Giving up on M135.........

[CAPSARME]

on a side note, dont shoot that AP ammo in your M1... its loaded to full pressure allowed for a 30.06.... M1's actually have a special, lighter load for them. If you shoot the AP you WILL bend the operating rod.... even commercial 30.06 hunting ammo is too hot for it.

Just a heads up, not trying to be a know it all...

 

[Brad]

OK Friends, I('m giving it another try. Picking the hotest day of the year, why not.
Anyway cant figure out why this thing keeps locking up ahen brakes are applied, and then taking 10 15 seconds or more to slowly release.
So my son and I blocked this up so all the wheels are off the ground.
Start engine, build up air and hit the brakes. One front wheel locked up tite and would not release at all. After a minute or so, still tite. Just happened to hit brakes again and it immediatly released.??
After doing so and checking all wheels they all seem to be releasing correctly now. Even the bad front wheel.
So, bad rubber line?? On just that wheel??
I need to go over it some more to be sure its just that wheel. I am sure that when driving the truck it seems like all the wheels are dragging???
Is there anything I could do to test this while I still have all the wheels off the ground???
Thanks

 

[steelypip]

Easy test: Open the bleed screw on the wheel cylinder while it's stuck locked up and the others are released. If fluid spurts out and then the brake releases, you've found the culprit - it's the wheel cylinder hose acting as a one-way valve.

If fluid does not spurt out, then you've got a problem with the brakes on that wheel.

 

[135gmc]

I'm running on pure memory on this one - but as I recall, the master cylinder for the GMC and for the M35 REO is ALMOST the same - the only differencee is that one truck has a spring-loaded pressure retaining valve in the cylinder, and one does not. I THINK it is the GMC that does not have this valve. If you install a REO master cylinder in a GMC, and you don't remove the valve, the brakes won't fully release.

Again, this is by a very faded memory - but if you replaced the master cylinder, it might be something to take a look at.

 

[Brad]

This is going to be my last go around one way or the other.
I have all six wheels off the ground so that I can try them all, or anyone of them at any time.
What it seems to be happening:
When I depress and then release the brakes the front drivers side wheel locks up so tight that I cannot turn it. All other wheels seem to be dragging, but I can turn them with medium effort.
When I cracked a rear wheel bleeder the all seem to release immediatly??
From what you guys have pretty much all told me the same thing, sounds like that front left wheel hose is bad, as well as the air pac??
If it is the airpac, just what do I do??? What do I look for?? How do I fix it?
Thanks as always. Does anyone know of anybody in western Pennsylvania that knows about this stuff???
Thanks

 

[marchplumber]

Feel your frustration. Yet, anything worth having is worth working for. One day at a time, I'm always told. Maybe a professional heavy wheeled mech from a local shop could be persuaded to be of some assistance.
God bless,
Tony

 

[m1010plowboy]

What did you find when you went through the trouble shooting section of the TM's?

I see ten steps to solutions for you symptoms before you call a mechanic., Air in system is one and the solution is to bleed as per TM.

Have you serviced your air-pak? gigity

If it was mine I'd just take it all apart and put it back together, then send it to a brake shop to get it done properly.

 

[Brad]

Thanks all for the advice.
I have been working on these brakes, off and on, for three summers.
Finally last summer we sent the airpac out and paid over $300 to have it rebuilt. Since then I have had these "locking up" and "dragging" problems.
I have rebuilt or replaced all 12 brake wheel cylinders. Have bled and adjusted them many times. Have tried to determine if it is any of the rubber lines.
For awhile I had the brakes adjusted completley back, as loose as possible. That was I was able to get around with it in a couple local parades. But it was still dragging, and a couple times locked tite. This is too hard on the truck. Besides, I want it right.
This is my Fathers project and we spent many many happy hours, and many hours arguing over things, as we toiled away on it.
Now he is in tough shape and its the only thing he really seems interested in, so I cant just get rid of it. For me, it is just tooo hard and tooo heavy for my taste, though it sure is a neat old truck when it's working.
If we never do anything else with it just the time I have spent with my Dad as we worked on it was great,
But it is not he and I anymore. He cant do a thing, sometimes cant even stay out with me while I work on it. So that part of the fun is gone.
I have suggested to him we sell it while it is still in great condition, but he will not hear of it. He and Mom could use the money to help pay the help we now have to hire to help with him and her. But he just isnt quite right since his (our) stroke.
I will go thry the TM as best I can, but I am not a real mechanic and I do not understand everything. Just wish there was someone around here that could come look at it and at least tell me what to do, though I'd rather just be able to pay someone and "Git Er Done".
Thanks again friends and please forgive my ramblings. Sometimes it can get a little emotional around here!
Brad

 

[Brad]

Finally ready for last try??
Friends, If you have been reading this subject you know what I am dealing with.
I would like your opinions on this...?
I now have the opportunity to give it another shot.
I have the truck all six wheels in the air on blocks. I have all six wheels evenly adjusted.
With air pressure built up, I depress the breal pedal, and when released........
The front driverside wheel remains locked and I cannot budge it. From all your comments and suggestions I must have a bad hose. Because when I crack either bleeder on that wheel it free's it up and it will turn the same as the others.
But, also when the breaks are released the other five wheels are tighter than before pressing. This loosens up within a few minutes.
Perhaps there is an issue with the airpac also???
If I get that front wheel to work the same as the others I think I might just back off all the wheel adjustments and see if that makes a difference.
One last thing. With the cover off the master cylinder, when I push in the pedal I can see the fluid go down. Once released, I see fluid coming back. Doesnt this mean the master cyl is ok???
Thanks everyone for all your help. I sure need it.
Brad

 

[m1010plowboy]

Buy more brake fluid, remove questionable lines, inspect then tell us what the condition of the lines are.

I like pictures.

You did not tell us about the position of the brake switch on the dash yet so lets start there.

 

[USMC 00-08]

Brad..I just read through this thread and although I have not had the opportunity to mess with my M135 at all, I had a similar problem with my 91 Ford F-150. (Very different vehicles I know!) Anyway, after replacing the master cylinder with a brand new one, my brakes started locking up but usually one wheel at a time. With a lot of time, they would release on their own. I don't know much about working on vehicles and after several trips to different mechanics, one guy finally figured out the problem. It was the proportioning valve that had some form of debris blocking it and not allowing the brakes to release as they should. I don't know if these trucks have a proportioning valve as my truck is 370 miles away at the moment, but maybe this is your problem if the M135 has this.

 

[Brad]

Hope this reply works. I have more trouble with this computer than I do the old truck.
I tried to attach a photo, we'll see??
Anyway, That break switch on the dash, we took that thing out of the line a couple years ago when we were having other break problems. So it's not the issue. I guess.
I am going to try and get that line off today. Is there anywathing else it could be at that wheel other than the line.
It locks up tite but when I crack either bleeder it releases. I dont see how it could be anything else at that wheel???
Thanks guys
BTW, I see yer looking for a tail gate? I dont have one of those but I do have a cab with some parts, doors, hood, etc. Also a bunch of bed bows, tarps. But not a new air pac unit!!
Thanks again and again.

 

[Section8]

Hello Brad,
I have been looking at this thread off and on and see you still have a break release problem.
If you have replaced all of the wheel cylinders could it be that by chance you have a canadian built cylinder on that wheel?
The canadian wheel cylinders have longer rods (pins) that hit the shoes.
If this is the case the wheel will lock up and will take a fair amount of time to release from the built up pressure in the cylinder. Once the pressure is fully drained the rods (pins) will have backed off enough for the wheel to turn.
I will do a quick search and see if I can find the relivant info and let you know the different rod (pin) sizes.
Just my two cents on the situation.
Good luck!! Don't give up!

 

[Section8]

Still looking for the info but I do recall that some one had this issue and they rplaced the wheel cylinders and used the canadian made ones by mistake. Their wheel would lock up tight untill the brake sytem fully bled itself back.
The solution was to replace the rods (pins, pistons) with the old one into the new cylinders! Presto!! Problem free braking!!
So if you have the time and kept the old wheel cylinders that you replaced and try swapping the rods ( or whatever the heck you want to call them)and see what happens. May be that simple and not cost you anymore money.
Anyone else recall this topic I am reffering to??

 

[m1010plowboy]

That info on the wheel cylinders is buried in here somewhere ...Section8, Section9, Section3. Gunfreak has it memorized but I'd need to dig.,

http://www.steelsoldiers.com/archive/index.php/f-18.html

and here, http://tinyurl.com/kfuxljv

If it's wheel cylinders it's a good thing it's in the air, safely blocked and waiting for a beating.

Tried to post some photo's of page 464, Brake Pedal and linkage. Shows how the pedal returns to the fully released position. Having the books at hand is awesome.

When you check your lines, replace if you need to (or park truck) then we'll look at the pedal travel.

Here's a blurb off page 464, then I'll leave you to it. It's a holiday weekend up here and I'm bushin' in the 6 bye bye

_________________________________________________________________________________________________________________________________

"""""""""""""TM 9-8024 para 241. b. .......If piston and cup do not return completely to end of cylinder, bypass port between cylinder and reservoir will be closed and fluid returning from the wheel cylinders cannot enter the master cylinder reservoir. Proper brake pedal linkage adjustments must be maintained to insure return of master cylinder piston to end of cylinder. Adjustment is made at master cylinder piston push rod.

__________________________________________________________________________________________________________________________

...Then they give us a bunch of steps to do that...... but step one....brake lines.

 

[Brad]

I have adjusted the linkage. There is play in it and I believe it is returning the entire distance, I mentioned in an earlier entry that , with the lid off the master cyl, when I depress the pedal the fluid goes down and when pedal is released the fluid level comes back up, Would that not suggest that it is working ok??
BUT!!, indeed I replaced all four front wheel cylinders and I bought them from a Canadian company. I believe "Niagra Equipment" or something like that. They came with new rods. He told me the only difference was the diameter of the cly??? I will find his contact info and ask him if there is a differance.
I still have the old rods, but what a job to remove those two front wheels again. Of course if that is the problem I will do it.
But really wondering, why only one wheel is locking up solid??
I guess now I should wait to replace that hose?? It might not be the problem??
Thanks as always.
Brad

 

[USMC 00-08]

I will be in touch with you about the bed bows and possibly some other things when I can finally get to work on the truck. Thanks for the heads up!

 

[Brad]

Hi everyone,
I am still battleing these breaks.
Am trying to find phone number for "Niagra Military" or maybe "Niagra Surplus"??
Not sure of the name. Its where I got the front wheel cylinders from this spring.
I got the name / number from someone on here.
I am embarrassed to so that I cannot find it among my notes, etc.
I need to talk to him and find out the length of the rods that he supplied me with the new larger dia cylinders.
The length was the same of the cyl.
I actually do not understand why longer rods would make a differance in how fast the breaks released?? If they are physically able to relaease at all, why would the rod length make any differance in time??
But alas, I aint tooo bright.
Thanks for all the help guys.

 

[Heath_h49008]

Find someone with a brake pressure gauge and stop replacing parts blindly.

You need the gauge, and half dozen fittings to adapt into the lines.

You have residual hydraulic pressure in the system. It can only come from:

A: Master Cylinder not releasing completely.
B: Airpack not releasing completely.
C: Collapsed lines not releasing.

You know it isn't a single hose collapsed to wheel cylinder, because it is effecting all wheels at the same time.

Track the pressure and you will find the culprit.

 

[Section8]

If my intel is still current. Appologise if it is not. Or wrong vendor that you are looking for.
Niagra Military Parts
86 Dover Welland Ont.
Canada
905-732-9492

Hope this helps.