Master Cylinder goes dry

[Sgt. Sam]

I have a M62 5ton wrecker and the master cylinder goes dry. Takes 3 or 4 month to go dry and I can find no visible leaking anyplace in the system. can someone give me some help.

Sgt.Sam

 

[zxmedic]

It could potentially be going into the airpack , or out one of your wheel cylinders you need to pull the drums and locate it before you have a complete brake failure. My two pennies worth

 

[gimpyrobb]

Yeah, theres lots of places it could be. When was the last time you swapped out the soft brake hoses or checked the wheel cyls? Does it have the "square" springs in the wheel cyls or the tapered ones?

 

[M813rc]

I have a mechanic friend, who specializes in MV's, and he swears that Dot 5 brake fluid evaporates through the vents. With the magical disappearing fluid from my M185, which stopped when I put the vented remote reservoir on and bypassed the old vent lines, I'm inclined to think he may have something. Or ants are drinking the stuff....

Cheers

 

[Wildchild467]

I have a mechanic friend, who specializes in MV's, and he swears that Dot 5 brake fluid evaporates through the vents. With the magical disappearing fluid from my M185, which stopped when I put the vented remote reservoir on and bypassed the old vent lines, I'm inclined to think he may have something. Or ants are drinking the stuff....

Cheers

I'm not sure about evaporates but I do agree silicone fluid always seems to need to be "topped off" every couple years or so. My dad has a couple Studebakers and when he restored them he put silicone fluid in them. When they are restored they always seemed to appear slightly damp around the entire master cylinder. It would take a couple years but he would have to add a little. I am not sure what causes it, but my street rod is the same way also. I know brakes are very important and I have never felt like my brakes in any of my vehicles are or have been lacked needed attention, but it just seems to be nature of the beast with silicone fluid. Look at all the deuces people have that complain about brakes not working right and then find out it is low on brake fluid. It only seems like the fluid "leaks" out of cast iron like i was describing when the master cylinders look "damp". That is just my experience though.

3-4 months is not right though. Something is not up to par with your brake system. If you need a couple of wheel cylinders, I have two. Let me know.