stoverz28

iTrader: (8)

I have a Mcleod adjustable master that I bought used. When I bought it the guy said not to use a synthetic fluid because it will ruin the seals. Does anyone know if this is true?

I suspect that my fluid could be boiling on me so I want to change to a DOT 4 instead of the DOT 3 Im currently runnning but I can't find a DOT 4 non synthetic break fluid anywhere. Does anyone know where I could find some? I've checked Aline, Autozone, Advance and Walmart.

Any help is much appreciated.

haacer

iTrader: (1)

A quick Google search shows that this is a popular question. Do you have the part number for the master cyl? I'd imagine that there is a tech sheet or somesuch showing compatible fluids.

The consensus online is that DOT 3, 4, and 5.1 are polyethylene glycol based and therefore mix. As you're well aware they have different boiling points so there is a definite advantage to be had by changing fluids.

I would try google with the pn from your master cyl and go from there. I can't see why putting DOT 4 in would be a problem.

Billy M

We use a E.P. (Ethylene Propylene) rubber seal in our master cylinders and hydraulic bearing assemblies. The E.P. seal uses a mineral based fluid DOT 3 & 4. A Viton seal is required for use with DOT 5 fluids.

stoverz28

iTrader: (8)

^So what you are saying is that I just can't run silicone based DOT 5 and that a synthetic DOT 4 is fine?

Billy M

Yes Sir that is correct.

stoverz28

iTrader: (8)

Cool I appreciate the help. I geuss thats what the dude meant when he said not to use synthetic fluid.