MF 135 cooling system issue

[bshadrake]

I am seeking suggestions, comments, recommendations, even questions on my 1972 MF 135 diesel tractor. Last summer while I was bushhoging the tractor blew a pin hole in the by pass hose from the water pump up to the thermostat housing. Hose was old so I replaced this hose. Few weeks later I was bus hogging again and this newly installed hose did the same thing, blew the by pass hose again. Installed all new hoses with a high quality hoses, which included a new by pass hose from the water pump to the thermostat housing. Kept a closer watch on the cooling system. It felt as though the thermostat was not opening up, the top of the radiator was getting to hot, couldn’t hardly touch it, upper radiator hoes was too hot, lower radiator hose was not hot or even warm to the touch. I removed and installed a new thermostat and reinstalled all the housing and hoses. Same issue. Then checked old thermostat in hot water, it was opening and closing properly. Went back in and removed thermostat,, for testing,, today there is not a thermostat in the thermostat housing, checked the radiator with a hose and made sure that the radiator was not stopped up and it is not, water flowed properly in and out of it, replaced the old water pump with a new water pump, without a thermostat the tractor seems to run properly, the top of the radiator stays warm, top radiator hose stays warm, bottom of the radiator is Luke warm and so is the bottom radiator hose. I’m starting to think that the antifreeze/coolant is not getting pumped through the lower block and through the head back in to the thermostat housing back to the radiator, I’m starting o think it is only getting pumped back through the by pass hose and over time of use the engine gets to hot and blows the by pass hose. How can I determine / see if the antifreeze/coolant is truly getting pumped from the radiator up through the water pump and through the lower block and into the head and back to the thermostat housing and back into the radiator?

 

[Jim.ME]

I am seeking suggestions, comments, recommendations, even questions on my 1972 MF 135 diesel tractor. Last summer while I was bushhoging the tractor blew a pin hole in the by pass hose from the water pump up to the thermostat housing. Hose was old so I replaced this hose. Few weeks later I was bus hogging again and this newly installed hose did the same thing, blew the by pass hose again. Installed all new hoses with a high quality hoses, which included a new by pass hose from the water pump to the thermostat housing. Kept a closer watch on the cooling system. It felt as though the thermostat was not opening up, the top of the radiator was getting to hot, couldn’t hardly touch it, upper radiator hoes was too hot, lower radiator hose was not hot or even warm to the touch. I removed and installed a new thermostat and reinstalled all the housing and hoses. Same issue. Then checked old thermostat in hot water, it was opening and closing properly. Went back in and removed thermostat,, for testing,, today there is not a thermostat in the thermostat housing, checked the radiator with a hose and made sure that the radiator was not stopped up and it is not, water flowed properly in and out of it, replaced the old water pump with a new water pump, without a thermostat the tractor seems to run properly, the top of the radiator stays warm, top radiator hose stays warm, bottom of the radiator is Luke warm and so is the bottom radiator hose. I’m starting to think that the antifreeze/coolant is not getting pumped through the lower block and through the head back in to the thermostat housing back to the radiator, I’m starting o think it is only getting pumped back through the by pass hose and over time of use the engine gets to hot and blows the by pass hose. How can I determine / see if the antifreeze/coolant is truly getting pumped from the radiator up through the water pump and through the lower block and into the head and back to the thermostat housing and back into the radiator?

What was the actual temperature while you were bush hogging? Your tractor should have a temperature gauge? Is it working? If not get one and install it as a first step. Diagnosing heating by what one feels is not worth much in my thoughts. Most people find 120 degrees uncomfortable, and 140 degrees is too much to touch. I believe your 135 diesel should have a 180-degree thermostat.

An infrared thermometer (temp Gun) is good to check the radiator with. Using one to scan the radiator core can show if coolant is flowing in narrow passages rather than across the entire core. It can also be used to check the block and head to see if it is fairly even in heating in all areas. It can pinpoint hot and cold spots, which gives you an idea of the flow path and possible blockages.

The hose between the water pump and thermostat housing is short, isn't it? Could the first replacement gotten damaged during installation, creating a weak spot in the hose?

Does your 135 have the radiator shroud in place around the fan?

 

[Dieseltech]

Check everything Jim said, the Perkins diesel does not run hot usually. I use a heat gun to check the hose temps, has it ever boiled over? Beast test the cap opening pressure too. With the sat out, coolant should be circulating quickly through the radiator with the cap off. If not there might be some coolant tubes plugged in the radiator, or the pump impeller damaged/broken inside.

 

[bshadrake]

I think that the temperature is off a bit but not that far off, it works and it was right around 170 to 180. the thermostat is a 180 degree one. both the old one and the new replacement one are 180 degrees. I do indeed have a good therometer gun, a good one !!! I will do that for sure. I will take the gun down to where the tractor is located and check these places on the tractor that you recomend and I will note the temps at these locations. The radiator is actually a brand new radiator,,, but i stilled check it to make sure it wasnt stopped up and to awsner your question it does have the proper shroud on the radiator.

the hose that you are asking about it is indeed that small short hose and yes, it is possible that it got damaged during installation because its hard place to get it into, yes its possible.

im looking forward to using the thermo gun to check for hot and cold spots on the head , block, and the radiator, and hoses. Thats a really great suggestion, thank you.

 

[bshadrake]

No the engine has never boiled over. I feel as though I have caught it before it ever got to that point. I have taken the radiator cap off and looked in the radiator and I can say that I dont see the coolant flowing, to me it looks like it sitting in there not moving through the radiator. The water pump is a new water pump and it looked good when I installed it. when I replaced the older water pump I was hoping that the old pump would have a broken impeller but it did not have any broken impeller or impeller parts. one thing that I did I opened up the block drain pet cock on the block and when i do coolant does come out with a good flow, so i know the coolant is getting into the lower block.

 

[mhankins]

Have you checked the radiator for combustion gases? A head gasket problem can build up a lot of pressure and cause that problem.

 

[used red MN]

the top of the radiator was getting to hot, couldn’t hardly touch it, upper radiator hoes was too hot, lower radiator hose was not hot or even warm to the touch.

I think you are just being over cautious. As Jim said 120F to your touch is generally very uncomfortable to most. At 140F most folk’s auto reflexes kick in and your hand jerks back. How the thermostat works, when it reaches its stamped set temp the thermostat opens a small amount and some hot coolant starts slowly passing through it. This heats up the top radiator hose because there is nothing to really cool that slow moving hot water. As the engine temperature rises more the thermostat opens more and flow increases pushing the hot coolant into the top of the radiator and it then flows down into the externally finned tubes where the fan draws air across it and cools it. So the coolant lower in the radiator may take quite some time to heat up especially if the small diesel engine is not working very hard. Put it all back together and use it keeping an eye on the temp gauge. If it doesn’t boil coolant out in my opinion everything is fine.

 

[hurleyjd]

Remove the radiator and take it to a radiator shop have it cleaned and rodded out. About the only thing you have not done.

 

[Jim.ME]

Remove the radiator and take it to a radiator shop have it cleaned and rodded out. About the only thing you have not done.

In post #4 he said, "The radiator is actually a brand new radiator".

 

[caterpillar guy]

Loose fan belt will let the fan slip and not cool well also. For new hose silicone hose is the place to go it is very flexible and last much longer than the common black hose used in the past.

 

[bshadrake]

I have taken the radiator cap off and looked into the radiator several times while the engine is running. I looked when the engine is cold and when it is warmed up to a good temp,, and I never see any air bubbles in the coolant inside of the radiator. I never have seen any white milky stuff inside of the radiator or in the coolant or any type of trash or bad smell , etc,,.. but I will keep looking inside of the radiator at the coolant.

 

[bshadrake]

as for the fan belt, that is another one that has throw up a red flag, thats a great point,, thanks, this tractor has been convertered from a generator to an alternator. it has a home made bracket that I do not like at all. its flemsime and some what weak. It currently uses a long fan belt for its belt. I am watching to see if i can see and slippage with the human eye but I do not see any. one of my top proiorities is to replace all of this bracket hardware with a better and stronger bracket. Im trying to pull up on the alternator in order to make sure its tight enough so that no sliipage is taking place.

 

[Jim.ME]

as for the fan belt, that is another one that has throw up a red flag, thats a great point,, thanks, this tractor has been convertered from a generator to an alternator. it has a home made bracket that I do not like at all. its flemsime and some what weak. It currently uses a long fan belt for its belt. I am watching to see if i can see and slippage with the human eye but I do not see any. one of my top proiorities is to replace all of this bracket hardware with a better and stronger bracket. Im trying to pull up on the alternator in order to make sure its tight enough so that no sliipage is taking place.

Is the pulley on the alternator width the same as the crank and water pump pulleys? I have seen people use the pulley an auto alternator comes with, often for about a 3/8" belt and then change to a belt width that fits the alternator pulley. If that was done the belt may be bottoming in the crank and water pump pulleys and slipping, even if it is tight. To fix such one needs to get a wider pulley for the alternator to match the OEM belt width and get back to the OEM width.

 

[DRJ]

Could the thermostat be in backwards?

 

[bshadrake]

I will check to make sure that the pulleys are all the proper width and to make sure that they all 3 pulleys have the belt sitting in the pulley correctly.

 

[bshadrake]

as of present time there is no thermostat installed in the thermostat housing. we did this in order to make sure that the flow of coolant was making its complete cycle through the system. I dont mind reinstalling the thermostat once I have confirm that the cooling system is working 100% properly. I want it reinstall it at some point so we can have the engine operating at the proper temperature for its best performance.

 

[BarnyardEngineering]

I'm having a little trouble identifying your concern here. The tractor is not overheating. Your observations about what is warm and what is not warm sound perfectly normal to me. The purpose of the radiator is to cool the coolant, and flow is top to bottom. The thermostat slows the flow of coolant so that it spends the maximum time in the radiator, being cooled. Taking the thermostat out lets the water shoot straight through so it spends minimal time in the radiator being cooled, and can often make an overheating problem worse.

I understand that you had bad luck with the first replacement hose, but has the bypass hose developed a pinhole since you've replaced everything?

What is it that you're trying to fix with all this troubleshooting and blasting away with the parts shotgun?

 

[bshadrake]

Thats correct, the tractor is not over heating as of present day. I have used the tractor a few times for over 10 to 30 minutes at a time the last few days. In fact through this entire process the engine/cooling system has never gotten over 200 degrees. Im a person that watches the gauges closely. From the first pin hole and through present moment it never has over heated. ( as in over 200 degrees ).

The new by pass hose has not developed a pin hole/leak after all of these parts were replaced.

The reason for the new radiator was because the old radiator had some leakage in a couple of seems. it was replaced as more of an upgrade while replacing all of the hoses, the old hose'es were looking very old and brittle. The water pump was the same scenario,, the water pump had a slow leak from it right behind the pulley where it went in to the pump so while I had the front of the engine exposed and easy to work on it I decided to replace it. I feel good about that replacement.

what I have been after is to find out if the coolant is actually getting pumped up through the lower block and into the head and then out through the thermostat housing back into the radiator. Other than running it for 20 to 30 minutes and it hasnt over heated and have no coolant leaks all looks like proper operation.

I have one of those laser temp readers. Im looking forward to using that device and see what the temps are from the top of the radiator, through the radiator, bottom of radiator, hose to water pump, the lower block area,, across the head, hose back to radiator.

Im trying to make sure its operating properly.

 

[504]

I am just guessing that the bypass hose nipple was painted. If it has been the paint is too slick and to hose blows off. I have seen it before,do not paint hose nipples. also make sure the clamp is about centered and not on the ends of the nipple.

 

[bshadrake]

Today was a big day. I went down to the farm and used the tractor for around one hour straight. I had the infrared red thermometer with me. Before starting the engine I took readings, the upper hose was 66 degrees, upper radiator 67 degrees, lower radiator hose was 67 degrees, lower block and head was around 66 to 67 degrees ( which looked good to me based on the fact the outside temperature was 65 degrees ). cranked up the tractor and ran it for 45 to 60 minutes, never did over heat,,, after finishing the work took tractor to the barn and checked temps, upper radiator hose was 99 to 100 degrees, upper radiator was around 98 to 100 degress, lower radiator hose was around 82 to 84 degrees, ( i like this temp drop, tells me that the fan is blowing some heat off of the coloant ) ,, then I used it on the lower block, hit the center of all 3 cylinders and got readings of 110 to 112 degrees , readings were bouncing between these numbers, then hit the head across it in various places and they were reading 112 to 114 degrees, then back at the upper radiator hose into the radiator.

I liked what I seen today with these readings and the fact that it ran for right at 60 minutes and did not over heat... going to run it a few more times and if all looks great I will then reinstall the new thermostat and check for proper engine temp and operation.