M 1028A2 master cylinder cap stamped dot 3 brake fluid only?

[sksAL]

so, when it was low, i topped it off with dot 3. from what im reading here now, this is a bad thing. somehow a civilian mc lid end up on this thing?

 

[doghead]

Never seen that.

Did you buy it from an individual or the Gov?

Government vehicle all use dot 5.

If I were you, I would open a bleeder at a wheel cylinder and get a small sample of fluid. Then determine which fluid was in the system. Easy to do with a few drops of water.

Dot 5, it will separate in a few minutes. Dot 3, it will not.

 

[dependable]

Test fluid to see what is in there. DOT 3 will absorb water. It will bead in DOT 5. It does not matter which you have so much as it matters not to mix them.

 

[sksAL]

got it from a board member that got it from a tenn municipal sale, as far as i know. it was on my local craigslist. great truck, dont wanna monkey up the seals with wrong fluid forsure. ill get a sample from a bleeder as soon as this crazy kentucky weather warms up. (moved down to get away from this shyt) thanks for the response guys, ill post results when i get'em.

 

[1956_4x4]

You really need to check to see what type of fluid is in the system prior to adding new fluid. I've been at bases where the CUCVs were changed over to DOT 3, but they were always marked as such.

Smitty

 

[doghead]

A logical guess is that someone bought a replacement master cyl from a public retailer.

 

[sksAL]

im thinking the tenn muni barn mechanics may have replaced the mc and bled the whole system, changed over to dot 3. the guys certainly wouldnt put expensive dot5 in if they knew a standard dot3 would work. the brakes on this truck work great. the fluid loss is tiny, if it sits for a long time a leak develops at the rear of the mc. old stuff leaks when not run regular. ill know when i open a nipple and see purple or gold fluid i guess, or do the water separation test.

 

[dependable]

You can always taste it..just kidding. The DOT 5 turns does not stay purple for long, you should test it.