Blknight692

Has anybody tried taking the rad out, capping the end and pouring CLR in it? Anybody have a clue what the core is made out of? Copper or Aluminium? I'm trying to buy me some time to get money to fix it right before I blow my engine up.

I'm running 50/50 in it. It got hot again on the way to work with the nice cool morning air so I know I'm in trouble this afternoon. Looks like I will be making a nature stop on the way home for a little bit. Will drain it and pull it this weekend and see what my options are. Thanks everybody.

Nope, it backed up when I flushed it. It was going through , but no where near what I was putting in. What options do I have then for the radiator? Is there a flush or do I take it out and have it boiled out? I've never done either.

I flushed everything with the hose when it was all open and it looked good. The only thing that was a little slow was the radiator. Filled it up, let it bubble for a few minutes, top it off, wait, top it off one more time and it was good. Should I take the radiator and have it boiled out? I need this truck as its my daily driver, but can't have it blow up on me either.

On the ride home yesterday my temp started climbing again. It hit about 220 or so before I had a chance to pull it over and let her sit for a bit. I'm at a complete loss now on what to do. Heres the laundry list of things I've done to it just about a month ago. Replaced thermostat, thermostat housing, upper and lower hoses, radiator cap and water pump. I don't have any water in my oil and or oil in my water so I don't know if its my head or not. Whats next? New radiator? Hahahaha, try and find one. Anybody have anything?

Where do I start with this mess? Seriously? Right now I do not have any major issues, but this looks horrible!

Update... Replaced the water pump, lower hose, upper hose, thermostat, upper thermostat housing with a cast iron one and the radiator cap. Filled it up with 50/50 and fired her up. Checked for leaks, good and clean. Took it for a 45 min. cruise and no issues. Woo hoo! While I was deep in there and had everything removed I took a look at my alternator bracket to find out what I was dealing with. It turns out that I was just missing the rear bolt. Took the forward one out and went and bought 2 M10x1.50mm x 30mm long, washers and lock washers. Slapped them in and everything went together easy, true and straight! I'm a happy boy and most of my charging issues are gone as well! Yay me! Thank you for all you help!

I think your right banzai on the water pump. I have it but didn't get to do anything yet. Just sitting around thinking and a thought hit me <crash, boom> well that was me falling out of my chair from the shock of me being so dumb. What if the lower hose has collapsed and failed. Every time I check it looks good but to hot for me to grab so I haven't. Went outside with Dr. Pepper in hand and grabbed it, yep, shes soft. Called up the parts store and will have one today, $13 for the lower and $16 for the upper. I'm gonna change them out and send some prayers to the Datsun gods...

Thanks for the advice banzai. I'm just thinking next logical step with the water pump. Its only $29 and can't hurt to clean everything else out. I've replaced the radiator cap already and on the thermo I drilled out the little bypass pin and ran it, still acting the same. I do not have a clutch on my fan but I also do not have a shroud around it. My fan is pretty nasty looking with it being made out of plastic. Can/should I change it? On a side note, I'm still having issues with my alternator bracket missing one of the bolts that go into the bottom of the block and so it allows the alternator belt to slip. I tightened the belt some more but now it doesn't charge as well. Did I make it to tight and would that have any effect on the water pump not working as well? Hmm, just might have to loosen it a bit and give that a try.

New update. Drove to work fine, temp hit 190 and stayed there. Later in the afternoon on the drive home I got about 5 miles from home from a 25 miles one way trip, and she started heating up. Got up to about 220 by the time I got home. Popped the hood and didn't see anything leaking. Waited for it to cool down then pulled the thermostat out, put it back together and took it for another drive to see if it changed or not. Temp started to climb, hit about 210 when I shut it off for the night. Called up Kragen and got a water pump on order, about $40 bucks without the clutch fan. Do I need a new clutch, didn't look like it had a clutch fan on. My fan is looking pretty nasty so should I get a new metal flex fan for it also? Any info would be great. Here is a pic of the thermostat housing back together.

Update, this weekend was an adventure to say the least. Got the part back from the ex and it looked real nice. Did a very good job getting the old bolt out. Props to them. Had to make a new gasket for the housing to the head and for the thermostat. I could get a new one for the head but the part that all of the shops in town had must be wrong. The had some piece that has like 12 holes and slots with tabs that wouldn't fit anything close to what I had. I wasn't the only guy looking for one this weekend, somebody else was looking for gaskets for a '72 521 and running into the same issue. Good to know I'm not the only one in town. I figured out that the proper bolt length for this is a M8-1.25 x 27mm, problem is you can only get them in 25mm or 30mm. 25mm is to short to have a lock washer under and 30mm needs 2 lock washers, so I double nutted them and cut them down, perfect fit. I had to make a few gaskets because I kept getting a leak through the bolt hole on the bolt furthest away from the head. Took it apart and put it back together 3 times before I found the top thermostat housing had a pretty nasty pit next to the bolt hole. Called around to see if I could get the top housing and was told it would take 4 days to get one, at the earliest! Forget it, ordered it so I will have it later and then proceeded to jb weld my existing one. After I let it set, filed it down and then made sure it was flat and smooth, put it together and poof, it was done, no leaks. I have got to give props to my friend Jamie for putting up with me all weekend and helping me out, Jamies wife Sheila for letting him play all weekend and to my ex's fiancé Tim for getting me out of trouble with that bolt. Here is a pic of the housing after Tim got done with it. I will have another later today of it all back together.

Thank you all for your advise. Just a follow up. I was able to get 1 of the bolts out with a pair of vise grips and pb blast. Worked it forward and back a few times and out it came. The other on, the one closest to the head, was a complete fail. Grabbed it with the vise grips and tried to work it and it snapped almost flush with the housing. Hit it with more pb blast and let it soak for a couple of hours then tried the ez out. Complete fail again, snapped the ez out. Called up a couple of local shops to see if they had just the housing and got nothing. So as a last resort, I had to make the dreaded phone call to the ex wife, who's fiancé is in charge of a machine shop in town. He said he could work on it today but 1 of 2 things would happen. Either he is going to fix it or mess it up. I told him I'm junk yard hunting anyway, so if he could fix it, hes saving my bacon. So we will see where I'm at this afternoon. Here are some pics of the housing.

I'm going to take the housing off and see how much bolt I have sticking out and see what my options are before I easy out them.

I used a 12mm socket to get them out, don't know if that helps anything or not. Both of them snapped real easy so they have probably been in there for a while, but go figure with the cathodic s of steel and aluminum, bad. Thanks.

My '71 521 pick up was starting to run a bit hot so I got a new thermostat and was going to put it in when I snapped off both heads of the bolts on the housing. Gonna try to get them out with easy out and some heat, already got them soaking with some pb blast. But once I get them out, what size do I need to go get now? I did some searching and all I can find is 8MM I think. I pulled that up off of the olddatsuns.com web page. Any help would be awesome. Thanks