't have to replace the fluid just collect it and reuse it, put a painter's filter over the fill and reuse, then top off.
 
2500/8.1L coolant capacity is 20.7 quarts, a little over 5 gallons. When I flushed/changed the coolant at about 100,000 put back 5 plus gallons. When I replaced the water pump and radiator at 196,000 I put back about the same, a little over 5 gallons.

Also if you switch to a 180 deg t-stat you should retune for it or it will not come out of closed loop until it reaches 196 deg. Not a problem in the summer months as the temp will get up there, but in the winter the 180 stat will open and keep the temp from reaching the set point in the computer.

And yes the oil pressure sender is tuff to get to it can be done with a lot of cursing.. Advice is a friend with small hands, or pull the valve cover which will make it a lot easier.


Got to keep the 2500's on the road.. They are a rare AV...

Well I got the water pump changed out and only needed exactly 3 gallons of coolant. Wasnt too bad of a job. Would have been easier with a proper spanner/fan pulley tool. My spanner wrench for adjusting the coilovers on my mazdaspeed worked just good enough. That and an oversized crescent beat on with my 10lb sledge to get the fan free from the pump.

I didn't know that about the 180 tstat. Whom can I contact for a tune? Any suggestions? She definitely runs cooler than before!

I have little doubt those spark plugs I pulled were from 2003. The electrodes were dark brown, burnt down and the gap was at least 1/8"! I gapped the new NGK's to 0.045" and it runs beautifully.
 
I ended up removing the left side valve cover so I could get my hand back there, then with the help of my inspection camera I guided the 27mm impact socket on the sensor. The other hard part is getting the new one started in thread. So I cut a piece of hose and inserted the new sensor in it and feed it down used my other hand to get it started. Now half my body was on top of the motor, so you are going to get up close and personal with the motor.

Good Luck

See if this helps


I saw that mentioned in a few youtube videos. I just may do that. Seems easy enough. I've gotten very good at threading things into blind holes having owned a 2007 Mazdaspeed 6 the past 5 years.
 
I spoke with Brazels RV performance and Blackbear performance. Neither tuner indicated a need to tune for the 180 Tstat. Regardless, I plan on tuning with Blackbear once I get my hands on some Raylar cams, roller rockers, and port the intake.

Are the aftermarket intakes like Volant worth the investment? I've heard mixed reviews.
 
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