Brakes, or lack of......

[FMJ]

Hey guys, I need some help. One of the M35's I drove back from Santa Fe on monday has bad brakes. I went through the unit maintenance pub, and bled the brakes using the manual method, but I still have the same condition, first pump, the pedal goes down even with the accelerator, second, third its at the top with no bleed down.....the only thing I can see that doesn't look right is the fluid in the Master cylinder looks milky, but I've put a whole, 32oz, bottle of fluid through the system.

I'm kinda stumped, anyone have any thoughts, advice?

Ed

 

[clinto]

First I'd ask if the brakes are adjusted properly?

The manual says that you only adjust the top for maintenance. The bottom is only adjusted when new shoes are installed. Clearance is .020" at the bottom and .010" at the top (I think).

 

[CCATLETT1984]

sounds like your getting air into the system, prolly an issue within the airpak.

 

[sweetk30]

i know most mill trucks use silicone based fluid.

are you by chance using std automotive dot 3 or dot 4?

dot 5 is silicone based.

this is all i can think of off the top of my head. and i have never touched a 2.5 ton system. but i do know thay run diffrent fluid. and are by no way compatible. it will mess up stuff if mixed.

 

[FMJ]

Re: RE: Brakes, or lack of......

sounds like your getting air into the system, prolly an issue within the airpak.

That seems likely, this truck sounds different from all the others when you depress the brake pedal and let off, not the normal airbrake sound, can't really describe it though, is it possible for the AIR over hydraulic to bleed into the hydraulic side? I'm using Valvoline dot 4/5 synthetic fluid.

 

[emmado22]

Whats DOT 4/5 fluid? I'vew never heard of it.......

DOT 5 is the ONLY way to go with the Deuce............

 

[sweetk30]

all dot 4 i have seen is still std fluid just higer range of oporation. you need full syn dot 5 stuff.

3-4 o.k. but 5 only.

 

[FMJ]

Whats DOT 4/5 fluid? I'vew never heard of it.......

DOT 5 is the ONLY way to go with the Deuce............

Ok, so what did they use back in the 70's?

 

[sweetk30]

hell that dont mean much to me. valvoline uses the hell out of syn power these days.

if it dont say dot 5 dont use it.

you will want to get that stuff out asap as mixing them will cause hell on seals and pistion seals.

 

[emmado22]

Back them, they used DOT 3, but changed over Army wide when DOT 5 came out....

 

[ASTFU]

my deuce was doing the same thing i adjusted them and its fine now,.Thom

 

[sweetk30]

quick search found this. http://www.valvoline.com/products/Valvoline Synpower High Performance Brake Fluid.pdf

and i priced dot 5 one time wow is it high priced.

 

[FMJ]

my deuce was doing the same thing i adjusted them and its fine now,.Thom

I'm thinking this may be my problem, thanks!

 

[area52]

Just to squash the "don't mix DOT 3 with 5 " rumor -

there is no problem mixing the two - one absorbs water(DOT 3) and one doesn't. Your seals will be fine with either or both mixed together. There is a post on here some where by D.Doyle I believe in which he had referenced a report by the military stating this information.

 

[FMJ]

Just to squash the "don't mix DOT 3 with 5 " rumor -

there is no problem mixing the two - one absorbs water(DOT 3) and one doesn't. Your seals will be fine with either or both mixed together. There is a post on here some where by D.Doyle I believe in which he had referenced a report by the military stating this information.

Thanks Wade, I was just gonna let it go...being as how it sez on the label compatible with all.....

And again, sorry about the towbar thing in Hesperia, my whole trip went to heck getting that 1009....

Ed

 

[area52]

No problem, I understand when Murphy catches a ride with ya!

 

[CCATLETT1984]

FYI, I had a wonderfull GOO form in my MC on the m1008 when some dot3 got mixed in, two 2qts of dot5 to flush it all out. I'd advise flushing with alcohol just ot be on the safe side. and you can get gallons of dot5 rather cheap from one of the members on here. like $30 a gallon.

 

[chuck500cc]

Dot 3/4 or water buildup/contamination in the system? Just trying to give all sides.

Chuck XD Fan

 

[FMJ]

FYI, I had a wonderfull GOO form in my MC on the m1008 when some dot3 got mixed in, two 2qts of dot5 to flush it all out. I'd advise flushing with alcohol just ot be on the safe side. and you can get gallons of dot5 rather cheap from one of the members on here. like $30 a gallon.

Well, the only thing I've added to the system since I picked up the truck was the stuff I showed in the pic, I think my problem is adjustment related, I pulled a hub last night because I thought I had a bad wheel cylinder, but it turned out to be a bad inner axle seal.

 

[Blood_of_Tyrants]

I second the brake shoe adjustment. They are probably automatic adjusting brakes. Drive in reverse and then apply the brakes. Do this several times to adjust the brakes.