5511 brake bands and shoes

[davew]

Hi - I ordered shoes and brake bands for my 5511 and the ones supplied are the same size as my old ones removed from the 3545. Is this correct - I plan to strip and replace the brake parts at the weekend but dont want to find out then I have the wrong parts.

Thanks

 

[Renze]

no, the 3011, 3511 and 4712 had smaller diameter brakes.

 

[davew]

Thanks

I spoke with the supplier today and he confirmed the part numbers from his parts manual and that the 5511 has a smaller drum than the other 4 cylinders but has the larger spline. Will find out for sure at the weekend.

 

[alan]

Hi your supplier is correct

 

[Renze]

Hi your supplier is correct

Then i ordered the wrong shoes for the 5511 as well.. nevermind, they DO fit the 5718.. I assumed them to be the same on all four cylinders because the differentials are pretty much the same for decades...
Assumption is the mother of all f*ck ups

 

[davew]

Have not got the brakes apart yet due to harvest but noticed today that some oil has leaked out of the left axle shaft on to the wheel centre disc and rim. Is this a common problem. Oil level in final drive is not above the fill plug. Is it worth changing this seal when i have the portal off. Is it straight forward to change. Thanks

 

[Renze]

I order the oil seal when i order the brakes. When fiddling the driveshaft back into the differential, you have a 50% chance the very old seal starts leaking because you overstretch it while putting the halfshaft back in.

 

[davew]

I have new seals for the shafts that go into the differential (i replaced them on the 3545 when i redid the brakes) but this leak is coming from the shaft that comes out from the bull gear. I'll try to get a photo today. Thanks

 

[Renze]

I have never had one of them leaking, but according to the manual its just another Gufero seal.

 

[davew]

Thanks - The leak is minimal so I decided to leave this seal for now as I need to get the tractor going again this week. The left brake was sticking on and thought this was due to seized pivot pins but problems seems to be a stuck piston in the slave cylinder. The cylinder looks fairly new and not corroded but one piston is stuck fast. All the parts sent were correct and once i do a weld repair on the mud gaurd it should be up and running soon.

 

[hve]

stuck piston in the slave cylinder. The cylinder looks fairly new and not corroded but one piston is stuck fast.

Was a common problem on old drum brake cars and trucks too, lack of use is the biggest problem, when you put it together use "rubberlube" (special grease for rubber) to assemble the piston back in the slave cylinder (use plenty) this will stop the piston from sticking again, and double the life of the seals

 

[davew]

Thanks for the info. I fitted a new slave cylinder and portals are back on but will consider this in future. I bled the brakes but when i press the pedals independantly they both go to the stop and shoes just make contact however if i press both pedals together the brakes are good with pedals only going about 1/2 way down. Anyone seen this before?

 

[Renze]

Thanks for the info. I fitted a new slave cylinder and portals are back on but will consider this in future. I bled the brakes but when i press the pedals independantly they both go to the stop and shoes just make contact however if i press both pedals together the brakes are good with pedals only going about 1/2 way down. Anyone seen this before?

No, never had that before, but perhaps anyone else can shine a light on this: Is perhaps the pressure equaliser broken ?

 

[dave_peters]

I don't think its a problem with the equaliser, more likely when you assembled the slave cylinders there is a collar that is supposed to be the self adjuster around the slave cylinder ram, when you assemble the drums these collars need to keep the ram as far out as possible before sliding on the drum, otherwise too much brake fluid is needed to put the brakes on and this will give you these symptoms.

 

[davew]

Dave P. The only Zetor brakes i have had apart are on the 5511 and 3545. There was nothing like you describe when i removed the drums and nothing is shown in the manuals i have. Would you have some photos or a diagram that shows what i need. Thanks.

 

[hve]

Sounds like the equaliser to me, my 6745 has the same problem but have not even looked at it yet as i still have the front end off.

half travel on both peddles will displace the same volume of fluid as full travel on one peddle, so if the equaliser is stuck or the seals are leaking (internally) pushing 1 peddle results in almost full travel and both brakes coming on (or trying to)

Even half travel sounds a little excessive...... I assume the shoes have some kind of self adjuster, but do not know what it looks like yet (picture in the manual is useless)
but, yes if the self adjuster is not working and the shoe return spring can push the slave cylinder piston all the way back this will upset the system too.

other thing is to use it for a while (with peddles locked together) and let the new shoes bed in, it may get much better by it's self.

do let us know if you find the problem

 

[hve]

Do your brakes look anything like this? https://www.dropbox.com/sh/rok652hrfcc1t4l/X1RL4FLwle#/

Photos from a 6711 post a few weeks ago

 

[davew]

The set up on both my tractors is the same as this and no signs of any adjusters for the shoes. I noticed that the pistons are quite tight in the new cylinder and am now wondering if this is intentional and makes them self adjusting. When the brake pedal is released i can hear the shoes rubbing on the drum which would tend to confirm this. I'll order up some new seals for the equaliser and let you know what i find.

 

[askinner]

Bruntie, I overhauled the brakes in a 6045 a few weeks ago, and the new slave cylinders were the same, extremely tight. I think you are spot on with they need to be so they are self adjusting, as there are no mechanical adjusters in the UR1 brakes.
Having said that, I have not pulled the pressure equalizer apart, this may have a set up that retains a small residual pressure against the slave cylinders (Cat dump trucks have this, it is like a check valve and relief valve in one).
On the pedal travel, they are all the same when using one brake, as the piston in the pressure equalizer has to move completely to one side, and this space obviously needs to be filled by fluid.
When bleeding, mash down hard on the pedals, the routing of the brake lines tends to hold air if you only press down slowly on the pedal.

 

[davew]

Thanks - I got the same advice on bleeding the brakes from an Ex Zetor mechanic yesterday so will give this a go at the weekend before taking things apart. We did take it slowly last time.