M101A2 Brake Flulid

[RJM27]

What Fluid should I use in the M101A2 Surge Brake? Hearing something about Silicone. Were should I buy the proper brake fluid as well. Brakes are working, would like to service the resivoir.
Thanks Bob.

 

[800summit]

Well if it is for silicone, be prepaired for sticker shock. Napa wants $32 a qt

 

[800summit]

DOT 5 silicone

 

[armytruck63]

I bought a gallon of DOT 5 at Napa a few years ago. It was $92 per gallon.

Ask for a fleet/ owner-operator discount (your Army truck counts) or a AAA discount and use whichever saves you more.

 

[doghead]

Surplus stores, about $30/gal. I get mine from Spruce Mountain Surplus. If you only need a little bit, some auto parts stores like Advance Auto have an 8 ounce bottle for about $10. Use DOT5

 

[RJM27]

Sounds like it's DOT 5 (does that mean silicone) would be the spec brake fluid? I'm wondering if I should just use the trailer seeing the brakes are working, or if I should just go ahead and drain and clean and replace? Any Thoughts or experince!!!!!!!
Bob.

 

[frodobaggins]

Guys, can you flush and fill this with Dot 3 like deuces ?

 

[RJM27]

The TM shows a sticker (which is missing from my trailer) that says Silicone Brake Fluid. But I like Frodobaggins idea about drain, flush, fill with dot 3. Does it work??? God I feel like a rookie!!!!!!!!!!!! Can you tell I'm not use to working on Military!!!!!!!!!!

 

[Recovry4x4]

You can flush and fill with DOT 3 if you want. It's made for DOT5 and its worked this far but you can swap it. Make sure you do a thorough flush with DOT3. I'd expect it would take a pint or better to get it sufficiently flushed. If you don't have a power bleeder, thats a lot of cranking on that breakaway lever.

 

[doghead]

It should be fine, if you do a complete flush and change of the fluid(to dot 3). I would just use the dot 5.

 

[RJM27]

Hey guys, I really appreciate the solid advice with the experince. I've been bitten by the GL bug, already been outbid twice a M101 trailers and stuff, now I just gotta get my wife to understand why I need this stuff.
Thanks Again
Bob.

 

[800summit]

the nice thing about using the DOT 5 is the low water absorption.

 

[frodobaggins]

It should be fine, if you do a complete flush and change of the fluid(to dot 3). I would just use the dot 5.

I would too if my motor pool wasn't expanding and I didn't have a couple gallons of Dot 3 around

Good to know it will work in my trailers too.

 

[MarkM]

Found this old thread. You should never switch out types of brake fluid. DOT 3 & 4 are mineral based fluids and DOT 5 is a silicone based fluid. If you switch out the DOT five to DOT 3 the seals in the system will swell due to their incompatibility and vise versa. The seals will prematurely fail over time. I would never take the chance on this swap. Below is a link I made years ago.

PS: I carry an FAA Airframe & Powerplant License in my wallet

http://tccoa.com/articles/brakes/brake-fluid/index.shtml

 

[Recovry4x4]

Might want to tell that to the chemists that work for the DOD. http://www.jatonkam35s.com/DeuceTechnicalManuals/TB43-0002-87replacement procedure brake fluid.pdf

 

[Scar59]

MarkM is spot on. Don't switch the fluids out, big headaches later with bad seals. DOT 5 does not like to blend with any other brake fluid, it will clot up when it contacts any residual DOT 3/4 fluid. I also have a FAA A&P.

 

[patracy]

So why would the military allow conversions?

 

[MarkM]

If you notice the link "Recovry4x4" refers to is switching out DOT 5 to DOT 3 and maybe seals designed for DOT 3 can handle DOT 5 better than DOT 5 seals can handle DOT 3. The answer to that one that I honestly don't know but once done now you have to worry about how well a flushing job you did as any other fluid residue can cause problems. All I can say is I would never do this switch and everything I have learned over the years tells me it's a bad idea.

 

[Recovry4x4]

There are quite a few folks here that did the covnersion from DOT5 to DOT 3 without negative results. One of them is cranetruck. He did his conversion a great number of years ago and never did have any issues with the conversion.

 

[MarkM]

I am not stating it won't work I am just making the recommendation that it may not be the best way to go.