88 k1500 4WD Ext Cab coolant flush questions

[IndyAnne]

First, the vitals:
1988 Chevrolet K1500 4WD 5.7 gas extended cab

I want to replace the coolant mix in my truck, but I'm having trouble identifying the engine block coolant drains. Any help?

Also, is this gray valve patched into a line that goes between the firewall and the engine (see photos) an after-market "flush n fill" valve, or am I missing something in my guidebooks? I had not planned to buy a kit, I was going to follow my guidebook instructions. But, if this is part of a PO kit, maybe it would be easier to use than the engine block drains?

I know it says "Flush/Fill Connector" on the cap, but, I'm a little nervous, want to be sure.

I found the radiator drain, no problem there.

Thanks,

Newbie neighbor
Anne

[88K2500]

I don't think that came factory installed on the truck. I've only used the drain location at the bottom of the block and the radiator cap location when changing the coolant.

I like the block location because it's the lowest point of coolant flow. When you drain from there, you know your getting all the old coolant out.

Someone else might chime in about that grey flush valve but IMO all that looks like to me is another place for a leak to happen. I'd rather have a solid hose with two hose clamps rather than four hose clamps. You know what I mean?

On a side note, I'm in California so I don't even use much coolant/antfreeze. I put in just enough so that my radiator doesn't corrode within. I use like 10% coolant/90% water...Lol.

Good luck.

[Richardman1992]

im not sure, but imo, that looks like the port where ac refrigarant is added, like r12 or r134a. just my .02 cents

[ChevLoRay]

Prestone markets a flush kit. You should just look at one at WallyWorld or at their website.

[TennesseeZ]

Yes that is part of an aftermarket coolant flush kit, and it is installed in the right hose.

IIRC Prestone made some grey ones years back.

I have used them before, if you follow Prestone's directions and let the water run for the specified time you should be fine with doing it that way.

[ChevyTech]

I like removing block drains to flush the cooling system but on your 1988 the passenger side block drain has the knock sensor installed in it.

I suggest NOT removing the knock sensor just the flush the cooling system, unless the block has a serious buildup inside it. Knock sensors are more fragile than they look.

[IndyAnne]

I need to check my notification settings, just realized you replied -- thanks so much for the confirmation about the Prestone kit. I'll post some more pics and details soon.

[IndyAnne]

thanks for the knock sensor warning, I'll give the Prestone kit a try this week; I'm still working on electricals and ac issues

thanks!
Anne

posted from my iPhone

Originally Posted by ChevyTech

I like removing block drains to flush the cooling system but on your 1988 the passenger side block drain has the knock sensor installed in it.

I suggest NOT removing the knock sensor just the flush the cooling system, unless the block has a serious buildup inside it. Knock sensors are more fragile than they look.

[IndyAnne]

thanks for the tip, Tater Chip!

Originally Posted by TennesseeZ

Yes that is part of an aftermarket coolant flush kit, and it is installed in the right hose.

IIRC Prestone made some grey ones years back.

I have used them before, if you follow Prestone's directions and let the water run for the specified time you should be fine with doing it that way.

[IndyAnne]

hey, Ray,

it's great to get this mystery solved!

Thanks
anne

Originally Posted by ChevLoRay

Prestone markets a flush kit. You should just look at one at WallyWorld or at their website.

[IndyAnne]

OK, I need much more help. I checked out the Prestone web site and saw a video and printed out the written instructions. Two problems, because somebody did not have me in mind in technical writing class at Prestone: 1) the video instructions have nothing to do with the Flush-n-Fill kit, just the old way of doing things. Here's the link to the video:
http://prestone.com/carcare/howto.ph...=28#flashVideo

2) The written instructions leave a WHOLE LOT out. Here's the link to the written instructions:

http://prestone.com/products/accesso...p#accessories2

OK, I'll take responsibility: I guess I need more pictures and more steps spelled out for me like I was a 10 year old.

Here are my remaining questions:

1. If I use the TEE fitting that PO installed to do the flush on the heater core line, where is the flush fluid going to go? Am I supposed to drain the radiator first? Does the reservoir hold all of the flushed fluid? I can picture the flush line going into the TEE fitting, and the garden hose on the other end. I just can't see where all that waste water is going to go.

2. On the back flush, item #2: I guess I'm going to have to go back to the parts place to find out exactly what this means: When appropriate, snap Splash Tube into radiator neck and open radiator drain. *Turn on water to garden hose. *Check to see that liquid is emerging from the Deflector Tube or radiator hose fitting before proceeding.

Excuse me: when appropriate? I don't get it. Splash Tube? Deflector Tube?

3. I have a big ol 5 gallon bucket to catch the waste because my truck has 4.5 gallon capacity. I understand some of the fluid will remain in the system until the part where I am supposed to let the engine run until it is hot enough to open the thermostat. How will draining work after that?

4. The young man at the parts place said this would be a good time to replace the thermostat. At what point do I do that? I understand from my Chilton and the Haynes that the thermostat will be under the engine end of the top radiator tube, in line. If I had to guess -- I am guessing, after I drain the radiator is when I change the thermostat out. Will fluid spill out of the top radiator hose, since the thermostat will be closed? Will I need to move the bucket under this spot on the system, under the thermostat? Will fluid drain out of the engine side when I take out the thermostat?

That's enough. If anyone has the patience to wade through my confusion and help me out, I will be grateful.

Thanks,
Anne

[og350]

well when i flush then i just drop the coolant out of the radiator and then put a hose in the top and let it run for a while then fill it with water run the car.... let it cool.... then drop the radiator again and then fill with coolant water mix. in wisconsin we use 50/50 mix for the winters so you might just go 70/30 depending on how cold it gets there. if it gets elow freezing alot i would say just use premixed 50coolant/50 water and you will be fine! i have seen people use those flush valves and they do wok ok. i think you can put a hose on them and just run it with water but not sure. if you can not get the block drain out you can always punch a frost plug out anfter running water through the motor. lots of ways to do it and everyone does it different! good luck!! just remember after you do re fill it with coolant to check it a few times after you drive it some and get it hot to get the air worked out of it.
if you drain the radiator do you flush then drain it all again when it is empty is a good time to pull the thermostat out. it is two bolt and the you will loose a little fliud if there is any in the top hose but its ok it will wipe/ wash off after you bolt it back together!

[IndyAnne]

Thanks so much for your help! I'm probably over-thinking it, since I'm new at this, afraid of messing up.

Originally Posted by og350

well when i flush then i just drop the coolant out of the radiator and then put a hose in the top and let it run for a while then fill it with water run the car.... let it cool.... then drop the radiator again and then fill with coolant water mix. in wisconsin we use 50/50 mix for the winters so you might just go 70/30 depending on how cold it gets there. if it gets elow freezing alot i would say just use premixed 50coolant/50 water and you will be fine! i have seen people use those flush valves and they do wok ok. i think you can put a hose on them and just run it with water but not sure. if you can not get the block drain out you can always punch a frost plug out anfter running water through the motor. lots of ways to do it and everyone does it different! good luck!! just remember after you do re fill it with coolant to check it a few times after you drive it some and get it hot to get the air worked out of it.
if you drain the radiator do you flush then drain it all again when it is empty is a good time to pull the thermostat out. it is two bolt and the you will loose a little fliud if there is any in the top hose but its ok it will wipe/ wash off after you bolt it back together!

[ChevLoRay]

I think the deflector goes onto the filler neck. When you connect the water hose to the fitting on the heater hose and turn on the water....what gets added to the cooling system has to have a place to go, ergo the deflector should send the overage out onto something....just what is up for conjecture.

However, once you are done with the flush, you gotta get that now-diluted, non-coolant infested, water out so you can replace it with antifreeze/coolant.

It's like it never ends....

[IndyAnne]

Thanks, Chev!

OK, I'm going to just jump on into it. I figure people have been doing this themselves for many years, and I can, too.

Just one more question -- should I run the engine with just water, to bring it up to temperature and open the thermostat, to circulate out the coolant that is in the system behind the thermostat? Or is that what the heater core T fitting is for? Does the T line remove the engine block coolant?

I'm planning to use distilled water as recommended, since our Indiana water has a lot of minerals in it.

Originally Posted by ChevLoRay

I think the deflector goes onto the filler neck. When you connect the water hose to the fitting on the heater hose and turn on the water....what gets added to the cooling system has to have a place to go, ergo the deflector should send the overage out onto something....just what is up for conjecture.

However, once you are done with the flush, you gotta get that now-diluted, non-coolant infested, water out so you can replace it with antifreeze/coolant.

It's like it never ends....

[IndyAnne]

http://www.nissanforums.com/ga16de-1...tml#post786772

Sometimes these links evaporate, so I'll copy the text here:
- Install the garden hose adaptor in one of the heater hoses.
- Put the deflector in the radiator to direct the water away from the engine. (it may not fit, though)
- Drain the radiator and leave the drain open.
- Attach the hose and turn on the water.
- Put the heater on the highest temperature setting.
- Start the engine after water starts coming out the deflector.
- Run the engine until the water coming out the deflector is clear. (Rev it several times to help remove deposits.)
- Shut off the engine and let the radiator drain. If you have a block drain, remove it.
- Remove the hose and put the cap on the adaptor.
- Replace the block drain plug (if any) and close the radiator drain.
- Fill with anti-freeze/ water mix. If your vehicle has an air relief plug, remove it and fill till anti-freeze comes out the plug, and then replace the plug.
- Put anti-freeze in the remote reservoir up to the cold line.
- Leave the radiator cap on loosely
- Run the engine until the thermostat opens (the upper radiator hose will get hot). The water level in the radiator will drop as water enters the engine.
- Add anti-freeze to top off. Tighten the radiator cap. Let the car cool.
- Check the reservoir, and add anti-freeze, if necessary.
- Remove the radiator cap and check that the radiator is full. Add anti-freeze, if necessary.
- Drive the car until it warms up. Then let it cool.
- Check the reservoir, and add anti-freeze, if necessary.
- Remove the radiator cap and check that the radiator is full. Add anti-freeze, if necessary.

Check the reservoir in the morning for a few days, just to be safe.

Lew

Originally Posted by IndyAnne

Thanks, Chev!

OK, I'm going to just jump on into it. I figure people have been doing this themselves for many years, and I can, too.

Just one more question -- should I run the engine with just water, to bring it up to temperature and open the thermostat, to circulate out the coolant that is in the system behind the thermostat? Or is that what the heater core T fitting is for? Does the T line remove the engine block coolant?

I'm planning to use distilled water as recommended, since our Indiana water has a lot of minerals in it.

[ChevLoRay]

I think that's what you do. When it says to run the heater at its' highest setting, they mean temperature. If it (the engine) isn't running, it can't functionally eliminate the water/coolant in the heater circuit. You're dependant on the water pump to circulate the coolant, too.

[TennesseeZ]

Originally Posted by IndyAnne

http://www.nissanforums.com/ga16de-1...tml#post786772

Sometimes these links evaporate, so I'll copy the text here:
- Install the garden hose adaptor in one of the heater hoses.

PO did this for you

- Put the deflector in the radiator to direct the water away from the engine. (it may not fit, though)

Deflector, or splash tube, both are the same thing. It's the long tube bent almost in a 90 in the kit. It is hard to get in, keep trying and you'll get it. If needed, sand the ring down a little where it snaps in the radiator.

- Drain the radiator and leave the drain open.

Drain it into a pan or bucket and safely dispose of it, antifreeze is toxic to animals and they like to drink it.

- Attach the hose and turn on the water.

You'll need the adaptor from the kit. Looks like two female hose ends with a short tube between them. Look inside, one end is open, the other closed. The closed end goes on the T fitting in the heater hose. It is a check valve, only allows flow one way.

- Put the heater on the highest temperature setting.

On 'HI" to get max flow thru the heater core. Fan can be on "LO" or off.
Turn on the hose and make sure water comes out the deflector tube.

- Start the engine after water starts coming out the deflector.
- Run the engine until the water coming out the deflector is clear. (Rev it several times to help remove deposits.)
- Shut off the engine and let the radiator drain. If you have a block drain, remove it.
- Remove the hose and put the cap on the adaptor. (T fitting in heater hose)
- Replace the block drain plug (if any) and close the radiator drain.

Replace the thermostat now if you choose to. If the one in it works, I wouldn't.

- Fill with anti-freeze/ water mix. If your vehicle has an air relief plug, remove it and fill till anti-freeze comes out the plug, and then replace the plug.

If you did not remove the block plug, just pour a gallon of straight A/F in, there will be enough water in the engine to dilute it. Then use A/F-water mix for the rest of the steps.

- Put anti-freeze in the remote reservoir up to the cold line.
- Leave the radiator cap on loosely
- Run the engine until the thermostat opens (the upper radiator hose will get hot). The water level in the radiator will drop as water enters the engine.
- Add anti-freeze to top off. Tighten the radiator cap. Let the car cool.
- Check the reservoir, and add anti-freeze, if necessary.
- Remove the radiator cap and check that the radiator is full. Add anti-freeze, if necessary.
- Drive the car until it warms up. Then let it cool.
- Check the reservoir, and add anti-freeze, if necessary.
- Remove the radiator cap and check that the radiator is full. Add anti-freeze, if necessary.

Check the reservoir in the morning for a few days, just to be safe.

Lew

Gotta put something down here to post the above.

[IndyAnne]

TNZ-- thanks so much for the detailed instructions. I'll let you know how it goes.
Anne

Originally Posted by TennesseeZ

Gotta put something down here to post the above.

[TennesseeZ]

One more thing, if your system is really, really rusty this is a good time to use a bottle of Prestone (etc) Super Flush or similar. They make several kinds.
Drain enough coolant from the radiator (if needed ) and pour it in. Drive the truck 3 hrs (or more, and doesn't have to be all at one time), then proceed to step 1 above. You'll drain this with the coolant, then flush the system with the clean water from your hose.

[IndyAnne]

TNZ: Thanks very much. This is going into my growing folder of great tips from the forum as I work through my first truck projects.

Originally Posted by TennesseeZ

One more thing, if your system is really, really rusty ...