780 brake drum

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780 brake drum

Post by bengentry6 » Sun May 17, 2020 11:01 am

Hi All,

After finally getting round to changing the brakes on my 780, I took the final reductions off to discover that the left hand brake pads weren't actually worn down but the oil seal had broken, allowing oil to fill the brake drum, shown in the photo.

So the next job is to remove the brake drum to replace the oil seal behind it which I understand can be a tricky task without a proper puller.

I have a rough idea of how to make a puller, but before I do that, is there anyone on here that has made one previously that might be able to lend it to me for a short period of time? Or has any tips on making one?

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Re: 780 brake drum

Post by cobbadog » Sun May 17, 2020 12:49 pm

The good news is that you dont have to remove the brake drum from the axle. Buy a new set of linings so that you can start with good dry linings. Some just use brake kleen product but for the coat of new linings and 30 minutes work replace them and you will also find that the new linings are softer than the old linings and will grip far better. I made my puller/s to do this job and I was advised to buy a pair of new seals to put in place as there is room for 2 seals and will sit on a new surface for a better seal. I went one step further and bought speedi-seals for the axle surface so that it has a brand new surface to run on. The final thing you need to remove to get the old seal out is some BSF bolts, 1/4" I think from memory and wind them into that cover. The cover that is removed can stay off to allow room for the 2 seals. I also put speedi-sleeves on the half shafts in the reduction box along with new seals and then I did the other side. Now when unloading the tractor from Lorry the truck I can easily control the speed at which the tractor rolls down the ramps with these new linings.

Did you strip down the reduction box or remove the housing as a complete unit?

Also be carefull on re-assembly. One side of mine went straight back together with no issues but the other side would engage the axle into the diff centre and then slide almost all the way in then lock up. I had this side in and out at least 20 times before it finally went all the way in. Why this happened I have no idea so be patient.

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Re: 780 brake drum

Post by ollek » Sun May 17, 2020 1:17 pm

Here we are again, compering an 30C with a Selectamatic. If the oil leak is from the rear axle, then you change the two seals per side in the rear axle. The seals are in seal housings. ALL Implematic and Selectamatic tractors have two seals per side in this location from the factory. The one seal system is ONLY in tractors older than Implematic. If the leak is from the wheel reduction, then you have to remove the brake drum. The following link shows the seal setup in the rear axle and the seal housing ref 38 has to be removed before the seals, ref 39 can be changed https://partstore.caseih.com/us/parts-s ... 03ar490594 and the following link is for the wheel reduction and the seal is ref 4 https://partstore.caseih.com/us/parts-s ... 03ar256244 The following link takes you to the complete workshop manual for your tractor, just select the section you need https://drive.google.com/drive/folders/ ... Dh6M2k0bVk Section K TRANSMISSION is about the wheel reduction and the rear axle seal. Important! If you remove the right hand side wheel reduction, press the diff lock pedal fully down and tighten the pedal in this position before you remove teh unite. If not done, then the diff lock sleve and spring vill drop down into the rear axle.

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