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

[Brad]

As always, thanks to all.
I will try that number right away. And I will try and find a brake pressure gauge.
Now, please give me yer opinions on this thought. Since I now have rebuilt or replaced all the wheel cylinders and they should all be working well, what if I would by-pass the airpac unit. I had tried this befor a couple years back and it did not work. But that was when ALL the wheel cylinders were all corroded and very hard too move.
If I would just by pass the airpac and were able to get the brakes to expand that way it might work well enough. I am not hauling anything heavy, only the truck's own weight??
Also then, if they continued to drag after pushing the pedal I would know that it is not the airpac?
Just a thought. I have no help here and it is hard to do anything requiring allot of physical activity.
Thats why I am seriously thinking that I am going to have to give up on Dads truck. I hate to, but I just do not have the answers, or ability to keep on blindly trying things. Nor the money to do so.
I'd do anything to correct the problem if I just knew what to do.
But as always, I certainly apprecoate all the help you all have offered.
Brad Foust

 

[Ferroequinologist]

Try bypassing it. If they work and go back in correctly, then your airpack is at fault. I wouldn't drive very far or fast without the airpack though, as it takes quite a bit of foot pressure to stop one even unloaded.

 

[M215]

If I have read your posts correctly, you have not replaced the rubber hoses yet? If all but one wheel cylinder releases when you let go of the brake petal it has to be a bad brake line. Most likely the rubber line to the front wheel or possibly a corroded steel line. You have confirmed this when you stated that the wheel cylinder releases after you open up the bleeder valve. I have cut open old rubber lines like these and some are completely blocked from age. When you apply the brakes there is high pressure to squeeze fluid through the restriction. But not enough return pressure because the brake shoe return springs are not strong enough to over come the resistance. Order all new rubber lines from Memphis or have a local hydraulic shop make new hoses for you.

 

[hendersond]

I'm concerned about driving the truck without the airpac. I would caution you about that. It is my understanding the airpac does 2 things. Increases the pressure and the VOLUME. The master may not push enough volume to effectively activate all 12 wheel cylinders.

 

[Brad]

Something to report, I think?
I was pretty much convinced that I had a bad rubber line at the drivers front wheel, and either a master cyl or air pac problem.
So just thisevening I did my "test" again in that I built up my air and applied the brakes. As usual, the front wheel lock up tite, to tite to move by hand. The other wheels were dragging, but moovable by one hand.
Here is what then happened. The truck sat an hour or two, the front wheel was now moovable but very tite, the others not as tite but still not free.
I had drained the air tank, the wheels were unchanged.
NOW, here is why I NOW think that the hose at the wheel is OK. I decided to remove the hose and cracked the metal lne where it ENTERS the the rubber line. It immediatly released, totally free. If the hose was bad would it not have still been locked up??
Now the other thing that convices me that the airpac is bad.
As I removed the exit line from the end of the air pac, AFTER cracking the front wheel line, it was apparent that there was pressure in the line at the end of the air pac. It spit and sputtered with pressure quite a bit. This tells me that the air pac is not allowing the line pressure to release?
Now as I said, I am not the brightest, but this makes sense to me. I hope I have described it well enough for you to get my meaning.
Now on another thought, since that front wheel seemed to be locking up much worse than the rest perhaps it is the rubber line between the chasis and the front axle?? But then why not both front wheels locking up the same???
Will this torment ever end??
Thanks to all in advance. Tell me if you agree or where I am going wrong?
I am ready to try the brakes bypassing the airpac, once I bleed them. I will be very careful and only trying will tell. But I am inclined to think there is not enough volumn pushed by the small master cyl???? We shall see???

 

[marchplumber]

Torment? Yes, it will come to an end, one way or the other. I find with a "can do" spirit, things seem to go a bit better. Whether they do or not, I don't know, but it sure seems that way! Attitude is a huge multiplier in any situation! Sounds like you might have "hit on something". Well worth further investigation! "Any thing worth having, is worth working for!" You have got a TON of you invested, I simply suggest seeing it through! IF after you get her fixed, you want to sell her, then you can do so with a clear heart, knowing you got the problem rectified before it became some one else es dilemma!

God bless and charge on!
Tony

 

[hendersond]

If you crack the line on the master it does not release the brake right???? Then I would think it was an airpack.

 

[Brad]

Wish me luck!! I am heading back out and try all the ideas I can.
Thanks, I will report in soon.

 

[Brad]

2:53PM
Just finished the air pac by-pass experiment.
There is no one around here to help so I had to draft my wife and her artificial knee to help me bleed, after installing a by-pass line. Bleed it all two times, some fittings 3 or 4 times and got out all the air I could. Also, kept adjusting the brakes as close as possible with-out drag so that it would take less volume of fluid if the cylinders were as extended as possible to start with. At least that was my thoughts.
Anyway I ended up with about a third pedal on the first push.
I took it all off the blocks and took a short spin until I get some more gas this afternoon.
At least I am able to tell that on gravel, I can slide a couple of the wheels, so I do have some brakes.
Soon as I get the gas I am going on the hardtop and will see what's up?
One thing it seems, nothing is dragging or locking up. So can I be correct in thinking my problem has been the air-pac??
Thanks as always.
Brad

 

[Brad]

OK, now had we the hard road test. Of course it leaves allot to be desired, but I can stop it purty reasonable. We have a local event next weekend and the truck will not have to leave town, so I think we'll be just fine for the parade. It all ahppens no more than a three mile round trip from here at Dad's house.
If I had to leave town it would be a different story.
But as far as the brake situation goes. I can get on them real hard and it will stop the truck. Better yet, when I try pulling out again, the brakes are FREE.
I am calling the re-builder tomorrow morning and see if he will hold to his word??

Now, just a word about "additude". Friend, I agree with you 110% about sticking with something like this. But you just are not aware that before this brake problem I spent three summers under this %@^&@! truck trying to get the so called "automatic" transmission to work in anything other than low range. Finally my Dad insisted that we pull the engine and tranny and install a different engine and tranny that he had that had been in an identical truck that had been converted by a local township.
Then of course there was all the other normal restotation work, etc.
Then Dad had his stroke and it is left to me to do all this happy work on this truck and everything else he owned around here, ie. backhoe, forklift, sawmill, kumber kiln, his car, the house, dealing with the VA regarding his situation. And my two wonderful brothers claim ignorance when it comes to anything mechanical (or sweat) around here.
So that is why I so very much appreciate everyones advice and assistance.
And so, thank you all, I really do appreciate any help you can give. I am not a truck mechanic, but I am trying.
Best to all,
Brad

 

[Heath_h49008]

That is the front running theory.

Something is allowing air to be retained in the major cylinder of the AirPack and holding residual pressure. Either the hydraulic side is hanging and sending the air there, or the air cannot vent properly after being applied.

I would guess that the brakes are simply adjusted tighter on one wheel than the others... so it "locks up" at a slightly lower pressure.

You're almost there!

 

[Brad]

Thanks to everyone!!
Maybe this will give an idea of what we been up to here?

 

[marchplumber]

I beg to differ Brad, you are well on your way to becoming a truck mechanic! CONGRATS! Way to keep chargin! You are to be commended Sir, along with all your fellow Steel Soldier members that gave advice and consul! My hat is off to ya!

God bless,
Tony

 

[Heath_h49008]

Indeed! Don't give up. It's something tiny, and when you have it licked you'll know darn well what you have accomplished.

 

[m1010plowboy]

Nice detail under the hood Brad and now I see the problem......the compressor is missing.

Thanks to everyone!!
Maybe this will give an idea of what we been up to here?View attachment 444984

 

[Brad]

Thanks to all for the kind words
I was just sending that photo to show the amount of work and TLC we put into this truck. These pics show my Son driving with my Dad, and other local vets, in better days. Ben was recently home from a year in Iraq.
It was may Dad's labor of love.
Before we started the restoration, he tried giving it to the local American Legion and VFW to restore to haul the vets in local parades and events, along with $1000 to get started. But they (very wisely) declined saying it was too much for them.
Then someone told a fella from another town about the truck and he tried buying it for a song, but Dad said we would do it ourselves. That was maybe five years ago and I been under that thing ever since.
It was allot of fun working with Dad on it but now that he us unable to even talk about it, it is nothing but a job. And everything on it is big and heavy, and hard. I am not in good shape myself and just getting up and down is hard for me.
But as long as I know what I'm doing I will keep at it. It's just when everything I do does not work. Then I feel I'm wasting my time.
I am going to call the airpac rebuilder now and see what he says.
Adios

 

[vtdeucedriver]

WOW that is a beautiful truck!!!! Stick with it!! If thats your dad in the passenger seat, he is lovin it and knows it! To me it sure sounded like the airpack. I dont own one but I have always had a soft spot for the M-135 so who knows, maybe one day I will own one. Anyhow I do own a bunch of 5 tons and the airpack does not like to sit for long periods. As you will find, the piston will hang up after a brake application and not retract there for release the brake. As mentioned before, either the air assisting is not releasing allowing the piston to retract or the piston itself is not. I cant say enough about keeping moisture out of the air system. You might be suprised if you remove the plug at the back of the pack, you might have water in there. I dont know if you have done that or not.

I am also not keen on the idea of using Dot 3 brake fluid. With these vehicles, dot 5 is the way to go.

Stick with it. You said that your not a large truck mechanic but guess what? These vehicles were designed and build so that your farm boy from PA could work on one and your doing exactly that. I can see in the few pics that you posted, your dad took lots of care restoring it.................I can only say thanks as now Im thinking about taking a ride out to a local farm that has one with a manure spreader on it. You got a nice original example, maybe one day I will find one.

 

[pa.rich]

Brad, I have been reading all the posts and looking at the pictures and I must say your dad did a great job on the paint job and the markings. I have a M211 which is same up front. I am glad you are making progress with the brake problem, and thanks for sharing about the truck and especially your dad. I hope he gets well. Sometimes stroke victims do recover greatly.Thanks for the posts, we can learn from it. Regards! Rich. I am on the other end of the state. Maybe some day we could get together.

 

[Brad]

Well friends, MAY HAVE RIGHT!!!
I got the airpac back from Precision Rebuilders who were quite honorable and went over it again, even after a year. But realizing that we really did not ever get the truck working since it came back the first time.
Anyway, they said they were unable to find a problem, but did again replace all the rubbers seals, etc.
Before we just re-installed it my Son and I loosened all the brake lines at the wheels and other places along the way, and blew them all out with air pressure. I cannot say that there was much if anything found in the lines. They seemed very clean, except for one place where my son said something came out and hit him. Otherwise clean as a whistle.
Anyway after that and re-installing the air pac, we took our time and bled everything just as directed in the TM. It tool allot of fluid to fill it all up again and NO air.
So the big moment came and I took it for a good run and HAD NO PROBLEMS!!!
I am not going to claim victory yet, I know how this stuff can haunt me. But so far, so good.
That was last week and I have not had a chance for another run, but maybe today I can. Lets hope.
I cannot thank everyone enough for the advice, etc. As much as the knowledge passed to me, I appreciate the encouragement. Much more problems, and I am whipped.
Thanks so much,
Brad Foust

 

[Brad]

Also, here I am again.
Hey Rich, thanks for the kind words.
Earlier this month my Son was able to run the truck in a small local parade. Only cause my Dad was able to attend and watch the parade. He ran it with the airpac bypassed.
Anyway, when my Dad saw it coming, in fact leading the parade, Dad started to tear up. He put allot of work and money in it and had only been able to ride in it one time, about a month before the stroke. He is not able to get in the truck. The only way we might get him in is in his wheel char in the bed. But he really could not tolerate a long ride.
I would get ride of the truck, Mom and he could use the money to help pay for his help. But he will not hear of it. And I understand, its the only thing he can really enjoy. Just seeing it, etc.
Thanks agai, if yer ever out this way dont hesitate to contact me.
724-235-1140.
Take care