Go Back   Infamous Nissan - Hardbody / Frontier Forums > Tech Area > Engine and Drivetrain

Reply
 
Thread Tools Display Modes
Old 05-11-2010, 06:48 AM   #1
86 720
 
Join Date: Feb 2010
Location: Mesa
Posts: 36
Vehicle: 1986 720 PU
Thanks: 0
Thanked 1 Time in 1 Post
Default Cooling System Overhaul

Coolant system overhaul!

Noticed I was leaking coolant from the bypass coolant hose going from the thermostat to the manifold underneath the carb.. From their the coolant goes to the heater core and than to the block. The coolant travels through the block to the water pump which in turn pumps it back through the system.

Tool/items needed:
standard screw driver
phillips head screw driver
12, 10, 8mm open end wrenches
upper / lower radiator hose
bypass hose
heater core inlet / outlet hose
hose clamps
3 gallons extended life coolant
thermostat with gasket
radiator cap
new or rotted radiator
water pump
rtv sealent
coolant reservoir hose

Drain radiator and dispose of coolant properly. There should be 9-10 quarts (2-1/4 - 2-1/2 gallons).

Remove upper radiator hose and the two thermostat housing bolts, remove thermostat and clean surfaces of all gasket remnants. Remove lower radiator hose. Picture shows lower radiator hose with upper hose and thermostat removed.


Lower hose removed. Clean surface of inlet.


Remove radiator and fan shroud. Fan shroud has three phillips head screws, radiator has 4 bolts. Remove shroud first than push it up against the engine. Remove the lower radiator hose and slide up radiator. Remove shroud.

Water pump removal. Scrape surface clean of gasket remnants.


Water pump removed, judging by the impeller, this was a replacement.


New pump. This one directed extended life coolant be used. Note the impeller is cast iron.


Water pump removed. Note the orange-brownish sludge.


I opted to get my radiator rotted out rather than new. Cost 1/2 the price of new and is just as good. The person who did it said it was one of the worst he'd seen. Rotted just means the clean all the crap out of it, pressure and leak test it, paint it black and install a new petcock valve as well as neck extension for the reservoir tank.


You can see the engine inlet above the starter. This is where the new heater core hose attaches.


And with hose attached: above starter. I wasn't able to show the bypass hose connection because I couldn't get the camera under there. It is located directly underneath the carb. just trace the hose with your hand. You can see the outlet if you follow the fuel line from the fuel filter.


Water pump installed.


Do NOT tighten the lower radiator hose until after the radiator has been bolted onto the truck and the alternator has been set in place. My hose was touching the alternator pulley, and I had to go back and move the hose around a little. Tighten the lower radiator hose clamp before the fan shroud.


Double check all clamps and hoses for clearance.


Haynes calls for 9-10 quarts (4 quarts to the gallon = 2-1/4 - 2-1/2 gallons).


Pour 1 gallon into the radiator and let it settle for a few minutes. Fill the coolant reservoir tank to MAX. Start the truck and let it run until it gets hot. Make sure to watch the lower radiator hose for clearance. Shut truck off when it gets hot. Let it cool to 1/2 temp. and re-start. The lower radiator hose should compress as the water pump is creating vacuum trying to pull more coolant from the radiator. Turn truck off and you should hear sucking sounds from the coolant reservoir tank. The cooling is creating a vacuum from the tank to the radiator. When the tank is empty, refill to MAX and repeat the procedure until there are a minimum of 9 quarts of coolant installed. Verify with your year of truck.

Drive around for awhile, at least long enough to get the temp. at normal operating level. Park it and let it cool down. Re-tighten ALL the clamps to all the hoses at this point, especially the bypass hose underneath the carb. Use a 1/4" drive socket on the hose clamps to tighten them even further than allowed by the flathead.

Total overall cost:
$160.00
__________________
1986 Nissan 720 PU
285K miles
6K HIDs
Blue stealth lamps

2007 Nissan Titan
5K HIDs
Stainless Steel bug shield
Diamond Plate toolbox

1972 Datsun 510 2DR
- PROJECT
86 720 is offline   Reply With Quote
Thanked by:
cuz97 (01-29-2017)
Old 01-29-2017, 07:08 PM   #2
cuz97
 
cuz97's Avatar
 
Join Date: Jul 2012
Location: Elizabethton tn
Posts: 170
Vehicle: 97 nissan hardbody truck
Thanks: 3
Thanked 6 Times in 6 Posts
Thumbs up

You did a great job, There was very little of the pipe on the pass side to hook to, We used 1/2 copper pipe with nipples in them. Just got them done. two test drives looks good.

Cost O we used what was laying around.
__________________
cuz97
cuz97 is offline   Reply With Quote
Old 02-27-2017, 09:59 PM   #3
Rub3n
 
Join Date: Feb 2017
Location: New orleans
Posts: 2
Vehicle: 1995 Nissan Hardbody
Thanks: 0
Thanked 0 Times in 0 Posts
Default

I think I'm having an issue with my truck running hot I'm not sure what it is. There are no leaks from the radiator. Any idea what temp these trucks usually run at?
Rub3n is offline   Reply With Quote
Old 02-28-2017, 01:11 AM   #4
SBJ
Total Buzzkill
 
Join Date: Nov 2016
Location: OR
Posts: 1,477
Vehicle: '90 D21 4cyl 5spd 2wd
Thanks: 158
Thanked 165 Times in 153 Posts
Default

Quote:
Originally Posted by Rub3n View Post
I think I'm having an issue with my truck running hot I'm not sure what it is. There are no leaks from the radiator. Any idea what temp these trucks usually run at?
I would guess it's either water pump or thermostat related. Also check if your windows steam up when the heat comes on, that's a dead giveaway your heater core is leaking. I am running a 170 degree thermostat in mine, 180 makes it run a little too warm.
SBJ is offline   Reply With Quote
Old 03-01-2017, 10:34 PM   #5
Rub3n
 
Join Date: Feb 2017
Location: New orleans
Posts: 2
Vehicle: 1995 Nissan Hardbody
Thanks: 0
Thanked 0 Times in 0 Posts
Default

Quote:
Originally Posted by SBJ View Post
I would guess it's either water pump or thermostat related. Also check if your windows steam up when the heat comes on, that's a dead giveaway your heater core is leaking. I am running a 170 degree thermostat in mine, 180 makes it run a little too warm.
So I went to replace the thermostat today and there wasn't one to replace. I'm confused as why there wasn't one there.
Rub3n is offline   Reply With Quote
Old 03-02-2017, 12:54 AM   #6
Deerhurst
4/86 SE-V6 2 tone 4x4 HB
 
Deerhurst's Avatar
 
Join Date: Apr 2013
Location: Oregon
Posts: 5,041
Vehicle: 1986.5 Hardbody
Thanks: 698
Thanked 460 Times in 426 Posts
Default

Nice write up man!

Only 2 things I would add since this is a sticky; what motor you were working on (as there are 3 different ones in the hardbody in the US alone. The z24i, VG30i/e and KA24e). Judging by being a 720 its a z24i. And second, any part numbers you might have for things you replaced.

If anyone needs it the VG30i thermostat is 170F from the factory. The Duralast 170F VG30i has a barcode number of 9930403947 and 3947 on the tag.
__________________
1986.5 SE-V6 4X4 D21 Hardbody
Pacesetter Long Tube Headers
Morimoto Mini D2S HID Projectors and Hella 500s
VG33i
Deerhurst is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 03:53 PM.


Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.