Any ideas had to change master cylinder on front brakes and now brakes work but when brake pedal is held for a while brakes let go and machine rolls and has no air leaks
You have an brake fluid leak somewhere. What kind of fluid did you put in the system when you changed the master cylinder?
The dealer said use dot4 and have not lost any fluid out of res in 3 days the thing is the brakes dont always stop holding its intermiten some times they work great
Tec, if memory serves me correct, there is a reset pin on those master cylinders.. if it gets over stroked you have to manually reset it by pushing it in and then it should stay in. If the brakes are not up to adjustment or the hydr. system is low or has air, it will overstroke again causing the pin to step out.
grandpa, I believe this pin you are referring to the one that operates the "over-stroke" light in the cab. It will pop out and turn the light on but has no real effect on the operation of the brakes themselves. If this machine is loosing braking power I might be able to see where if the master cylinder is over stroking the rubber cup may be getting damaged or just reaching a point in the cylinder that is allowing the fluid to leak off. One thing I don't understand is the mention of the machine starting to roll away. If this machine has separate front and rear brakes and the problem was only with one master cylinder the other axle should hold it from rolling. Yes, braking power would be reduced but should not let it roll. Unless the intermittent problem is only when stopped with say a load in bucket and on a steep ramp or hill. I'm thinking I would have someone push down on the brakes and hold them there while I watched the fluid reservoir to see if there was any sign of fluid coming back while brake was held on. Seems if there is no external leaks of fluid it almost has to be internal leaking back to the reservoir. Would also not be a waste of time to tee in a gauge on the air line of the master cylinder to confirm that air pressure is not dropping with brakes held on for a period of time. I'll think more on this and if the old memory banks come up with more ideas I post them! While I'm thinking, what is the S/N of this machine? Guessing this is a disk brake set up? Dry disks or disks in side the finals?
Mine is drum break, when they work they kind of work lol, the manual says put it in revers and hit the throttle for a reason. On mine the drums are worn so the shoes wear quickly and the break cylinders over stroke and leak.
That's why it is so important to include information like S/N. There are many variations of what looks like the same yellow piece of iron!