Radiator overflow not returning to radiator overnight

Dealing with all subsystems specific to the diesel powered Datsun-Nissan 720 pickup trucks.

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asavage
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#46

Post by asavage »

Retaining clip: see this post and the ones below it.
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ecomike
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#47

Post by ecomike »

asavage wrote:Philip mentioned this exact bolt discrepancy in his Water Pump Thread. You didn't read that first??
I was right, Mine was a third version on the bolt length, or maybe the reverse of Philip's problem, but Philip mentions using 10mm longer bolts, which means he started with 30 mm and 35 mm long bolts???

I had to use shorter bolts for the new N pump on mine. I reused the shorter bolt for the long hole and replaced the longest bolt with a new 35 mm long bolt. So I used a 45 mm and 35 mm long, 8 mm diameter, x 1.25 thread on the two small bolts. The large bolt was the same length as before.
Regards,

Mike

1985 Jeep Cherokee Pioneer, 2WD, retrofitted with SD-22 & 5 spd manual trans, a 4X4 Gas Wagoneer ltd. (XJ) Jeep, 4.0 L w/ AW4 auto, and now 2 spare 2wd Jeeps, 87 & 89.
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ecomike
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#48

Post by ecomike »

asavage wrote:Retaining clip: see this post and the ones below it.
The last photos of Philip's newest, latest water pump, of the clip looks just like my new one. I think that earlier picture of the clip way up inside towards the impeller on the bad (first new) pump that died of Philip must be part of where it failed, or where it was missassembled. I remembered that photo and noted the difference in mine when I started to install it.

My old pump has an obvious place for the clip in exactly the same location as my new pump, but the clip itself is definitely missing. It did not move, and is not out of place, it is just entirely missing. Don't if that contributed to the pump sucking air problem.
Regards,

Mike

1985 Jeep Cherokee Pioneer, 2WD, retrofitted with SD-22 & 5 spd manual trans, a 4X4 Gas Wagoneer ltd. (XJ) Jeep, 4.0 L w/ AW4 auto, and now 2 spare 2wd Jeeps, 87 & 89.
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ecomike
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#49

Post by ecomike »

Update. Day one the overflow bottle filled up on a 70 mile round trip, 4 hour stop mid way, driving at 50-70 mph, AC running. Typical trip. I did note that the upper radiator hose was not stiff (typical of previous behavior for several years) and it was at about 7-8 psi in the radiator when I pulled of the freeway and parked. Overnight the coolant stayed in the over flow bottle as before. This was all after I ran the system for 60 minutes with out a radiator cap, and got it good and hot, and was sure I had all the air out of the engine and the thermostat wide open, great coolant flow..etc.

Next morning I transfered the coolant from the overflow bottle back to the radiator (like I have been doing for 4 years). Drove the same trip, but at lower peak engine RPMs. First stop, 35 miles, the coolant bottle was still where it started at that morning and the upper radiator hose was very stiff, indicative of about 16 psi of internal pressure. 4 hours later returned home, 35 mile return trip, same driving conditions and no change, upper radiator hose still rock hard, at about 16 psi, and no overflow to the coolant bottle the whole day. Outdoor ambient was up to 88 that day.

The most significant change I have seen since replacing the water pump is that the radiator hose is now getting a lot harder, much higher internal pressure, about double. With the old pump the system never got over 7 psi (verified with a gauge), now it seems to be getting up to or close to actual cap pressure. So it looks like we fixed something, but I am not sure I am out of the woods yet.

During the repairs I must have damaged the PO's bulb/capillary aftermarket coolant temperature sensor assy. It is dead, so for now I have been using 2 different hand held IR temperature testers to get some temp readings when ever I stop. It looks like the 180 F thermostat is stuck open currently, as I have coolant flow almost immediately at start up. I don't think that will be an issue till October or Nov. here. I am working on installing a Jeep Temp sensor in the thermostat housing that is compatible with the Jeep dash gauge and jeep harness wiring. So far I have not seen the temperature get over 180 F in the engine block or at the thermostat housing.
Regards,

Mike

1985 Jeep Cherokee Pioneer, 2WD, retrofitted with SD-22 & 5 spd manual trans, a 4X4 Gas Wagoneer ltd. (XJ) Jeep, 4.0 L w/ AW4 auto, and now 2 spare 2wd Jeeps, 87 & 89.
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ecomike
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#50

Post by ecomike »

Update:

I parked this beast to do other work on it and just recently started driving it again. At first it seemed OK (thanks to the new water pump, and WP gasket), but then I noticed the overflow bottle was not filling, and draining, so I checked the radiator and it was low. Several checks later it was still loosing coolant, not a lot, just a little, mostly on long highway trips, 2-3 hours, maybe loose a pint, but not always, sometimes it was losing anything. So I added some Bars leaks leak sealer pellets (light duty stuff).

Have only driven a little since then, but today I used a rented Block tester with a special diesel engine head gasket leak tester fluid to see if I had a head gasket leak after all. It passed, 4 times, with the same test fluid, ran it cold, hot, and two more times at high rpms hot. No sign of any exhaust to coolant leak. :D

Coolant system is holding pressure, and is not overheating. I am starting to wonder if the filler neck on the radiator has a vacuum leak. I am also thinking about going with a thermostat that has small bleed holes in it at 12 and 6 O'clock to pass any trapped air, or water vapor, to make sure the thermostat is seeing coolant on the back side all the time to make sure it opens when it should. I think I currently have the no air bleeder style that Philip was so fond of.
Regards,

Mike

1985 Jeep Cherokee Pioneer, 2WD, retrofitted with SD-22 & 5 spd manual trans, a 4X4 Gas Wagoneer ltd. (XJ) Jeep, 4.0 L w/ AW4 auto, and now 2 spare 2wd Jeeps, 87 & 89.
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kassim503
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#51

Post by kassim503 »

I know it might sound crazy, but did you check your cap? The outer seal may be getting flakey. They arent all that great. My gasser had a weeping HG and passed the chemical huffer tester. But definitley do try testing for a gasket leak visually. Drive the truck around until it gets to a little higher than normal temp ( beat on it a little to ensure a good heat soak) then open the cap and fill up the coolant to the top, and rev it. If the level of coolant starts rising and continually pours over the neck, it usually means a weeping HG.
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asavage
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#52

Post by asavage »

Mike doesn't have to work to beat it: he's pushing a JEEP with the aerodynamics of shoebox, with a 61 HP diesel!

Mike, have you thought about doing an oil analysis to make sure the OEM oil cooler isn't leaking to the crankcase? As hot as you run that thing, you might not notice the typical milky oil appearance, because the coolant loss is so little. The oil coolers aren't known for leaking to the inside, but I've seen at least two leak to the outside. See this post for more info.
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ecomike
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#53

Post by ecomike »

Well the verdict is still out. I added some Red Line water wetter to it a few days ago. I have taken several 60 mile round trips, and will take another today. I will check the rad again in a day or two. For now the overflow bottle level is stable again. It actually went up 1" and down 1" a few days ago on a 60 mile round trip. Yesterday, with AC running the thermostat housing read 180 F, after a mid afternoon trip on the freeway with AC running.

I don't really get it that hot. I did toss out a bad cap in my inventory after testing last week, but 4 others were still at spec.

I have wondered about the oil cooler, and have not run oil tests. The bars leak additive I put in 2 weeks ago might have sealed something, like an oil cooler leak. But I keep a close eye on the oil, and have seen no signs anywhere of coolant leaks to the oil. The one that alarmed me a few weeks ago looked like I had lost a pint in one trip. Then no losses since then?
Regards,

Mike

1985 Jeep Cherokee Pioneer, 2WD, retrofitted with SD-22 & 5 spd manual trans, a 4X4 Gas Wagoneer ltd. (XJ) Jeep, 4.0 L w/ AW4 auto, and now 2 spare 2wd Jeeps, 87 & 89.
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asavage
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#54

Post by asavage »

ecomike wrote:I don't really get it that hot. I did toss out a bad cap in my inventory after testing last week, but 4 others were still at spec.
Some radiator cap testers only test the bypass pressure. Kassim was talking about the outer gasket, which controls vacuum generation and being able to pull from the reservoir. I've had several rads with dented radiator fill openings, where that outer gasket would not seal. Symptom was always the same: coolant would travel out to the reservoir but not back to the radiator. The reservoir level would rise so far but no further, and the coolant level in the radiator would drop so far but no further too. If I added coolant to radiator, it would be pushed out to reservoir but not drawn back to radiator.
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ecomike
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#55

Post by ecomike »

Quite true. I have bought about 8 new caps in the last 3-4 years testing out the cap side. I had the radiator rodded out about a year ago, and cleaned and pressure tested, but they do not test the top seal either. The top seal looks fine, but I can not swear to a perfect seal between the neck and the radiator tank (Between the inner and outer cap seal areas).

Todays good news is that the radiator was totally full after about 4 days of use, and the overflow was normal too!

I have had concerns about the coolant hose fitting on the side of the block that feeds the oil cooler, for years, looks corroded, like there was a leak there (which is why I replaced the hose about 1.5 years ago), but I could not get the bolt holding it to the block to come loose.

For now I am back to monitoring it. Last changes I made were the cap, water wetter addition, and Bars leaks standard duty leak sealer.
Regards,

Mike

1985 Jeep Cherokee Pioneer, 2WD, retrofitted with SD-22 & 5 spd manual trans, a 4X4 Gas Wagoneer ltd. (XJ) Jeep, 4.0 L w/ AW4 auto, and now 2 spare 2wd Jeeps, 87 & 89.
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ecomike
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Re: Radiator overflow not returning to radiator overnight

#56

Post by ecomike »

Been too long since I updated this thread to recall where I was at. Settle it say once I replaced the water pump and water pump gasket (where the real leak was), and the hose to the overflow bottle IIRC I never had any more problems with this beast since my last post here. Put a ton on miles on it and it almost finished, just need to replace the head liner. The real problem for years was a bad water pump gasket on the suction side of the coolant pump. It held coolant in but let air in when the block pulled a cool down vacuum.
Regards,

Mike

1985 Jeep Cherokee Pioneer, 2WD, retrofitted with SD-22 & 5 spd manual trans, a 4X4 Gas Wagoneer ltd. (XJ) Jeep, 4.0 L w/ AW4 auto, and now 2 spare 2wd Jeeps, 87 & 89.
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Re: Radiator overflow not returning to radiator overnight

#57

Post by Nissan_Ranger »

Yeah, that was a long time for me to wait!!! :mrgreen:

N_R
The old 'six gun' was as popular as the cell phone in its time and just as annoying when it went off in the Theater.
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ecomike
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Re: Radiator overflow not returning to radiator overnight

#58

Post by ecomike »

LOL, But I hear some things are worth waiting for. :mrgreen:

Glad to see so many familiar faces still here :D
Regards,

Mike

1985 Jeep Cherokee Pioneer, 2WD, retrofitted with SD-22 & 5 spd manual trans, a 4X4 Gas Wagoneer ltd. (XJ) Jeep, 4.0 L w/ AW4 auto, and now 2 spare 2wd Jeeps, 87 & 89.
plenzen
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Re: Radiator overflow not returning to radiator overnight

#59

Post by plenzen »

Most of us just have no where else to go and nothing else to do.

Sad when you think of it.
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Re: Radiator overflow not returning to radiator overnight

#60

Post by Nissan_Ranger »

Let's just have a nice sit down in the garage and enjoy another brewski!
The old 'six gun' was as popular as the cell phone in its time and just as annoying when it went off in the Theater.
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