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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rlaggren
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#31

Post by rlaggren » 13 years ago

If the overflow bottle has the hose through the cap with a dip tube into the bottom the dip tube (the part above the water level) and cap (w/nipples) is part of the circuit. Might want to look at those - maybe remove the cap/dip-tube, wet the whole thing in a soapy water solution then pinch one end off and apply a little pressure at the other end.

Does it work differently depending on the water level in the bottle?

Rufus

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philip
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#32

Post by philip » 13 years ago

rlaggren wrote:If the overflow bottle has the hose through the cap with a dip tube into the bottom the dip tube (the part above the water level) and cap (w/nipples) is part of the circuit. Might want to look at those - maybe remove the cap/dip-tube... -snip-
Rufus
That's a GOOD suggestion. When one pulls up the overflow tank cap, there has to be a 4" tube so that excess coolant can be pulled in as the engine cools off!

Did ANYONE mention this? :wink:
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-Philip
Passed 08May2008
My friend, you are missed . . .

1982 Datsun 720KC SD-22

"Im slow and I'm ahead of you"

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ecomike
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#33

Post by ecomike » 13 years ago

No one has suggested that here before so might apply others, but in my case the hose is attached to the bottom of the overflow bottle so its not an issue on mine.
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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#34

Post by ecomike » 13 years ago

Update: I have been too busy driving this beast to work on it since my last post, i.e. to take it out of service to replace the water pump, and manifold gaskets sitting in the back seat. It's the only DD I have at the moment with a working AC right now. Good news is it has been behaving itself much better the last 6 weeks, meaning the radiator/coolant system has been drawing all (or at least 90%) of the coolant back in from the overflow bottle most (90%) of the time. Still planning the manifold gasket and water pump work as soon as some cooler weather arrives.
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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#35

Post by ecomike » 12 years ago

Well I made it all the way to the New Year with out being forced to replace the water pump, etc. Unfortunately, I found two puddles of coolant under the engine yesterday morning that I could NOT ignor. So it looks like the fun is about to begin. :shock:

Oh, and there was a drop of coolant on the bottom rear of the harmonic balancer just above the first puddle, under the water pump, ( I even took a picture of it for Philip!) so it looks like Al may have been, or should I say WAS right :wink: about the water pump seal sucking air and being the source of air getting into the radiator.

The last 2 nights here it finally got down to about 30 F, which I suspect was finally more than the water pump seal could handle.

Guess I got my moneys worth out of this beast and its old water pump though! :D as I put nearly 6,000 miles on it since September.

The second puddle, or leak was from the oil cooler coolant return connection or hose on the engine block. I had tried to remove that connection last year when I replaced the hose, but never got it to budge so I worked around it to replace the hose, which was no easy task.

Temporarily, out of necessity, I added some fiber pellets, bars Leaks brand leak sealant to the coolant, topped off the coolant and fired it up, drove it a good bit yesterday and today, and so far no more leaks at all under pressure or overnight last night, but it was nice and warm here last night. Meantime I am now rushed to get one of my other vehicles back on the road so I can park the SD22 jeep. Been working 60 hr weeks lately and have had little time for DD maintenance.

Anyway I took a few pictures that I will post shortly.

Oh, and I had a radiator pressure test run yesterday afternoon on the entire system to confirm that there is no head gasket leak. :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.

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ecomike
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#36

Post by ecomike » 12 years ago

Well I pulled the water pump yesterday. It was the cast iron pump and it did not look very old considering the probable age of the engine itself. I did not see any external signs of pump seal leaks on the bottom, but I did see red rust outside of the sealing area of the water pump gasket where it seals to the engine block. Also the water pump bolts were not very tight. They came off real easy. So I suspect it may have been a leak at the water pump to block gasket.

I am looking for new water pump bolts now while I have it apart, as I don't trust reusing these old bolts. I suspect I may have a good spare pump now, but no way to know for sure.
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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#37

Post by ecomike » 12 years ago

I had little to no luck finding new water pump bolts today. Luckily the two smaller bolts (8 mm) cleaned up nicely and are in really good shape, but the larger bolt has some corrosion on the back 1/2 of the threads that did not clean up with a wire brush. Since the bolt was not noticably tight I fear I might need some of that rusted thread to get a seal on the water pump gasket.

I broke down and finally bought a metric tap and die set (so much for the US SAE standard hold outs) so I can clean up the corroded threads. The larger bolt is a 10mm-1.25 pitch bolt and it is 65 mm long (an odd length). I found a new zinc plated bolt, 75 mm long bolt that I can cut to length, so either way I will need the die set to clean up the threads.
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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#38

Post by ecomike » 12 years ago

I also got a little bit of work done on this today. I used my new tap and die set and was not too impressed with the Harbor Freight die set's tool holders. Not a big surprise. Cleaned up the threads on the 2 smaller 8 mm bolts and the female threads in the block. I did some checking, measurements, and the bolts need to be able to just about bottom out in order to seal the water pump gaskets.

I suspect after further inspection that either the bolts were not seated all the way in, and or the block had not been cleaned on the top side near the head gasket where the rear of the water pump nearly touches the block before the last water pump was installed. The water pump I removed did not look very old. There was some white calcium scale and red rust above the water pump to block gasket seating area that indicated a slow leak at one time. I am also pretty sure that is where the water pump was sucking in air. I will try and post some pictures.
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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#39

Post by ecomike » 12 years ago

Does anyone see any problem with adding a water pump gasket sealer to all four sides of the water pump gaskets? Or 3 sides?

I am leaning towards making sure I get a good seal on this pump, especially after looking at the water pump housing / gasket / thin steel plate / second gasket / engine block sandwich system they use. Needless to say it worries me having 2 dry gaskets on both sides of that thin steel plate and only three light duty bolts. I am thinking of using water pump gasket sealer on the water pump to steel plate gasket, both sides, then again on the flat steel plate to second gasket, then go dry gasket to engine block (no sealer) for the last side so that it won't be too hard to remove the pump someday.

Any thoughts on this?

I typically avoid the gasket sealers, but.
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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#40

Post by asavage » 12 years ago

One word: RTV.

No need for coating multiple surfaces, good to excellent bonding if all oils are removed, very compliant to mismachined surfaces or poor surface condition.

And available in four designer colors ;)

Tip: use less than you think. Like toothpaste, more is not better. A thin coat -- enough that you can see the color of it, if you're not using a clear RTV -- is all that is necessary, unless you have odd interfaces such as vee engine intake manifold-to-head sealing, or some oil pan interfaces to the timing cover. Paper-style gaskets can use just a thin layer; anything more is just waste and looks bad too.

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ecomike
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#41

Post by ecomike » 12 years ago

asavage wrote:One word: RTV.

No need for coating multiple surfaces, good to excellent bonding if all oils are removed, very compliant to mismachined surfaces or poor surface condition.

And available in four designer colors ;)

Tip: use less than you think. Like toothpaste, more is not better. A thin coat -- enough that you can see the color of it, if you're not using a clear RTV -- is all that is necessary, unless you have odd interfaces such as vee engine intake manifold-to-head sealing, or some oil pan interfaces to the timing cover. Paper-style gaskets can use just a thin layer; anything more is just waste and looks bad too.
Is RTV a real word? LOL! I decided for fun to look up the acronym, as it dawned on me I never knew what RTV stood for, and I was having trouble remembering what to call the stuff I bought (RTV silicone..stuff). Turns out it means "Room Temperature Vulcanizing".

Anyway I think I bought Permatex brand, RTV, or at least a close cousin that is specifically for water pump and thermostat gasket sealing areas, and it's specifcally good for antifreeze glycol exposure.

Normally I would only coat one of two surfaces, IF any at all, in fact I usually avoid using the stuff, but this damn thing has four metal surfaces and four paper gasket surfaces in a sandwich between the engine block and the pump housing, so it has me a bit concerned and I am leaning towards a little over kill (like I said I would not normally use the stuff at all), but there were signs of leakage on the back side, and signs of possible poor cleaning before the last install by others but who knows, so I was thinking a little extra sealant might be a good idea.

So Al, How many and which surfaces would you coat if you were not sure all the surfaces were all good and flat? Its the thin metal plate that worries me and the potential for it to be slightly warped. I am still leaning towards doing the three and leaving the engine block surface (the fourth) with out RTV.
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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#42

Post by asavage » 12 years ago

Yup, you got the correct acronym.

If you assemble it relatively fast, before a significant skin occurs on the RTV, you can use RTV on both sides of each gasket.

In the illustration below, you want RTV on both sides of gasket 20014 (water pump to backer) and gasket 21074 (backer to block):
(click on image for larger)
Image

It's best if the parts are assembled "wet", so lay out your bolts beforehand, and if you're inclined do a trial fit (screw all the bolts in loosely) to make certain that there are no unexpected delays when the RTV is applied.

Oil and delayed assembly are the enemies of RTV . . . and gasoline will melt RTV too, so never use it where liquid gasoline might touch it.

While we're discussing RTV . . . one downside of RTV is that while curing it outgasses acetic acid, which is pretty corrosive to certain materials, notably aluminum alloys. For this reason, don't use RTV much or at all on sealed aluminum assys that could harbor the acetic acid. Example: alloy covers on motorcycle cases.

RTV is fine if the acetic acid can evaporate on both sides of the assy.
Regards,
Al S.

1982 Maxima diesel wagon, 2nd & 4th owner, 165k miles, rusty & burgundy/grey. Purchased 1996, SOLD 16Feb10
1983 Maxima diesel wagon, 199k miles, rusty, light yellow/light brown. SOLD 14Jul07
1981 720 SD22 (scrapped 04Sep07)
1983 Sentra CD17, 255k, bought 06Jul08, gave it away 22Jun10.

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ecomike
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#43

Post by ecomike » 12 years ago

I grabbed both old and new water pumps on my way to the parts store today to get a 1/2 threaded by hose nipple for the new pump, as I had overlooked that need previously. While at the store I had both pumps setting side by side on the counter and noticed the castings are not the same after all!!!!

Turns out the part of the casting where the two smaller bolts go through the housing are a different thickness than the old pump, enough so that the bolt length will need to change to use the new pump, a good 1/2" on one of them from the looks of it. I will be taking the new pump and old bolts back in the morning to get the right length bolts so I can use the new pump.
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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#44

Post by asavage » 12 years ago

Philip mentioned this exact bolt discrepancy in his Water Pump Thread. You didn't read that first??

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ecomike
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#45

Post by ecomike » 12 years ago

asavage wrote:Philip mentioned this exact bolt discrepancy in his Water Pump Thread. You didn't read that first??
Uh, :oops: now that you mention it, I read it about 6 months ago, just before I went pump shopping. I tend to forget little things like that after six months. :oops: which is how long it took me to finally getroundtoit to replace the pump.

But in all honesty, I think I blew past that part looking for the where and what brand pump to buy, and not to buy, and that pump was the bad brand, GMB wasn't it, the one that failed on him?

Mine has the N and Japan on the steel casting, came from NAPA. Philip did not mention if his new N pump also used the longer bolts.

Also, before I forget, I will try an post some pictures I took in that thread of the seal area on my old and new pump. My new pump has a metal wire clip protruding from the exposed bearing seal area that is missing from my old pump! The shaft / bearing seal assy did not shift on mine like the GMB did on Philip's, inspite of the missing clip on mine! I found that interesting. I am hanging onto the old pump as it looks almost new still, so I might try rebuilding it one day, but it is missing the clip.
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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