Zetor 5340 Brake problem

[djsumcp20oldleawharfcouk]

The foot brake pedals when joined are very hard to press and not working. Separating them the left hand works but right does not, goes down a little bit. If pushing down both by hand a little then putting more pressure on one the othe rises.
Is this a Master cylinder problem?
How do you access the Master cylinders? I cannot see them are they behind the Dash panels?

 

[djsumcp20oldleawharfcouk]

Have taken covers of off rear brake cylinders, the left hand one moves slightly when pedal pressed, the right hand one
which the piston is already parltly moved down does not move when pedal is pressed, and is not returning. How can I prove whether the master
cylinder is not retorning or the brake disc's are ceased? If I open bleed nipple will this prove it?

Still cannot find any information on how to access the Master cylinders, the workshop manual does not say anything,
they are behind the red panel in the cab, the black part at the bottom has no access bolts on the other side the black panel has
an access panel to get to the clutch master cylinder. I cannot imanage you have to dismantle all instrument dash panel and
remove the red panel around it. Does anyone know how to get to them.



Thanks David

 

[ixer0]

Undo the pipe on the slave cyl and see if fluid comes out when you pump it. M Cyls are accessed from the outside through panel in front of cab. Mike

 

[djsumcp20oldleawharfcouk]

Thanks for the reply, I will try opening bleed nipple, I have slacked off the adjuster but the piston is still in the same postion. I will take off panel at front to see if I can access the master cylinders, there is another panel in front off that which holds the sides of the bonnet together.
On the adjuster there was about 15mm thread showing, the manual states if more than 10 mm the disc need replacing.

 

[djsumcp20oldleawharfcouk]

Yes I was able to see the Master Cylinders after removing panel. Quite difficult removing because it has a lip at the bottom which is under the bottom of the Dash panel, but using a small piece of wood to force it away managed to remove. I suppose there is just room to undo pipe connections.
Anyway I think the master clinder is ok, opening bleed nipple and pressing pedal fluid comes out ok, closing bleed nipple and pedal is hard, piston or rod not moving. Took bolts out of slave cylinder and the rod going into the cylinder will not go in any futher and if pulled back is just loose, I think the pistion is stuck up. Cannot understand how it works with the hand brake, if that pulls the rod down, I assume the hole in piston is long enough. I think the rod has come out and wedged on the bottom of piston.
Have ordered new slave cylinder but do not whether the brake will work because it was adjusted right up.

Thanks for advice David

 

[ixer0]

I shouldnt worry too much about the measurement on the adjuster. Jack it up and tighten the adjuster until the wheel locks. Then back it off one and three quarter turns.

 

[djsumcp20oldleawharfcouk]

ok thanks I will try that.

 

[djsumcp20oldleawharfcouk]

Have replaced right hand slave cylinder, was all siezed, rusted up.



Having problem bleeding, the pedal becomes firm and then syddenly goes right down,
think master cylinder is problem.

There are two shown.


marked as old one.


How to identify the correct one,
at the pedals it has a 3 fluted rubber which from picture on web is
the old one, but behind pedals the outlet is about central of the cylinder
like the one with the single rubber, on the old one it is nearer the front,
with a longer part of the cylinder at the back.

 

[ixer0]

You need the shorter type. Part No. is 6245 2712. Could have either rubber boot, doesn't matter.

 

[djsumcp20oldleawharfcouk]

Thanks