Coolant capacity

[udidwht]

Looking at the following manual for the 1994 Chevy P30 manual I'm not seeing anywhere 'Coolant capacity'...

https://www.gmcmi.com/wp-content/uploads/2014/05/P30-Chassis-Manual.pdf


I'm getting ready to replace all the coolant hoses, Heater core hoses, T-stat and possibly the coolant temp switch (lower coroner of radiator) as well as the one near the T-stat.

I've in the annual the fluid capacity for oil, Trans and Differential fluid but nothing for Radiator/engine coolant capacity. Anyone know how much I should purchase? I'm thinking the capacity is in the ballpark of 20-25qts total.

This is for 7.4L 454 TBI w/4L80E (94 Fleetwood Southwind Storm 28ft)VIN#1GBJP37N4R3314754

Any other suggestions/tips before I dig into this would be great.

[udidwht]

Replaced both the upper & lower hoses as well as the by-pass hose and T-stat (195F).

The lower hose was stamp dated 01/14/94 and the upper was stamp dated 01/28/94. Their appearance looked not bad given the age. Still very pliable with no signs of cracking in or outside of the hose anywhere.

Anyhow adds apiece of mind that those won't be an issue to pop up at a horrible time (road trip).

No one was selling the GM by-pass hose tried several FLAPS incl. Chevy dealer who said it was a patented hose. They could order it but it would take 2 days to arrive. Went to NAPA and sourced a heater hose with a similar curve then trimmed it up for a perfect fit.

As for the amount of coolant drained after removing the lower hose. I had marked in (1) gallon increments (measured/marked prior) It was just over 3 gallons. Likely 13 quarts. Meaning that roughly 10 quarts remained.

I replaced what I removed with the Prestone 70/30 mix coolant. The previous time I did the coolant (Sept. 2014) I had a shop do it (time constraint) and they likely used 50/50 mix.

Using a coolant concentration calculator I estimated the current concentration mix to be just over 50% coolant vs distilled water.

[udidwht]

enblethen wrote:
My rig was getting slightly warm.
I took the A/C condenser loose and cleaned between it and the radiator. Got a lot of debris out. Fixed the cooling issue.

I was able take a peak at my front side of the radiator. Looked very clean. I have ordered some A/C condenser cleaner to clean the front exposed side of the A/C condenser and also ordered a fin straightener.

[enblethen]

My rig was getting slightly warm.
I took the A/C condensor loose and cleaned between it and the radiator. Got a lot of debris out. Fixed the cooling issue.

[udidwht]

Update:

I purchased a 30qt drain pan (plastic) and marked it in 1gal increments. What showed after draining was exactly 3gals but I did spill some during the drain that ran across the frame and onto me. So I'm guessing probably closer to 3.5gal.

Also hooked the A/C condenser fan to the battery directly and it does not work. Have one on order now. Here's a pic of the fan...

https://www.dropbox.com/s/oilh4kcssl2dkcn/IMG_0411%5B1%5D.JPG?dl=0

Have now replaced both radiator hoses and the bypass hose along with a new T-stat 195F

[udidwht]

77rollalong wrote:
I don't use pre mix when filling a flushed system, as the remaining water in the system will dilute the premix, even if you pull the lower rad hose there will still be water left in the block, and heater core. so i measure out how much pure antifreeze i need , then top off with water and will give the proper antifreeze to water mix.

You have a rough guess as to how much coolant is removed after pulling the lower hose vs what's remaining in the block (total capacity).

If I'm not mistaken coolant even in the concentrated form still comes at a 70/30 ratio. Not sure if one can even purchase 100% pure coolant at a local FLAPS.

[wolfe10]

I agree:

Final rinse with distilled water.

Pour in 50% of system capacity with coolant concentrate.

Top off with distilled water.

[77rollalong]

I don't use pre mix when filling a flushed system, as the remaining water in the system will dilute the premix, even if you pull the lower rad hose there will still be water left in the block, and heater core. so i measure out how much pure antifreeze i need , then top off with water and will give the proper antifreeze to water mix.

[udidwht]

77rollalong wrote:
5.0L (VIN H) 18q 17L
5.7L (VIN K) 17q 16L
6.5 Diesel
VIN F,P&S 26.5q 25L
VIN Y 24q 23 l
7.4L VIN N 23.0 q 22 L
On vehicles with rear heater add extra 3 quarts (2.8L) of coolant.
(from Mitchels ON-demand)

After I do a flush of a system, i just add half my capacity of pure coolant then top off with water, since the system is never completely empty after flushing.

Curious....why add the water if the coolant is already pre-mixed (either 50/50 or 70/30 concentrated)?

[77rollalong]

5.0L (VIN H) 18q 17L
5.7L (VIN K) 17q 16L
6.5 Diesel
VIN F,P&S 26.5q 25L
VIN Y 24q 23 l
7.4L VIN N 23.0 q 22 L
On vehicles with rear heater add extra 3 quarts (2.8L) of coolant.
(from Mitchels ON-demand)

After I do a flush of a system, i just add half my capacity of pure coolant then top off with water, since the system is never completely empty after flushing.

[udidwht]

enblethen wrote:
7.4 TBI
Yes, 6 gallons of premixed.

I see the Prestone has (2) the 50/50 (265 boil over) and Concentrated.

The concentrated shows it's a mix of 70/30 with a higher boiling point 276F with 15lb cap. Concentrated it is.

[enblethen]

7.4 TBI
Yes, 6 gallons of premixed.

[udidwht]

enblethen wrote:
My 1993 Chev Owner's manual says 22.5 quarts. This may not include the recovery tank.

I take it you have a 454?

I guess I was pretty close. I was thinking of getting 6 gallons and that should cover it and give me some to spare.

[enblethen]

My 1993 Chev Owner's manual says 22.5 quarts. This may not include the recovery tank.

[K_Charles]

Measure what you take out, that should be close.