550 Brake Question

[Tom Sanderson]

1965 550 Gas with approx 2000 hrs, has a Oliver 1550 front end loader

While I was learning how to use my power rake, I got fed-up with the left brake always sticking/dragging. Tore brake assemblies off to rebuild. Decided to fix some of the rear-end leaks also so I replaced both brake thru shaft lip seals and both rear axle seals. Lessons Learned, don’t use 10W30 oil in transmission as they recommend as it will all leak out. I used 80W90 even after I replaced 4 of the 6 rear-end lip seals.

I fought big time to remove the brake pack assemblies due to excessive corrosion on brake shaft splines. My splines have excessive wear and I just cleaned them up best I could by stroking a wire wheel on a 4” grinder axially to remove all the rust. Mice made nest inside the housing and I believe caused the severe corrosion. I cleaned everything else up really good, replaced all the brake balls, 4 springs, and put it all back together after replacing the seals. Oh yeah, I screwed up and busted the inner pressure plate on left side by over torquing 3 5/8” bolts. Kudos goes to Pell’s Farm Equipment in MI as they were lifesaver. They had a used one for the LS that was reasonably priced. I definitely recommend them for Oliver parts.

Finally my question: Everything works fine except, the left brake still seems to settle in to a dragging position, almost like a detent. I’m wondering if my spline wear on that side was bad enough that at least one of the splined disk is still catching and the return spring isn’t strong enough to overcome it? Difference now is that it will easily reset just by nudging the back side of the brake peddle. Is there any other reasons that might cause the LS brake to hang-up???

 

[rrlund]

You say it'll release by nudging the back side of the pedal. Is the return spring stiff enough to pull it back up on its own? Also,those balls in the actuator,it's a good idea to put a little powdered graphite on those.

 

[Tom Sanderson]

Too late for the powdered graphite suggestion as I used a light coat of moly grease with a little bit of anti-seize added, but Thx anyway. I really needed something to help prevent the corrosion from taking hold again. Regarding the spring tension, the shortest (strongest) spring is now on the LH side. I believe they are the opposite of where they were originally installed under the pedals. That would make sense that the RS is now on the LS and vice versa as the LS brake always gets used twice as much as the RS. Besides that, I also increased the angle of the floor board tabs by bending them slightly where the springs connect giving me additional spring tension. The result is the RS brake works just fine with no hang-ups. I guess that one always worked fine which is surprising considering the condition at teardown, all four springs on the reactor plate assemblies were broke. I just thought of something, I need to play with it some more to confirm the LS will hang up when the tractor is rolling, then watch the pedal after the tractor stops to see if the LS brake will release. If it does, this would confirm that the poor condition of the splines where they engage with the rotors on the LS are causing them to hang up. During rotation, the splines are rough and will catch on the rotor spline, but then releases when the torsional load goes to zero (i.e. when tractor stops rolling). Zero tractor speed (rotor rotation) allows the rotors to slide easier on the spline without catching? Again, it’s only the LS that hangs up. I could replace the LS return spring with a new one to see if that helps too I guess? Sorry for bad case of mouth diarrhea.

 

[rrlund]

No problem. You must be farily close to me if you deal with Pells. I deal with Hofferberts. They're just a little bit closer to me,but in the other direction. Both were Oliver dealers back in the day though.

 

[Thompson Mike]

This may be way off from your problem however it happened to me on two different 55/550's. The new disc's were too thick so when it was all torqued down the brake basically locked up once in awhile. If I loosened the bolts just a bit it worked great. So I ended up taking the disc out and sanding down just a little bit of surface on each disc and reassembled. Problem fixed.

 

[Tom Sanderson]

Nope, that can't be the case here. Even though the brake disks (rotors) weren't in the best of shape, I reused all four of them. I was too cheap to spend the ~$125 for a new set.

 

[J.Mash]

Over tightening the drum bolts, (especially the three in the middle) will cause your problem.It distorts the drum, and causes brake drag. I learned this the hard way. Make sure you have correct travel on your pedals(at least 2 or more inches) and good return springs.The expander springs must be good and never have been over heated. Free travel on the pedals will decrease as the brakes heat up. Get that grease,anti-seize out of there and use graphite or slip-plate or you will have trouble with brake dust sticking to everything.

 

[Tom Sanderson]

Thx for the advice. I'll double check the torque on the 3 bolts, but was very careful after overtorquing and ruining one pressure plate already. I agree with your thought on having 2" of pedal travel versus the 1" I currently have to see if that helps and will try that next. On the slip plate, isn't that a grease too?

 

[Don-Wi]

Powdered graphite is what you want in there. Slip plate is basically a graphite paint that is used in gravity boxes and the like. The powdered graphite doesn't attract brake dust to make a gummy mess in there, which will make your brakes stick.

I don't see that you mention replacing the springs and balls in there, but if you didn't I would highly recommend it. Polish the ramps, use new balls and springs, and put powdered graphite in there. Should make a difference if you haven't done it already.

As far as you comment about not using 10W-30, they had an additive that you would have put in with that oil back in the day, but that is no longer available. 80w-90 is the correct oil to run with todays oils.

Donovan from Wisconsin

 

[sparky7]

Do you happen to remember the size of the shaft seals for the brakes?

 

[J.Mash]

The slip plate i have dries hard like paint. Graphite will do just fine, you may have to brush it on with a small brush to get it to stay on good. Just be sure every working part is clean of rust. There is a torque spec for those bolts,(Its not much) but what you want to is just flatten out those lock washers and no more.Keep a check on those bolts. If they get loose on you ,use some blue lock-tite on the threads. One more very important thing, is to put the parking brakes on when not using the tractor.This will keep the expanders and drums from getting rusty, and making the brakes grab and stick. The 550 owners manual says to store tractor with parking brakes on. They will get rust on them almost over night. If the brake discs ever get over heated, they are never the same. If the pedals get too far out of adjustment, it weakens the expander springs.I like to keep my pedal travel about half way down when brakes are cold.While i am backing our tractors out of the shed i lightly ride the brakes a few feet while in reverse to clean them up. These are the things i do with our 550's. No more brake troubles.

 

[Anonymous-0]

The brake thru shaft is a approx 1 inch dia shaft as I recall. I thought of going to a generic lip seal too, but errored on the cautious side and went through the AGCO dealer for all the new parts I used. If this was a hobby, it would be an expensive one.

 

[Tom Sanderson]

All sound like good tips from a seasoned user, Thx Again!

 

[sparky7]

Do you have a website for AGCO, i tried looking theres a few companys that use those letters and i couldnt find it.

 

[Tom Sanderson]

http://www.agcoparts.com/
Then go to bottom of page and enter your zip code, this dealer locator worked good for me.