I have a 1991 Nissan D21 Pickup - Base Model 4 cyl. I would like to flush the radiator. I do not have a manual and not sure how much the radiator will hold. Does anyone know if it needs all 50/50 or the full high mileage antifreeze?

300,000 + miles but most of the engine is newer.

Your engine requires approximately 2.37 gallons of a 50/50 mix of coolant and distilled water (entire capacity including overflow reservoir). Conventional green should work fine.

As TC said, get a gallon of distilled water and a gallon of coolant which is usually enough for these trucks. Mix it 50/50 and it wouldn't hurt to add a little Redline Water Wetter. Get one of these... Lisle spill free funnels if you don't already and have at it. Don't forget to vent the bleed port on the intake manifold. Use a 10mm socket to remove the bolt. Pour coolant into the funnel and watch for coolant to geyser out of the bleed port. Once the coolant pours out without any air bubbles then you are ready to close that port with the bolt you removed earlier. Run the engine with the funnel still in place. Fill the funnel about 1/3. Run the engine until the thermostat opens. Done, cap on, Drive.

I am draining my cooling system today but for some reason I cannot find my truck manual. I am not sure how many gallons of coolant are needed to refill the tank & reservoir. Can anyone confirm the correct amount?

1991 Nissan D21 Pickup 2WD Base - 4cyl

Thank you

Approximately 2.13 gallons including the reservoir.

Why did you start another thread about the exact same thing? Please check your first thread about this.

I watched this youtube video from prestone and was wondering if this process would work for a novice?

I have the 1991 Nissan D21 Pickup - 4cyl 2WD

Youtube Video ---> http://www.youtube.com/watch?v=i36pDzhFkBQ

Please let me know if there is anything different I would need to do from this video. Thank you!

Pretty through, if the coolant looks brownish or has sediment I like to remove the heater hose and flush it out with the hose. I use a kit like the Prestone coolant flush tee for dirty, neglected systems. Many quick lubes will take your used antifreeze for recycling. Good luck.

Flushing the entire cooling system on a the KA24E block according to the FSM is fairly straight forward.
Here is the FSM Directions on flushing the cooling system on a most Nissan D21s. FSM is for KA24E:



When running a cooling system cleaner, draining the block plug helps a LOT. The sediment and scale i've seen come out is crazy considering my regular cooling system maintenance.
The block plug is the annoying part.

Here is a short video showing where the coolant drain plug is:



Tools needed:

1. 1-inch 14mm socket
2. 8-inch flex head ratchet, or regular ratchet which will require #3 on this list .
3. 6-inch extension
4. 2-inch ‘90 universal joint adapter

You wont need the extension when going at it from below.

Below are steps that from another D21 owner wrote up:

Steps:

1. Hang a light off the brake line for max visibility. You’ll be able to see the bolt if you lean far enough back…..see video above for the “sweeping in” view.
2. Put the ratchet setup UNDERNEATH the small EGR exhaust tube, and in between the dipstick and the firewall, and you’ll literally be able to snag the top of the bolt easily sliding the socket up and down against the block until it catches and attaches smoothly. Once you feel it catching you can probably lean back/adjust light if needed and see it directly to help attach if necessary. It should attach very cleanly and flush to the block with no risk of stripping and lots of room to maneuver.
3. Once attached, if it’s the first time removing it (I had to remove it 6-7 times flushing the radiator before it was clean), you can swing the ratchet up from the position in the first picture below; and you’ll have tons of room to attach something as a breaker bar (I used an extension and deep-well socket).
4. Once you remove it the first time, there’s no need to add thread sealant per the FSM or even tighten it back down past snug to keep flushing the system, as I never leaked a drop doing it that way while the engine ran for 20 minutes each time. I would add the thread sealant when putting it back in for the final coolant fill though.

Here is a longer video showing how-ish i did it the first time: