Olds truck overheating Rad clogged with fibers

[Guest Bob Kerr]

I have been working on my 23 Olds 1 ton and it has been running ok just around the house or block, but if I get it down the road a bit it wants to over heat. It has a water pump which I have tightened several times. Is it possible the packing is getting sucked in to the water pump and then clogging the tubes on the radiator? OR I know it may be possible that there may be an old mouse nest in the back of the block or head or even the upper radiator tank but haven't found one yet. The fibers are simillar to cotton waste and I thought the old packing was asbestos with graphite.

[Mark Shaw]

Sounds like you need to do a good back flush on the radiator. Do the engine block while you're at it too.

[1929Chrysler]

Bob,

When you flush the radiator, flush it from the bottom up because what ever is getting in the radiator is coming from the upper radiator hose into the top of the radiator. If you were to flush from the top down, you would only push what ever it is further down into the core. You might want to put a filter in the upper radiator hose until you figure out what is going on.

Dan

[Guest Bob Kerr]

I should add that I have already had the radiator off and it does have a modern core in it. I flushed it with a hose while upside down and got a lot out but don't have enough flow/pressure here to do a good job. That radiator is HUGE, very thick! I also had the water pump out and the upper hose connection off and couldn't see anything like a mouse nest in side the block, but I couldn't see very far inside either without pulling the head. What I really need to know has anyone had problems with water pump packing getting into the tubes on a 20s or late teens vehicle?

[Guest]

Instead of pulling the head why don't you just knock out all the core plugs. Then you could clean the water jacket out properly.

[Guest elmo39]

Bob just back flushing with a hose is usualy not good enough you need some air pressure added, that is how it used to be done in the old radiator shops . I made my own pressure flushing gun and it works very well , basicaly what i did was get a piece of pipe the same size as the inside of the bottom hose ,brazed a hose fitting in one end and part way along brazed in a tyre tube valve fitting ,if you make one remove all the interior of the valve before brazing as there is a rubber seal inside it . fit the radiator hose end into the radiator hose, connect the water hose and air hose turn on the water full, after the water starts flowing give it an occassional blast of air (no more than a few lbs or you could blow your radiator, i use no more than 10-15 lbs max and usualy less. don't try this with a modern plastic radiator , they are only glued together and could blow to bits.

[Mark Shaw]

A 1923 honeycomb radiator is not designed to handle 10-15 lbs of pressure. I suggest you remove the radiator, and back flush it up side down on your lawn.

First put the cap on and hold your hand over the inlet (now at the bottom) while you fill the radiator from the outlet (now at the top). Remove your hand from the inlet when it is full. Repeat this several times until all the water coming out is clear.

Then partially fill it again and slosh it back and forth in various positions several times to break loose any more debris. Repeat the flushing cycle until the water is clear again.

Test the flow by standing the radiator upright against something to hold it at about a 30 degree angle. Fill the radiator while holding your hand over the outlet (now at the bottom). Remove your hand and watch how far the water shoots out of the outlet. If it shoots over a foot, you have enough flow. If it is considerably less, you probably need a new core.

[1929Chrysler]

I would also add that if you had anti freeze in the core this could add to a sticky residue that will hold on and act as a glue so to speak to the fibers. It might be a good idea to soak it in a Calgon dish washing detergent to disolve any sticky residue from the anti freeze before flushing.

And while I would agree that these radiators were in no pressure systems they were still dipped in solder which makes them pretty strong. A couple lbs of pressure shouldn't hurt but be carefull.

Dan

[Guest Paterson Chris]

I don't know if your problem has been solved already or not but I'll kick in my two cent's worth anyway as I've been sporadically working on my own water pump lately as well. Also, I noticed that some of the others didn't directly answer your question regarding the possibility of fibers migrating from your water pump to the radiator.

First, I've learned from others -- mostly in the marine trade -- that your water pump is supposed to maintain a running leak at all times when the engine is running. A few drops per minute. By tightening the packing nuts to where it doesn't leak, you're setting yourself up for a situation where the packing will burn up and begin to fail and more importantly, it'll then be so tight that it begins to score and cause abnormal wear to the shaft -- which means more leaks followed by you tightening the packing nuts again and thus a vicious circle. The water slowly leaking out -- drop by drop -- serves to lubricate the shaft and help the bearings and packings run cool. If you're regularly tightening up on the packing nuts then something is wrong and warrants further investigation.

The clearances between the shaft and housing along with shaft collars is only a few thousandths so there should be no measurable migration of fibers inside the cooling system. A possibility might be that your shaft is so badly worn with an excessive groove that fibers are then migrating.

The good news is that a worn water pump shaft can easily be turned down on a small lathe and a sleeve then fitted. The bad news is that if your engine is anything like my '22 Continental Red Seal 6, removing the shaft from the timing housing end is a nightmare.

[Rusty_OToole]

I had this problem recently on a 1951 DeSoto. When I took the rad out, turned it over and flushed it with a garden hose a massive amount of brown junk came out.

It appeared to be old kraft paper shop towels. The brown ones like a heavy duty J cloth.

A previous owner may have drained the rad for the winter and left the cap off. So a family of mice moved in and set up housekeeping.

The chewed up shop towels would make a gob the size of a football.

I also took off the water pump and cleaned out the block, but there was NO junk in the water pump or block. It all stayed in the rad.

So, you may have cotton waste in the top tank of the rad which is causing overheating. If so a thorough cleaning should fix it. You will probably have to take the rad off to get it all out. I know I tried to clean it without taking the rad off and only got about 1/10th what was in there.

I actually took the rad off so I could take the water pump off and inspect it and the inside of the block. But it turned out all the junk was in the rad anyway.