Case 580 Super M service brakes soft

[troyharnish]

Hi All;

I have a 2006 Case 580 Super M, series 2 with about 2500 hours on it, everything has been pretty much great with it, except for a recent hiccup with the service brakes. They have worked well all along, and with the colder weather and a bit more roading, they are acting up.

When I first start the machine, the left brake has to be pumped up a bit, and both pedals slowly go to the floor as the system loses pressure. If I take my foot off and then back on, they work but still slowly go soft. Can't see any leaks, always have brakes but the question is how often I have to pump them. One day they were almost normal, but now several days of the brakes going soft.

Any thoughts or insight?

 

[Goose]

Sounds like you are leaking internally in the master cylinders. If the pedals leak down while applying both brakes locked together you either have one or both master cylinders bypassing or the brake pistons are leaking in the rear axle. If the pistons are leaking you will be adding oil into the rear axle. You can unhook the 2 brake lines at the rear axle and plug and see if the brake pedals still go down. If they do the problem is in the masters.

 

[troyharnish]

Thanks for that. Any idea where I would find where the brake lines come into the rear axle?

 

[casetech7]

pull your FILL plug on the rear axle and expect to have oil come out let it drain to the proper FILL level put the drain plug in and heat the oil up in the rear by driving the machine park it and let it sit for about and hour pull the FILL plug back out…you'll probably pull .5gal out…that means your brake pistons are leaking…9 out of 10 times thats whats wrong

 

[troyharnish]

Thanks for that. I'll give that a whirl tomorrow.

Just to add to how the brakes behave, I just noticed that if I press and hold the right brake, it does not bleed down and it has plenty of holding power. If I press just the left, it goes right to the floor with no brake engagement, and using just the left pedal, it does not build any pressure when you pump it. If you press both pedals together, both pedals will bleed down and I get some grabbing power in the left pedal, which will bleed down if I hold just the left or both together. Whatever is happening, it seems to be the left side that is causing problems. Afterwards, holding just the right will give me the same results (lots of brake hold, no bleed down).

Is it a big job to have the brake pistons repaired?

 

[casetech7]

theres really only two major brake components in that machine first i would check the rear level and thats probably the most simply check, i would also do what goose said just to be 100% but your about due for brakes…think about it like the brakes on your car once you've driven so long with the squealers on the brake pads yelling at you telling you they need to be change stop squealing and the brake pad falls out and piston in the caliper usually cracks and falls out and your left with no brakes…the reason your brake pedals slowly drift to the floor while there pinned together is because the master cylinders are joined by a small hose and your opening the spool in the master cylinder on the left side….unfortunately its a pretty big job the rear needs to be pulled from the machine

 

[troyharnish]

Ah, that completely makes sense. The brakes were a little loud prior to this, makes sense the piston would come to the end of its travel and give me these symptoms. I appreciate the insight, having an idea of what I am up against helps with the planning.

 

[casetech7]

not a problem glad I could help you, also keep in mind using good the right oil-hytrans oil in the hydraulic tank, transmission and in your models rear axle with the axle brake additive goes a long way for performance and durability, some customers who do there own services come in with a groan in there brakes and ill put the additive in and it clears it up good...

 

[troyharnish]

I always use Case fluid for everything, I am a big believer in quality lubricants, although I did not know about the additive. I'll include that.

 

[troyharnish]

Just to follow up on this thread, I had the backhoe into the dealership (finally), and the master cylinder on the left side was shot, as well as the brake lines (heavy corrosion and some holes). Replaced the master cylinder and brake lines on both sides, everything is great now.