Overheating issues on the 73 440

[mattyj858]

 Hey guys, hoping to get some troubleshooting advice.


Coming home from camping this weekend my Winnebago started running hot,  which is uncommon for my vehicle. About a month ago I spotted a small pinhole leak in the lower end of my radiator near the fittings of the trainy cooler.  I follow the advice of the auto parts store and put in a copper based radiator stop leak. Haven't really driven the vehicle sense other than getting it up to operating temperature so the stop leak could circulate. Next trip out was last weekend,  ran fine to the campsite which is only about 5 miles away, but on the way back there was traffic and the temperature began to rise.


When I got home I immediately replaced the thermostat with a skirted 160°. I noticed the coolant was fairly orange and spots of copper when I drain the coolant
Once I installed the thermostat the vehicle ran hot again. Check the oil in the oil is clean.  The belts are intact and seem tight. This morning I started the motorhome with the radiator cap off,  it appears to me that there was no circulation of coolant when I look down the hall, seemed fairly calm.   If the radiator is unclogged and the pump is working correctly I should see a pretty turbulent flow of cool it down the radiator cap right? When I look down there it was completely calm and the coolant was  still green


Hoping you guys could give me some troubleshooting from here, money is tight and I know the best thing to do is pull the radiator and replace the water pump at the same time. I am weekend repair guy at best and think replacing the water pump by myself is a bit over my head.  I'm debating on replacing the upper and lower radiator hose as the next step of troubleshooting, I'm sure these things are old.
Before I start pulling things apart are there any other troubleshooting steps I should look at doing?


Last, if I do have to replace the water pump a friend mention that I possibly might be able to get out it without tearing apart the front end of the motor? How tough of a job is replacing pump for a hack like me?


Any help is greatly appreciated

[turbinebronze]

Hi Matty,
  Replacing the upper & lower hoses would be a good maintenance idem, but I doubt it will cure the problem(unless the lower hose is collapsing.) I've had a problem with the viscous drive fan on mine causing an overheating problem most all the time. The fan would freewheel when hot. With the engine hot and turned off, check and see if you can spin the fan. It should be very stiff to turn.
  Just my 2 cents, Craig.

[Rickf1985]

Do you remember the name of the stop leak? If it was a form of liquid glass that is bad stuff! That is what you use to seal a block leak or head gasket and sell it fast. I have only ever used Barr's Leaks and it has worked every single time. sometimes it will partially clog a heater core if the core is old and has deposits in it. This can be cleaned out by reverse flushing the core once the offending leak is fixed and the cooling system flushed of the stop leak.


Actually there is one other thing I have used with great success in the backwoods when four wheeling, eggs. Drop a couple raw eggs in the radiator and put the cap on. The downside is the smell a week later when you open it up!!! :)rotflmao :)rotflmao :)rotflmao :)rotflmao

[mattyj858]

Thanks, it was a Barr's radiator stop leak, the copper version.
The radiator is definitely old. dumb question but are you saying to reverse flush the radiator or the heater core? Will a clogged heater cause a rapid rise in temp?


How does one reverse flush? I found it interesting that it ran hot after I poured  that stuff in my radiator.


Thanks!

[legomybago]

You need a radiator my friend....When they start pin holing it's usually due to being rotten on the inside. And the water pump on a 440 is about the easiest one in the books to change. I wouldn't run a 160 thermostat either, too cool.

[Rickf1985]

Well, As Lego said, you need a radiator. The way stop leak works is that it finds areas where coolant is being forced through a small opening and it seals the small opening. The normal openings in a radiator are too big for stop leak to seal but a worn and clogged radiator will be a series of half clogged passages so the Barrs leaks seals off those passages because it sees them as leaks.
Reverse flushing a heater core is not hard. You take the hoses off between the heater valve and the core preferably at the valve and the engine so you do not put a strain on the tubes at the core and then you run water from a garden hose in the opposite direction that it normally flows from the engine. You will be amazed at all the crap that comes out. switch back and forth a few times and never use the full force of the hose, you do not want to put more than 12 lb.s of pressure on the core. Volume is the key thing here, a lot of water but not a lot of pressure. Just be aware that you are working with a 44 year old radiator core so it is possible that it may also have pin holes that will be uncovered when you flush it. And no, a clogged heater core will not affect the cooling of the engine. You can reverse flush the radiator the same way but it is pretty hard to do in the vehicle since the water has to go in the bottom and out the top.

[mattyj858]

 Thanks guys, I guess deep down I had a feeling that the radiator and the water pump need to be replaced. I will try reverse flushing it when I pull the radiator out of the vehicle. Question for you


If I reverse flush the radiator and water flows freely through the radiator out the top hose (water hose going into the lower hose, upside down and going out the top hose)  does that tell me that the radiator is OK provided I don't see any call leaks?
Also if I take the radiator to a radiator shop is a replacement fairly easy to get?. Thanks guys

[Rickf1985]

Just because water flows through it does not mean it is flowing through all of the tubes and a replacement is probably not going to be too hard to get but it will most likely be aluminum. Which is just fine. I put one in mine and it cools better than the copper one did. There is a reason they went to them in race cars, and price was not the reason. They also weight a LOT less! A radiator shop can take the top and bottom tanks off and tell you if it is any good. If it is good they can rod out the tubes and put the tanks back on and you are good to go. I tend to doubt that is going to be the case since you already have pinholes.

[mattyj858]

OK thanks for the info, last thing I want to do is replace the radiator and figure out how to modify it so it'll mount on the existing brackets

[postman]

Go to a radiator shop and have them pressure test. It could be something as simple as a radiator cap or as bad as cracked valve seats. Point being if the system will not maintain a pressure equal to that labeled on the radiator cap for 15mins you got problems. The science of it is hot water under pressure will excede 212 degrees prior to boiling. Water expands until it turns to steam.

[postman]

Visual Aid

https://www.youtube.com/watch?v=V7inC4lOpGs

[M & J]

He already said it had a pinhole leak.

[Rickf1985]

Hey guys, hoping to get some troubleshooting advice.





When I got home I immediately replaced the thermostat with a skirted 160°. I noticed the coolant was fairly orange and spots of copper when I drain the coolant
Once I installed the thermostat the vehicle ran hot again. Check the oil in the oil is clean.  The belts are intact and seem tight. This morning I started the motorhome with the radiator cap off,  it appears to me that there was no circulation of coolant when I look down the hall, seemed fairly calm.   If the radiator is unclogged and the pump is working correctly I should see a pretty turbulent flow of cool it down the radiator cap right? When I look down there it was completely calm and the coolant was  still green

If you started it and were looking for motion in the fluid right away then you would not see it because the thermostat was still closed. You will not see any fluid moving unless the thermostat is open. A 160 is way to cold of a thermostat, you need at least a 180. If it is overheating it is most likely not because of the thermostat and putting a colder one in keeps the engine from getting hot enough to vaporize the condensation that forms when it cools down, end result is water in the oil over time. And that nasty milky goo that forms under the oil cap and valve covers that you used to see in the 50's and 60's cars.

[postman]

Ooops sorry. Nevermind. orange and no circulation the vanes on the water pump may not be rusted out. But only if M&J likes that answer... W%  BUT what ever you do DO NOT inspect the Freeze plugs! :)rotflmao

[mattyj858]

Thanks guys for th info.


Yep didn't even think to warm the motor up for the thermostat to kick in. I'll try this again over the weekend. I opened the top cap and used a mirror to look in. Let's hope I see water flow.ill also check th lower hose to see if its hot. I know the lower hose is old.


As for orange water, I thinks it's a combination of rust and the copper Barrs stop leak. Whenever I inspected the coolant pre barrs stop leak and it was fairly green.


As for the pin hole leak, I was never able to trace it to its origin. I saw a small drip off one of the tranny cooler fittings, it was always green. It may be from the lower hose.


I checked the oil and there's no water/ chocolate milk.

[Rickf1985]

Postman, you would be much better received if you first read the entire thread and then made suggestions instead of snarky remarks. If the freeze plugs were leaking then he would see it under the engine and yes they probably should be inspected but that is not what is causing his overheating. the water pump impeller is a good suggestion but the way you worded it sort of turns people off. He will know once it warms up and the thermostat opens if it flows water the pump is good, if it doesn't then it could be bad.


Matty, is there a way you can see straight down into the radiator from the cap? IF so and there is not a baffle you will be able to see the coolant tubes and you will see pretty quickly if they are degraded.

[mattyj858]

Forgive me Rick, but I am learning as I go, that's why I love this site, lots of helpful people.


The only way I can look down the radiator is by taking a mirror and angling it over the inlet, but I get a pretty good view. Since I drained a bit of the copper orange coolant ( from the Barrs) and drove it back to the storage space, the coolant is pretty green and I don't see real rust issues with the inside. The radiator cap was clean and free of any rusty mud.


I'll revisit this weekend, and pray I don't have to take out the radiator, you guys scared me on this! I have taken a few out of trucks but never had to break off brackets... I don't weld and see a possible headache in my future..


Thanks and I will let you know how things go over the weekend, I am going to pull the lower hose which could quite possibly have a leak, collapsed or clog. I'll also replace the 160 for a 180 skirted thermostat.

[postman]

mattyj858
Best of luck! Found really great sources even one for aluminum...

[Rickf1985]

The brackets are soldered on but if you get an aluminum replacement then it would have to come with the brackets already mounted. The aluminum radiators have plastic tanks so are made differently. They are also substantially cheaper than a copper one if you could even find one. You can get yours recored but the guy that used to do all my radiator work stopped doing it because there are no more American cores to be had and the Chinese ones are junk, he refuses to use them. He just closed the radiator portion of his business.

[postman]

https://tinyurl.com/y7o6jyzs

W%

[postman]

If I forgot to mention...


Radiator Shop


                                                                           :)rotflmao

[mattyj858]

Thanks guys! I'll revisit over th weekend. Still hoping it might b something simple....

[postman]

mattyj858,


Thanks, you got me thinking. After the difficulty in locating valve cover gaskets (because of the wait) I am going to pull my bottom rad hose and order a new one. OZ. prevention># cure.

[postman]

mattyj found this morsel when browsing old threads.

http://www.classicwinnebagos.com/forum/index.php/topic,2933.0.html

[mattyj858]

 OK, I was able to get over to the Winnebago this morning and here's a couple notes


Got the motor up to operating temperature and was able to see water flow going through the radiator which is a good sign. I did notice some bubbles in the  coolant flow about the size of a pencil in diameter, is this normal?  After the motor ran for about 10 minutes it really didn't get much hotter than about 3/8  on the temp, which is odd because it rose rapidly last time I drove it. I let it idle in neutral for a solid 10 minutes and then I put it into drive with my foot on the brake to see if the temperature would rise but it stayed consistent.


The top hose was substantially hotter than the lower hose. [size=78%]The lower hose felt a bit spongy, and I will replace both top and bottom hoses along with changing the thermostat to a 180° and do a radiator flush treatment [/size]
A friend recommended I test the fan clutch by touching the fan under load with a rolled up newspaper, and the clutch seem fine it did not slow the fan down at all
I let about 12 to 14 ounces of coolant out from the petcock valve and the call it was a light green with copper flaking it from the barrs stop leak.  The coolant seem pretty darn deluded a very light lime green. I didn't see any rust or sediment in the bottom of the bucket.


After changing the upper and lower hoses, the thermostat and doing a radiator flush am I missing any other simple steps?
I'm wondering if I just had a temporary plug from that stop leak?


Any feedback is greatly appreciated! Thanks again for all your help