782 hydro leak

young enthusiest · #1 06-08-2010, 01:31 AM

I have a customers 782 in my shop right now, and the transmission was so covered in oil there was no air movment anywhere, it made quite a mess. Anyway, I cleaned it up, got it running, snd the leak is hiding but it's sure leaking. It's somewhere on the front of the transmissib, behind the brake lever (internal) I think. I'm not too sure really. I'm just wondering if anyone else has this problem, snd how hard it is to fix. It leaks about a cup an hour, and my 782 leaks too but much much slower. So if anyone knows what is involved in fixing this please speak up

TEET · #2 06-08-2010, 01:43 AM

I had a similar leak on my 1211, although it doesn't have internal brakes. It was really hard to find even after cleaning the whole pump and tranny. It ended up being the pump seal behind the trunnion. It would run down in a steady stream and drip off the bottom and left side of the tranny. It looked fine from up top, and appeared dry....but it was sure dumping a lot of hytran on my floor when it sat.

Not too bad to replace it, although disassembling the pump made me nervous..it went quite well and has been bone dry ever since.

Just an option for you to look at, as it seems a lot of folks have this leak, and it really looks like its leaking from a lower point on the tranny.

good luck,

Jeff (teet)

young enthusiest · #3 06-08-2010, 01:51 AM

Ok, so it sounds like it may be a challenge to fix, but I'm up to it

so I'll need to split the tractor then, and work on it from there I'm assuming. Did you need any special tools to work on the pump?

TEET · #4 06-08-2010, 02:12 AM

You may want to clean it really well first to ensure thats where yours is leaking from...you would hate to tear the pump apart if you didn't need to.

but...if it is..

You need to split the tractor, remove the charge pump...and definitely refer to the manual when it comes to pump disassembly. Its not hard, and requires no special tools,but can seem overwhelming. I made up a wood stand like the manual suggest to support the pump while its apart, and it worked well to keep all the "pistons"(if thats the right name) where they belong....and remember to keep everything CLEAN.

Also you need to very gently tap out roll pins on the shafts the hold the swashplate in...not hard, and not too far, because you can actually punch these through the side of the pump housing if you whack em too hard ...not good.

After its apart, the seal takes 10 seconds to replace, then the pump can be reassembled. It wasn't nearly as bad as I thought it would be.

Clean her up real good, and check it out real good to make sure this is where its leaking from...

Jeff (teet)

BCDSFCRET · #5 06-08-2010, 08:49 AM

The first thing I would do is remove the fenders then pressure wash the hydro pump.
Most of the time your leak will be the hydro relief valves. You can replace them or rebuild them.

Brian Dan.

young enthusiest · #6 06-08-2010, 09:05 AM

Jeff, thanks!!! Hopefully that's not the problem but if it is Im prepared now!
Brian, I've already done that, and from the top it is very clean now and I can't even see the leak. But from undereath on a creeper... That's when I start to see oil and dirt all over the place.man oh man was that thing ever dirty!

#7 06-08-2010, 09:16 AM

You don't have to 'split' the tractor if you don't want. Remove the filter, losen the pick up tube and turn down to the 2'oclock position, then un bold the 4 bolts, she comes right out.

If it's leaking below the pump it's the pump to case gasket, common.

Scott

Matt G. · #8 06-08-2010, 09:19 AM

If it's internal brake, the brake puck O-ring is probably shot. It usually leaks like crazy when it goes. You have to pull the rear and stand it up on end, remove the brake arm from the rear, and pull the brake puck out, replace the O-ring, and put it back together.

TEET · #9 06-08-2010, 09:25 AM

No problem Tyler. It can get frustrating trying to determine where the leak is coming from, but with some patience you can figure it out. My 1211 originally had a leak where the driveshaft connects to the pump...it would leak, and the fan would sling hytran everywhere. I assumed this was the only leak, but I was wrong.

Try to get it as dry as posible...put a piece of cardboard under the tractor to try and pinpoint where its dripping from, then you can try and trace it to the point of the leak. It took me a few days of wiping away the hytran on the lower front of my tranny, and carefully looking up at it with a flashlight to pin point my trunnion leak.

If you do find that the pump needs to come apart, you might better replace the rear seal, and the right side swashplate seal while your in there.

Also check the cork gasket between the pump and tranny...this is a notorious place for leaks as well, and a lot easier to fix then the trunnion seal.

I personally am weary of pressure washing too much when it comes to my tractors, as I really dont want to inject water at high pressure into places water wasn't meant to be...like pumps...might not be likely, but its possible.

Good luck,

Jeff (teet)

TEET · #10 06-08-2010, 09:28 AM

Quote:

Originally Posted by Matt G.

If it's internal brake, the brake puck O-ring is probably shot. It usually leaks like crazy when it goes. You have to pull the rear and stand it up on end, remove the brake arm from the rear, and pull the brake puck out, replace the O-ring, and put it back together.

Good info Matt...I have ZERO experience with internal brake trannys. Sounds like youve done it a few times

Jeff (teet)