8011 Water in Oil

Greetings to all from a forum Newbie,

We've owned an 8011 for a few years now and its been a very reliable workhorse. However, we've now got a bit of a head scratcher....

Water has started to find its way into the sump. We first realised we had a problem when we had to add a gallon of water in a short space of time and found the oil had turned milky when the location of the leak wasn't obvious. The head gasket was changed, although the old one showed no signs of failure. All was fine again until the engine got to full temperature when baling hay and it started doing it again. This time we removed the sump and pressure tested the system, but couldnt find the leak. It seems like it only leaks when at full operating temperature. Anyone had this problem before or any ideas what it might be? The tractor has been running without the sump water jacket as it was thought that this could be porous somehow.

Thanks in advance

Try to replace the o rings at the bottom of the cylinder lines.

Yes! Cyl O ring is likely suspect, try some water stop-leak as i am sure you do not want to do another head-gasket unless you really have to.

Also.... Did you replace all the internal frost plugs? .... i think there may be some under the rocker cover on the Zetor...... common problem on many a car!

Had the same problem on a early 80's BS3D Mitsi 3 tonne bulldozer, after much head scratching, and a new head gasket, i discovered there was a set of (rusty) frost plugs in the tappet chest, only accessible once you removed the slightly larger outer frost plugs. and this was the source of the water in the sump!

Have also seen a cracked, or porous liner leak water into the sump ...... but only when hot! and stop leak will not work for long in this instance!

Maybe try another pressure test, but this time while the engine is still hot....... if you remove all but 4 bolts in the sump in advance, you will be able to get it off quicker
Disconnect the radiator and heater (if fitted) and pressure test the Engine only, that way you can crank the water pressure up to about 30psi and not worry about popping the radiator tanks

one more thing.... does your model have an oil cooler (water cooled) fitted ..... (other than the sump jacket)?
All the late 80's and early 90's Nissan's used a sandwich plate cooler under the spin on filter, and i have had a couple of them leak ...... but usually more oil into the water than the other way around.

Many thanks indeed for the advice. I will update this post as we make progress on this problem.