Brake fluid Guidence

[thiswontbetooexpensive]

I had some integrity issues when I got down to my brake lines so I ordered the entire set; from the master cylinder to the wheel cylinders. Went ahead and got all stainless from Inline Tube including a new proportioning valve; for $400. This did include the SS braided lines to replace the old rubber hoses.

This vehicle did not and will not have power brakes, I should be pleasently surprised with the stopping power of 4 wheel brakes!!!

When I get to putting it back together with a new/rebuilt master cylinder (haven't gotten the part yet), what is the better option for brake fluid? Dot 3, 4, 5, or ? Does it even matter?

EVERYTHING will be new on the brakes with the exception of the front calipers; they actually worked and didn't leak. New rear drum wheel cylinders and all. I am just trying to get my all my ducks in a row.

 

[hole]

I'm no expert, but what I do know is from having had an old military vehicle. The military use's dot 5 (silicon based) which repels water. Dot 3 is capable of absorbing water, thats why they use dot 5. The downside to dot 5 is that any moisture that does get into the system will make its way to the lowest point ,IE wheel cylinders. The water lays there, trapped at the end of the line and starts rusting out the cylinders. Wheel cylinder failure is bad in any vehicle unless it happens in your driveway, but when at speed in a 13k lb Deuce and a Half when one let loose on me, I found a few new creative driving skills to avoid killing my fellow man. After tearing everything down and looking at the rust pitted wheel cylinder that failed, I quickly ordered 6 of them to do the whole truck. I also flushed out all that dot 5 and used dot 3 in its place. Not to mention, dot 5 costs about $100 per gallon , so running dot 3 and flushing the system out every 4-5 years to make sure I was getting all the moisture out was the way I chose to go.

 

[thiswontbetooexpensive]

As I have access to corrosion inhibitor, I was thinking of adding some to whatever I go with. It doesn't take much, like maybe 2-5mls/qt of fluid. This CJ won't get used much, I will talk to some of our corrosion PhD's here and report back when I get a response.

I appreciate the input Hole. Have a good one!


This won't be too expensive Dear! That's what I keep saying. Over and over again.

 

[steve1973]

DOT 3 or DOT 4. Dot 4 is reverse compatable with 3. As mentioned, DOT 5 is very expensive and used in Military and racing applications.

 

[73CJ]

Been using DOT5 for years. I submerge them a lot. I use it in the hydraulic clutch as well. No problems

With DOT3 I would get pits in master and wheel cylinder bores. Kinda the opposite of holes experience.