8N Water Pump Woes - No option now but to replace it

I'd been running this tractor for a while with cooling issues. I've never replaced the water pump and this tractor has been in use since 1998. So there is no record of how old the water pump may be. The symptoms of cooling problems are the radiator would blow steam after about 15 minutes then it would magically stop and then it started steaming again. The tractor was running very hot as evidenced by the gas tank producing a 'boiling' sound. Also the heat from the engine was noticeable to the operator. Any debris like leaves or brush clippings that reached the exhaust manifold would begin to smolder. I even had a very small fire start on the exhaust manifold a while back. Yes I was incredibly lucky and am thankful the tractor didn't go up in flames or explode from gas vapors escaping the extremely hot gas tank.

This past weekend the tell-tale sound of a bad water pump was there when I started the machine. Squealing and squeaking from the front near the radiator. I ran the machine and sometimes it would steam from the radiator and sometimes it would not. A lot of it depended on how much throttle I gave it. The radiator was not overfilled but I did suspect that the belt was loose.

In an attempt to correct the problem of squealing and squeaking, I did tighten up the belt. The 1/2 inch of play was much greater than 1/2 inch and more like 3/4 of an inch or more. This adjustment was proably not the worst of ideas but in hindsight, not the best either. I think I over tightened the fan belt and put stress on the water pump. However, the tractor ran fine and the radiator steaming stopped temporarily. What I did find was once the radiator started steaming again, there was a much bigger problem. I could visibly see coolant blown onto the engine from the radiator fan.

I took the machine back to the barn, left it running on idle and saw that the water pump had most likely failed somewhere. It appeared that the lower radiator hose was leaking. In my experience though, usually a radiator hose will just fail completely and dump all the coolant within a matter of seconds. I did squeeze the hose and doing so did not worsen any potential hole or tear. The hose was quite spongy and flexible though.

When I turned the tractor off I noticed that coolant was coming out of the pump towards the front of it where the fan attaches to the pulley. I'd been looking for any sign of coolant from the weep hole but never could find anything. When it cooled off, I checked the radiator and the fluid level was very low but this didn't surprise me due to the leak.

At this point I think I not only need to replace the water pump but also both coolant hoses, thermostat, and fluid to get to a place where I can determine if there are other issues with the cooling system.

As a final thought, I am wondering if the timing of the distributor is off. This is a front mount distributor I replaced 2 years ago. I had set the points on it but never looked at the timing to see if it was correct.
 
(quoted from post at 14:36:10 11/21/18) I'd been running this tractor for a while with cooling issues. I've never replaced the water pump and this tractor has been in use since 1998. So there is no record of how old the water pump may be. The symptoms of cooling problems are the radiator would blow steam after about 15 minutes then it would magically stop and then it started steaming again. The tractor was running very hot as evidenced by the gas tank producing a 'boiling' sound. Also the heat from the engine was noticeable to the operator. Any debris like leaves or brush clippings that reached the exhaust manifold would begin to smolder. I even had a very small fire start on the exhaust manifold a while back. Yes I was incredibly lucky and am thankful the tractor didn't go up in flames or explode from gas vapors escaping the extremely hot gas tank.

This past weekend the tell-tale sound of a bad water pump was there when I started the machine. Squealing and squeaking from the front near the radiator. I ran the machine and sometimes it would steam from the radiator and sometimes it would not. A lot of it depended on how much throttle I gave it. The radiator was not overfilled but I did suspect that the belt was loose.

In an attempt to correct the problem of squealing and squeaking, I did tighten up the belt. The 1/2 inch of play was much greater than 1/2 inch and more like 3/4 of an inch or more. This adjustment was proably not the worst of ideas but in hindsight, not the best either. I think I over tightened the fan belt and put stress on the water pump. However, the tractor ran fine and the radiator steaming stopped temporarily. What I did find was once the radiator started steaming again, there was a much bigger problem. I could visibly see coolant blown onto the engine from the radiator fan.

I took the machine back to the barn, left it running on idle and saw that the water pump had most likely failed somewhere. It appeared that the lower radiator hose was leaking. In my experience though, usually a radiator hose will just fail completely and dump all the coolant within a matter of seconds. I did squeeze the hose and doing so did not worsen any potential hole or tear. The hose was quite spongy and flexible though.

When I turned the tractor off I noticed that coolant was coming out of the pump towards the front of it where the fan attaches to the pulley. I'd been looking for any sign of coolant from the weep hole but never could find anything. When it cooled off, I checked the radiator and the fluid level was very low but this didn't surprise me due to the leak.

At this point I think I not only need to replace the water pump but also both coolant hoses, thermostat, and fluid to get to a place where I can determine if there are other issues with the cooling system.

As a final thought, I am wondering if the timing of the distributor is off. This is a front mount distributor I replaced 2 years ago. I had set the points on it but never looked at the timing to see if it was correct.
ate or retarded timing will make engine run hot. Either static or centrifugal.
 
As JMOR says, retarded timing (again, either static or centrifugal) will cause the exhaust to run hot but is sounds like you have more problems.

Does your tractor have a fan shroud. If not it needs one.

People have been known to replace the water pump on an 8N without removing the hood and radiator (no fan shroud) but I certainly would not recommend doing so.

Since you need to remove the hood to replace the water pump and probably install a fan shroud, you should remove the radiator while the hood is off (Makes replacing the radiator (fan shroud or not) MUCH easier) and take it to a GOOD radiator shop for cleaning, testing and leak repair. You will be glad that you did in the foreseeable future.

If possible, get a rebuilt OEM water pump rather than a new aftermarket one. Again, you will be glad that you did. Try NAPA, do not go to the young kid at the counter, and be specific. I was able to get a rebuilt OEM pump at NAPA when I last changed one but it was the only one in the Chicago warehouse at the time and this has been several years. Good luck.

Re-torque the cylinder head.

Final thought: If your radiator shop tells that you need a new radiator, you can take your chances with an aftermarket one or contact me for a good OEM one (you know, the ones that fit) just back from my good radiator shop.

Again, good luck.

Dean
 
I replaced the water pump on a 2N without removing anything else. If I had it to do over, I think I would take the hood off first.

I used a new pump from YT. The only problem I had was that the base on the new pump was thicker than OEM -- just enough to make the studs in the block too short. Local auto parts store had the right studs in stock -- just enough longer than OEM to work.
 
Thank you guys and I appreciate the excellent wisdom and advice. I am fairly certain (95%) there is a fan shroud when I compare my 8N with pictures on the Internet.

I'll need to check on the radiator itself. I'm hoping the leak is only the water pump but if it is the radiator I'll be in touch. I've read that aftermarket radiators do not fit. I've also read that the OEM radiators were built better than the aftermarket ones.

I know the I&T manual doesn't explicitly state in the paragraph for water pump removal that the hood needs to come off. But I did see that in the paragraph before the water pump removal the manual states how to remove the hood. In my mind there is a subtle hint that the mechanic (DIY or professional) should remove the hood when working on the cooling system. Plus, no one wants to damage the radiator fins or bust knuckles working on the tractor. Removing the hood seems to be a good idea for access and the job doesn't look like it is difficult. The time spent removing the hood will be made up by the speed of replacing the water pump when the hood is out of the way.

I'd never thought of checking the head bolts as well with the hood off. I'll add that to the check list of things when I dig into the project. I'm thinking that a full day of work is the best plan for the job. No need to rush anything either. Do it once and do it right is the way I will proceed.
 
Bingo!

Tough (no, I did not say impossible) to replace the OEM studs with longer studs without removing the hood and radiator and shroud.

Dean
 
Are you using a thermostat correctly installed? That plus a fan shroud are essential to a good, correct cooling operation. You do need to remove the hood to replace the radiator but not necessary to replace the water pump. It does help to have the hood off and everything right there to work on. In my case, I had no choice on my 8N as my fan came loose from an aftermarket pump and spun into the radiator so I had to replace both. There are water pump rebuild kits too and I opt to always rebuild an OEM part over buying anything 'new' -my previous encounters (for one, as described) with aftermarket parts has been dismal. If the water pump is making an noise, the bearing is shot, I'd fix it now.

Tim *PloughNman* Daley(MI)
 

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