dot4 in when mineral oil needed

[ppea]

I buy a tractor that requires mineral oil in brakes or lhm and the owner before me uses brake fluid(dot3 or dot4).the tractor front brakes are oil bath type and when i run the tractor fast ,the brakes are hot but works perfect.the wheels are free.I think the dot4 ruin the seal.any ideas?

 

[oldnslo]

Dot 3 Brake fluid will ruin seals meant for mineral oil use. If my memory is correct it will cause the seal material to swell and or turn mushy.

 

[ppea]

Only dot 3 wil ruin the seal?

 

[oldnslo]

I should have stated both Dot 3 and 4 will ruin seals meant for mineral oil use. EPDM is seal material required for use with brake fluid while Nitril (buna n) or FKM (viton) is used for mineral oil.

Depending on how your tractor is made the DOT 3,4 brake fluid may not have made it to the wheel cylinder. It could be majority mineral oil still in the brake lines and wheel cylinders.

 

[ppea]

In tractor it was dot3 or dot4 when i buy it.I made same mistake and replace with the same dot4 and then i saw the front brakes are hot when i runing fast on road.I thing it's to late and the seal are damage already.

 

[RayIN]

Regardless; I'd flush the brake system ASAP and install the correct fluid. Might require new wheel cylinders and master cylinder too.

 

[ppea]

the problem is i didn't find the seal for front brakes.I try to put mineral oil and i hope to work.

 

[caver]

My Case backhoe specifically states hydraulic fluid. Not long after I bought it from a dealer both seals on the master cylinders started leaking. I suspect someone just topped it off with brake fluid. I ended up replacing both master cylinders as at the time I couldn't find a rebuild kit.

 

[LouNY]

It could be crud and rubber particles blocking the return from the master cylinders and maintaining just a bit of back pressure in the system,
Cleaning and flushing with the good mineral fluid may solve the problems.

 

[ppea]

I change to mineral oil but the brakes are still warm.The problem is i didn't find the seal.