deuce master cylinder

[wcolt45]

New guy here,deuce is 3wks old to me ,sorting out the bugs and narrowing down the spongy feeling brake pedal,stops well but feels soft,had to add fluid when i got it,but the question i have is when the pedal is pushed firmly and let up the pedal returns rapidly ,but noticed the piston in the master cyl is slower to return,is this normal? Or is my mc shot? Thank you

 

[R Racing]

I just replaced mine because mine was leaking past the O rings but it returns as fast as I lift my foot. what brake fluid are you using? If its DOT 3 you should change it out to DOT 5.

 

[wcolt45]

I refilled with dot 5,and thats what was already in it.Would simply bleeding the system have anything to do with this? Hate to bleed then end up having to replace the mc

 

[bones1]

Sounds like there may be some air in the system. Get a buddy and bleed it a few times and go from there

 

[FireFighterHill]

do a forum search for power bleeder and remote reservoir. One is a tool thats easily made to make bleeding brakes a breeze and the other is a mod that will make checking and adding brake fluid easy.

 

[bones1]

http://www.steelsoldiers.com/deuce/29854-brake-bleeding-lesson-hard-way.html

 

[glcaines]

I agree - you have air in the lines. Follow the TM on bleeding as the order you bleed is important When you bleed the brakes be very careful to not let the MC run dry as it doesn't hold much. I would recommend putting together a power bleeder as it will make the job MUCH easier. As mentioned above, make sure you use DOT 5 and nothing else. DOT 5A is also different and cannot be used. You can buy it in bulk from some MV parts dealers by the gallon a lot cheaper than from a parts store. The brakes are the most important part of a Deuce and the deuce doesn't have a split MC system. If your MC fails, you have zero brakes. Good luck and enjoy your deuce.

 

[wcolt45]

Thank you all for the fast response! I have already made up a power bleeder,and waiting on pegesis racing to get the remote reservoir caps back in stock to order,still shopping for a good deal on fluid.ANY SUGGESTIONS?

 

[poppop]

Sounds like you do have some air. But the petal returns by a spring that will pull it right back. The piston returns from fluid pressure from the return springs on the shoes at each wheel. There is a small return port in the master cylinder that prevents the fluid from rushing back and spilling from the vent. Sometimes that return plugs and the brakes will remain in the applied position. If that hole is partuially plugged it could slow the return down and cause your problem.

 

[rlwm211]

I would think that if the master does not improve in terms of its return action that your master may be deteriorated due to corrosion or 'gunk' accumulation.

I would take a peek inside the boot of the master and look for brake fluid seepage. If there is any, it is time to rebuild or replace the master.

You have to keep in mind that the deuce is a single circuit brake system which places a premium on making sure the components are in top condition. Any failure will result in a loss of brakes and a potentially dangerous situation. I would not ever recommend cutting corners when working on the brakes of a deuce.

Best of luck in bleeding the system, and take note if any debris, or water comes out along with the brake fluid.

RL

 

[wcolt45]

Thanks,i'll clean up the area well and look for any seepage.The hole that was brought up,where is it and is it serviceable??

 

[doghead]

It is a very easy task, to remove and replace the MC. If the truck is new to you or having issues, i suggest you remove it, inspect, rebuild and reinstall it, then bleed the system.

I would also suggest you rebuild your air pack now, also. (especially if the truck is new to you)

If you have no idea of the condition of the internals of these parts, rebuilding them will give you years of confidence and good service. Otherwise, your just guessing that they are in good working order.

Once those 2 items are rebuilt, I would do a full wheel bearing and brake service, and inspect your wheel cylinders, while in there.

Even after all that, I check my BFS at least monthly, or more often depending on usage. I check BFS Every single trip when I tow.


The "hole" poppop was mentioning, can be seen while looking into the MC reservoir, at the very bottom. Press down on the brake, then release slowly and you should see the fluid moving up out of the hole.

 

[jatonka]

I have rebuilt and new master cylinders available at all times, PM me if you need one. JT

 

[bones1]

That's good to know, wheel cylinders and kits I suppose as well.

 

[wcolt45]

deuce master cylinder pt2

After the advice of fellow members on ss,i removed the master cylinder to inspect condition for rebuild/replace.What i found was upon disassembly it was full of grease like "stuff" in the bore ,spring covered in it,bore pitted,just nasty,cant believe they worked at all!!appears someone before me refilled reservoir with dot 3,as it looks yellow in color,and doesnt mix with dot 5 in a cup ,i know a new mc is in order,should i rebuild airpak??weather here prevents me from checking at wheel cylinders to see if 3 or 5 fluid is throughout the system. hows the best way to flush to get all the crud out??? Thankyou

 

[hndrsonj]

It is probably a safe bet the the airpack has issues too if the master cylinder is that bad.

 

[wcolt45]

yea,thinkin a rebuild,what about flushing the lines?

 

[rlwm211]

From the sound of it, your master is probably too far gone to be worthy of a rebuild attempt. By the time the bore is honed out enough to get down to good metal it will be so oversized that the rear seal on the piston will weep fluid and be a source of a mess and eventually fail. New Master Cylinders are not that expensive so just replace it.

I have rebuilt airpacks after finding the sludge of all types in the master and to be honest it is the best thing to do. Get a rebuild kit and follow the TM proceedure carefully, or have your Airpack rebuilt.

As to flushing the system, I would use DOT5. Get a gallon of DOT5 from one of the vendors on the site, or who serve the MV community. You will use about half rebuilding your Airpack, flushing and bleeding the system.

When I got my deuce, it had no brakes, a dry system and when I initially bled it, the brakes were marginal at best. I tried rebuilding the master and found much the same as you have. Ultimately I replaced the master, rebuilt the air pack, replaced all the wheel cylinders and packed the bearings at the same time, and also adjusted the brake shoes. After final bleeding my truck has great brakes. It took a lot of work, but I have the security of knowing everything is in proper condition.

You can download the TMs from www.Jatonkam35s.com in the M35 TM download page and I would suggest saving copies of all of them as they are the "Bible" of the care and feeding of your deuce.

Hope this is helpful
RL

 

[wcolt45]

Thanks so much for all the input,you wouldnt happen to know which tm deals with airpak rebuild ??

 

[emr]

a weeping wheel cylinder will do this also, AND the brakes being out of adjustment can also cause this, many many times they are NOT correctly adjusted, there are posts on this, but the easiest thing to do first is look for any signs of brake fluid on the back of the wheels, and then adjust the brakes, a MAJOR brake adjust ment is needed then 3000 miles a minor then 3000 niles a major again, a major is adjusting both top and bottom a minor is just the top there are holes in the back of the drum for the feeler guage, i think, i forget sometimes so look it up... the bottom is 20,000 th and the top is 10,000 th it takes a few times to get em in the right place, just an fyi, this is every bit as important before u go replacing parts in my mind, then bleed the system only after pulling the wheels and making sure a cylinder is not weeping, they can be sneaky, good luck all advise given in these posts are important for your truck, good luck