790 Rear end leak??? What the heck is this???

790guy · Feb 19, 2006

Just got done Blowing the snow off my drive, a 11 below zero what fun here in Wisconsin. I noticed red fluid under the machine while idling. I crawled underneath and noticed 2 tapped holes on each side without a plug in either. this is near the front of the rear end near the brake covers. I seems that these fine tapped holes should have a plug???

Fluid was dripping from both sides??? HELP???????

RoyJackson · Feb 19, 2006

I went into the garage and crawled under my 790. I didn't see any threaded holes with (or without) plugs or bolts. No plastic caps (as you would see in a vent hole) at all.

The red fluid is definitely hydraulic fluid.

I'm assuming by now, you've checked the transmission/hydraulics fluid levels. Was that at the level it should be? If so, I don't think I'd get too excited. They're probably vents of some sort...

How large are these holes (quarter inch in diameter or smaller)?

790guy · Feb 19, 2006

I was hoping for your reply! The transaxle still ok according to the dip stick. The roughly 1/8 tap holes are in the area of the brake rods going to the diff. the are about in a horizontal position but low on the drum circle. there has to be a plug of some sort. to keep dirt out. There is a flat boss that they are both in??? The brakes are dry design, are the seals leaking into the brake drum area? Are these drains in case they leak. it was 11 below zero did the axle shrink slightly causing a leak in the seal area and did the plugs both vibrate out?

Something is flakey here, what are the odds of both plugs comming unscrewed????

Thanks for looking Roy!!! I appreciate your going out and looking!!! Any other Ideas Roy?????

deerehoe · Feb 19, 2006

my 770 which is the same as your 790 has two threaded holes. The brakes on my are dry and they sqeak sometimes if you have oil coming out them it would make the brakes work funny? just aidea

RobS · Feb 19, 2006

I've seen the same holes on my 790 but never any fluid leaking from them. They might be vent holes for the dry brake area. If there is fluid you may have a seal leak from the transmission into the brake. The transmission/rearend shares the same fluid as the hydraulic system.

Might have been related to the cold but there also may be some sort of permanent damage to the seals. I'd watch it for a while and if it continues check further. How new is your machine? Warranty?

/forums/images/graemlins/smile.gif

RoyJackson · Feb 20, 2006

"I've seen the same holes on my 790 but never any fluid leaking from them."

Do those holes have caps of any sort in them, Rob?

I'll take a closer lok when I get home tonight...now that I know the size (.12" or ~ 3mm), I'll have a better idea of what I'm looking for.

I've never had any leakage under my 790. However, the cold weather (11° was written, I believe), shrinking seals is a definite possibility).

RobS · Feb 20, 2006

Nope, no caps. I can't remember exactly where the holes are but I did make the same observation when I first got my tractor... "What are those and shouldn't they have caps?". I think I checked the parts manual and it doesn't show anything /forums/images/graemlins/smile.gif

790guy · Feb 20, 2006

I took a pic of the holes.. the Deere dealer had no idea whatsoever. any ideas if these have plugs???

I will try to add pic

790guy · Feb 20, 2006

I cannot get the file to compress, Hey Roy can you take one more look? It's near the brake rods in the diff housing. I called 2 JD Dealers with no help. I can't understand why they cannot answer the question. It sounds like the 770 has no plugs. can anyone else take a peek. do any JD dealers look at this awesome site. It's gonna snow more and I dont want to trash my trans-diff case???

RoyJackson · Feb 20, 2006

I did get back under the tractor and took another look...

Yep, there are two threaded holes as you described.

They are also shown in the Deere workshop manual for the 670/770/790 tractor in the Final Drive/Axle section...no plugs there either, but are quite clearly drilled and tapped. See the attached picture. The holes in question are almost exactly centered in the picture...note that there are no caps.

There is no explanation of what these holes do (but I didn't scan all 1008 pages of the manual). They may have been used in the manufacturing processes, but my guess is they are an overflow hole.

Again, I wouldn't worry about them unless you see more leakage or your brakes don't operate correctly