My shop manual and master cylinder reservoir cap call for DOT 4 brake fluid for my '92 Volvo w/ABS.

But I can't find any straight DOT 4. The only fluid I can find around here is straight DOT 3 or a kind of a fluid that claims it "exceeds DOT 3 and DOT 4 and can be used in place of either." I found both NAPA and Castrol in this DOT 3/4 version.

Is this 3/4 fluid OK to use? Would it be better to wait and order some straight DOT 4 fluid like ATE? (Or is ATE fluid 3/4 too???)


Also, this 3/4 fluid says it "is compatible with conventional fluids". Does this just mean this fluid will work with any other brand of fluid, or does it mean this fluid is some other formulation?

TIA
Dave S.

Buy DOT 4/4+ at Autozone or any mass merchant: Castrol LMA, Valvoline, ATE, etc. As long as it meets DOT 4 standards for boiling points, you are fine. I particularly like the Valvoline Synpower product.

Steve,

I ended up with Castrol LMA. Is that OK for Girling? (I've seen some claim DOT 3
screws up the rubber parts).

Dave S.
Ames IA

That's fine. In old (read: fifties vintage) British cars, there was some degradation in seals. That's not been the case since about 1970. The DOT grades specify ONLY the wet and dry boiling points, not the chemical composition.

Try Jockos in Ames for Castrol LMA and KMart or Walmart for Valvoline.

Thanks Steve--much appreciated.

One other Q--do you advocate clamping the flexible hose when retracting calipers,
or do you figure opening the bleed screw is enough?