I had a coolant flush today at a local mechanic shop and when i got back home and read the receipt (i should have done that at the shop but i was distracted from my kid) i realized that the mechanic only put two gallons of the PEAK OAT Pink stuff that is already 50/50. which means he filled the rest with water. Even my reservoir looks like it is straight water barely any pink in it. Should i be concerned ? or is it okay ?
I definitely plan on going back tmrw because it does not sound right (there is a reason the 50/50 has a big sign saying DO NOT ADD WATER) right ???

 

2 gallons sounds about right when flushing out coolant, that's all it should take, even on a flush you will not get everything out, so 2 gallons is good

 

RAVE says 12L to refill the V8 cooling system. That's a little over 3 gallons.

 

Some coolant always stays in the block.

You've got some flexibility depending on your regions climate as well. Where I'm at I usually do 1 gal/antifreeze and 1.5 to 2 gal/water.

There are antifreezes though that do not take water. I doubt that pink stuff is among them, but I don't know enough about it to say for sure that it's not. Also generally not recommended to mix different types of antifreeze, ie. The pink with whatever was still left in the block. Probably dexcool, maybe green. I run green in pretty much everything. That said, since it lists 98 and up Disco on the front, I'd say it's probably ok to mix with dexcool even if it's not optimal.

 

Would the block really retain about 1/3 of the capacity of the entire cooling system? Seems unlikely that it would be that much.

 

yes everytime i did a coolant change usually 2 jugs is enough

 

About 1 gallon stays in the block. I measured into a dry system, then draining out of the radiator. It makes sense if you think about the size of the block and coolant jacket volumes. Works out great if you use concentrated glycol vs pre-mixed.