hi everyone new to volvos. i picked up a v70 wagon 2.4 for 600.00.
love the car, runs perfect for 238.000 miles, but it seems the master cylinder is going out(not a big deal). pedal slowly goes to floor when held, in park. looked for signs of fluid by hubs, none.
so i bought a used MC on ebay of all places(i know new would be better)
but I'm disabled and pretty poor.(not complaining so used one for 30.00.
i researched thought i had the right part( i thought i had dstc but turns out
i only have stc. i bought oem R234420 and whats in my car is 8646007
that former is for dstc latter 8646007 is stc.
so i may have to exchange with the guy. i just bought last night so it hasn't been shipped.

the thing is they look the same, EVERYTHING. so is it internal or what?
just in case i get the R234420 wondering if it will work. all hookups the same. bolts on the same. i trust other car enthusiasts over anyone.
sorry this is so long but will it work?

the other thing, as the master has been going out i put in some dot3 instead of dot4. ok for now? I'm going to have the fluid completely
drained and replaced if necessary.
thanks for input, Don


ect...

 

only used about half bottle dot 3 bought dot 4 and was able to put so in after driving a week. i know now that they are similar. different boiling points.
another question, does brake fluid have any "movement" in the lines? will the dot 3 and dot 4 mix? as the car is used?
not does it mix out of the bottle, but i mean as i said is there movement.

 

difference is the way it hooks up to the booster. if anyone cares.