# Perkins diesel leaking oil badly



## jturner (Jan 1, 2005)

Hello all. I need some help with AC 160 Perkins Diesel. I changed the head gasket, and tractor has been running fine for a month with no leaks. Today it starting leaking heavily. On the right rear of the block, there is a triangular flange bolted on, and on this flange is where the tachometer cable is connected. Below that connection on the flange there is a small hole (a weep hole???) and oil is pulsing out of that hole while the engine is running. What could be causing this?????? I did not disturb or remove this flange during head gasket teardown.


----------



## bontai Joe (Sep 16, 2003)

Crankcase breather dirty, causing excess pressure in the bowels of the motor?


----------



## Big Allis (Nov 24, 2003)

jturner can u remove flange for further inspection too see where oils coming from if it was the breather stopped up it be coming out the tube i believe


----------



## jturner (Jan 1, 2005)

Bontai, that was my first supsicion, but haven't found the clog.

BA, I will try that today to see what I can see.

Thanks.


----------



## jturner (Jan 1, 2005)

I have really found nothing today. Breather tube is completely unobstructed.

After a little surgery, I was able to remove the flange. Can't see a smoking gun. In the block there is a round shaft with a slot cut in the end that mates with a 90 deg. elbow that in turn mates with the Tach/hour cable. The elbow mounts on the triangular flange. In the flange there is this hole that the oil is pulsing out, so it sure looks as if there is an overpressure situation, but I don't understand why when the breather is clear. I'm stumped. What am I missing???


----------



## Big Allis (Nov 24, 2003)

jturner mght be O ring on end whwere cable goes in tht might be squirting oil


----------



## jturner (Jan 1, 2005)

Thanks, but the oil is not coming out of where the cable goes in. In the flange there is a hole, all the way through the flange, just below the protrusion where the shaft goes through the flange to connect to the elbow and cable. This hole is open to the inside where the shaft is driven. I can't really see what drives it specifically because I can't get behind it. It really seems that it's a vent hole which should only weep or in my case pulse oil if there is more pressure inside than there should be. I just can't figure out why there would be more pressure all of a sudden, when after the engine was put back together after head gasket failure/replacement, it's been working fine on a daily basis for weeks.


----------



## Live Oak (Dec 22, 2003)

Why did the head gasket go bad the first time? I hate to be the stick in the mud but this sure does sound like a blown or bad head gasket again.


----------



## jturner (Jan 1, 2005)

It's a 74 tractor and I guess it just happened. Head gasket perforated between the 2 and 3 cylinder and they filled with antifreeze and well, it didn't burn too good. After dissassembly, new gaskets everywhere I opened up, its been running great, and actually still does, but has this nagging oil problem all of a sudden.


----------



## Live Oak (Dec 22, 2003)

Was the head & block deck checked for square and trueness? If the head gasket failure previously caused an overheat; could be the the head is warped or cracked, similar situation with the block deck. The engine may run fine but it appears that compression is being lost somewhere. If you have the equipment; try a compression check to see if any one cylinder is below the others. A bad head gasket does not always result in oil in the coolant or vs. versa.


----------



## bontai Joe (Sep 16, 2003)

I think Chief may have found the answer. I can't think of anything else right now.


----------



## jturner (Jan 1, 2005)

The head/block were not checked professionally. The head gasket failure manifested itself I think fairly quickly. Engine was running then belched white smoke and died. Wouldn't restart. I towed it back to the barn. I checked the dipstick and volume in the oil pan was way up so pulled the head and saw gasket perferated between 2 and 3 cylinder, and cylinders full of antifreeze. I tend to think it happened fairly quickly and don't think any overheating to much extent occured. It has been suggested by another 160 owner that the flange has a seal behind it that will cause the weeping oil if the seal fails. I don't remember there being a seal behind it, but once this cold spell breaks, I'm going to pull it again, and see what I can see. Again. Thanks for the help guys.


----------



## Live Oak (Dec 22, 2003)

Sorry we couldn't be of more help. Good luck with it.


----------



## LHoegy (Mar 18, 2011)

*AC160 leak from Tach Adaptor*

I have the same problem.
Was there a happy ending to your story?


----------



## LHoegy (Mar 18, 2011)

Gentlemen,
Your scary stories of bad O-rings/warped heads/cracked blocks did not help the situation.
Perkins designed the flange with a weep hole so when the seal behind gives out, the oil will not run up the tach cable. Good Idea but messy.
I have replaced the seal (MF/Perkins Part # 37416751 and everything is good.


----------

