I bought an old Case 780 2 months ago.Found out the radiator leaked and the brakes dont work.The compressor belt was missing and the mount was messed up.Got that figured out and done.The master cylinders were dry, machine sat for some time. Engi9ne is good. Refilled the master cylinders and see a drip on one wheel.Tried to bleed brakes and had to screw the bleeder all the way out to get drippage.The brake actuators at the masters are working with the air running but still no brakes. I cat pull wheel now I put some hydraulic fluid stop leak in the line thats dripping. Im going to try to adjust the brakes at the wheels.The emergency brakes not working either.Is there any way to tell if the linings are good?
The master cylinders may need overhauling. The wheel cylinders prolly needs to be repaired or replaced. You would need to remove the tires and the brake drums to inspect the linings. Did shorten the parking brake adjuster to try and get it to actuate the brake ? It may have a control valve not functioning if it has one. Stop leak in hydraulic fluid is a waste of money. The only way I know to fix a brake line thats leaking is replace it. Or if it is a steel line you could cut out the rotten section and splice in a new piece.
I havent shortened parking brake adjuster yet. I will Thanks for your reply. Jim
In case you aren't aware, CNH has the parts book for your 780 online-> HERE .
Ok, cant find shoes for this Case 780- Part# L33102 superseded by N9261 Did order wheel cylinder rebuild kits $75.00 each from Groff equipment here in PA I tried Broken tractor and 5 other case dealers . Does anyone have a source for the shoes? And Tinkerer i have the parts book and original service manual. Thanks
It is good you already have those books. They are invaluable. Especially the parts book. CNH has dropped a lot of the obsolete parts numbers from their stupid online parts book. Start looking for a brake shop that will reline them. I am quite sure any heavy truck repair shop can fix you up.
ok got the right rear wheel off. There is a 3 1/2" nut holding in the bearings. Didnt have that size so chiseled it around and off. I underdstand the torgue on that is very important so that you dont squeeze the bearings down. Anyone know the torque on that? Or the number of revolutions to tighten it. The brake linings have a lot of meat on them, one wheel cylinder leaks so i got rebuild kit for both wheel cylinders. One of the wheel cylinders leaked so i cleaned off the lining with oven cleaner and roughed them up with 100 grit paper. Im glad i dont have to get new shoes because the only place that had them is Southern Equipment and that was $320 apiece. Been dealing with Groff tractor here in PA for parts for the machine.
Hello Again, worked on both rear wheels,removed planeteries,put in new wheel cylinders and cleaned up the brake shoes, one side was wet with oil from a leaking axle seal, got a new one put it in. I am having a very hard time adjusting these .Anyone know how to turn the star wheels to expand the shoes? is there a trick to it. And i also vacuum bled them, but in book says pressure bleed them, is perssure bleeding necessary. The air brake actuators are working and air pressure is 120. Just cant get it to stop well.Thanks for any advice you can give Jim
I have never worked on a 780 with that style of adjuster. So, I can't give any advice there. Hydraulic brake systems always need to be bled after opening them for service. Pressure bleeding is a good way to do it, but I have done quite a few by depressing the pedals.
Thanks tinkerer I found that the brake adjustment handle should go toward the axle to expand
Is the tractor stopping better now ? I can slide the rear tires on my 680. It has air brakes with no hydraulics involved.
havent found out yet Just adjusted shoes .It was very cold here and batteries dead so i gotta get it started to see how the brakes are. will do in a couple of days
Ok looks like the master cylinders are at fault, no real fluid pressure when applying brakes.I am now looking for part numbers for the master cylinders ,or rebuild kits ,Case no longer has them. So i am trying for Bendix part numbers
A Mr Fletcher on this forum told me that he used these master cylinders. https://www.partsgeek.com/9kzhq7w-studebaker-champion-brake-master-cylinder.html so im going to buy two of them, price is right
Wonder if those would work on my 680?
dont know, but if you try to order them it asks what year and i need for Mr Fletcher to tell me that if he remembers
Alert!! I pulled my master cylinders today and they are Wagner FD 8832 Disregard what i said about Raybestos. I looked up the Wagner part # and found they were also used in forklifts. So im buying 2 of them from a forklift supply house for $43 apiece.
Ok im waiting for parts, 2 master cyls and 2 diaphragms for air cans( they are for M48 army trucks) but i found lot of oil in the air canisters i knowit must be from compressor leakage I am wondering if i have enough air pressure to squeeze the master cylinders. Going to try mount a pressure gauge on each air line at the air canisters.
Replaced the 2 masters and i have brakes again
Thanks for posting your findings. It will surely help someone else with the similar problems.
I am working on a case 780, pulled brake chambers and master cylinders one of which was dry. Sound familiar? I am waiting for my FD-8832 masters to arrive tomorrow. Can you give me some details on pulling the wheel and brake drum to see if wheel cylinder is leaking. Also where did you get the rebuild kits and part numbers for the wheel cylinders? Thanks for any help that you could give!
James Madigan hasn't logged in since last May. I doubt that he will read this anytime soon. Try sending him a Private Message. HEF will create and send him an email that he has a PM here.
I got the wheel cylinder kits from Case about $75 apiece. To pull the wheel and get to brake drum you need to take off the planetary gear sets. If you have a manual it will tell you how. If not let me know maybe i can get you some manual pages covering it.Its a job but not the worst.
James Madigan, you are a champ. Cool that you shared your fix-up process and then came back online to help the latest fellow out.
Thanks Gary. I got a ? anyone know about the loader Hydraulic Main Relief valve.Mine leaks at different times, sometimes after i shut the machine down. Sometimes when im operating for awhile.
The parts book will reveal most of what you need to know. Be very careful about not changing the setting adjuster if you take the valve apart.
this is the one im talking about https://imgur.com/a/wCT2l8s
Your service manual is showing it in the valve body to explain the flow paths of it. I don't know what model or production year your 780 was made. So, it is not possible for me to offer you any more help. You need to find the correct parts book for your machine if you want to get the "O" rings that are leaking.
Ok new problem i have hydraulic oil leaking into trans.I had heard they are 2 seperate systems.I did replace radiator a while back, could it be a switched hose to oil cooler.
No, the oil cooler would flow enough to empty the system in minutes. Is brakes a possibility for hydraulics leaking to the transmission?
I cant see how.
The hydraulic pump is mounted to the back of the transmission - there will be a shaft seal at front of the pump that will need looking at.
Thank you ALR i thought that was the problem.