Very weak brakes on a 5711

[sveinha]

If the cab was delivered with the tractor from the factory, the model number should be something like 5718? The nameplate states 5711c. Found this nameplate on the cab.

 

[forterra9641]

Thats the nameplate of an original zetor cab. the type is BK 6718.

 

[Renze]

It does look a bit like the 4718 cab, the narrow type. On the 6718 of my brother (and i think also our old 5718, now long gone) had the cab mounted in rubber bushings, not with two bolts on each side, through the cab frame.

 

[sveinha]

The rear wall/window is home-made by previous owner but looks great. I would believe it was original unless told otherwise...

The brake problem was leaking slave cylinder. In the brake house, I dug out almost 1/2 litre of various sludge from brake fluid, oil, leafs and a couple of spruce cones...

Changed the seal to the gearbox as well. The original seal was a zimmerring 58-80-13 which my local shop didn't have in stock so I put in two 58-80-8.

I used about 4 hours to do one side but so far I haven't connected the brake pipe. As long as the nut on the brake pipe is as long as about 5-6 cm it is virtually impossible to loosen them without destroying the pipe. Had to drill out the rest of the pipe from the nut.

Doing the other side during the week and the hydraulics when finished with the slave cylinders.

 

[sveinha]

Brake job finished. It all took about 12-13 hours but now ALL brake parts are brand new

Needed new copper washers on the bolts on the outlet side of the master cylinders as it obviously is not 100% aligned. The old washers were slightly misformed and didn't seal at all. Anyone who knows what the cylindrical unit on the outlet of the master cylinders are?

I may believe it to be some kind of pressure equalizer for balancing the brakes when using both brakes simultaneously?

Both brake pedals springs a good deal as if there is air in the system but I have bled a lot and there are no more air now. Is this normal or should the pedals stop in one more or less fixed position?

 

[alan]

Yes it is a pressure equilizer

 

[dave_peters]

You are right, its a brake balancer, inside is a shuttle valve that stays central when both pedals are pressed, but moves when only one is pressed

 

[grumpy6711]

my brakes are not the best in the world and have only one tractor for experience but if i split the pedals and use either one there is quite a bit of pedal travel, but when pressed together hardly any travel at all.
so i guess thats the equaliser working as it should?

there seems to be something else missing from your tractor Svein - lots of rust and dirt

 

[sveinha]

You're absolutely right, Grumpy, very little rust and dirt. Previous owner did a good job with the renovation of the tractor. He bought it more or less like a wreck 7-8 years ago.

I think I have to use very much power on the brake pedal and think it's a bit strange compared to the hand brake which is exceptionally good. Different technology but they share the same brake drum...

 

[forterra9641]

you say thath you have to use very much power on the pedal..... did you change the brake shoes when you had it apart ? if not and the old liners were soaked in oil and brakefluid, even if you wiped them. the shoes may be slipping inside the drum. when this assy is dry and new you should not have to use much force on the pedal. also a thougt is that the seals where damaged during reassembly. or that the fix with two simmerings is not functioning.

 

[sveinha]

I changed the shoes as well. Cleaned the drums very well.

If I have damaged the simmerring, I don't think the oil would do any harm so far since the tractor almost haven't been moved and the oil level is far below the simmerring.

Both sides seems equally bad...

 

[ixer0]

Hi,

After you've fitted new shoes you need to run it round the yard with the pedals pushed down hard, to bed the shoes in. It may seem a bit brutal but you've got to bed the new shoes in to the old drum !

Mike

 

[Renze]

Hi,

After you've fitted new shoes you need to run it round the yard with the pedals pushed down hard, to bed the shoes in. It may seem a bit brutal but you've got to bed the new shoes in to the old drum !

Mike

Indeed, but dont go faster than 4th gear: in 5th you wont see when they start to smoke. You should take it easier when the first smoke is coming, then they brake perfect, my 3011 brakes harder than a modern wet brake tractor

 

[sveinha]

Thanks.

I drove about 300 meters in third gear and made a lot of smoke today. Works far better already

 

[gav]

that is one old tractor to have brake pedals like that ..yes your right it is a brake equalizer on the end of the master cyln ...if its still spongie try disconnecting the return springs on the pedals and let them rest against the plungers if they have a lot of travel before coming to rest set the plunger pins up to take the slack up but don't over do it or they'll bind on ..the brake pedal's at the top usaully have 2-3 cm of play before the brakes should start to work ..and when set right use both feet and press each pedal and you should be able to push one down and force the other up and vicer verser ..then when you press both the pedal's at the same time they should be firm and not go down as far as when one is pressed ..

 

[Renze]

yes, its a pressure equaliser.