Brake Bleeding w/ Remote Master Cylender

[frank8003]

I was asked about DOT3 and DOT5 and do not mix
I have a lot of horrible terrible stories about that in here someplace but here is the "TM"

 

[jimm1009]

So I failed to read 100% of the information here and deserve three days in the electric chair for the offense! lol

I bled the brakes on my M35A2 due to all new wheel cylinders and flex hoses and brake shoes, etc.
I did not gravity bleed the wet side of the air pack first and had my "soldier 2" pump the brake pedal by mistake.
My question is Did I damage the airpack b y doing this?
I had her pump all of the pedal for bleeding all of the cylinders which is not the best way of doing things and I did not have shop air on the brake system at the emergency glad hand area.
I let the fluid sit overnight with the remote reservoir topped off so I will go back and gravity bleed the airpack tonight after 24 hours of rest to the brake system. I guess that I will then bleed them using a pressure pot after that.
jimm1009

 

[cattlerepairman]

No, you did not damage the air pack. You "can" bleed the brakes the way you described (no brake air pressure) because it is a hydraulic system after all and there is a mechanical connection between the brake pedal and the master cylinder. However, given the length of the lines and potential air traps, it is not considered to be the most effective/efficient method. You gave your spouse a good thigh workout for which she is surely grateful!
A quick re-bleed under pressure is advisable.
Compare the pedal feel you have now to the feel after the re-bleed. I think you will know right away what I mean.

 

[frank8003]

To play with brakes quietly with engine not running, not needed, hook up dry air compessor
air to the right rear glad hand from more or less remote compressor.
Makes it all easy and quite and can find every air leak that way.
Use the one man pressure bleeder hose form NAPA and a pressure feed reservoir like in my photos.
If you have a remote reservoir and/or use a pressure bleeder should take the advice of rosscommon page two and remove the splash plate in the master cylinder next time your in there, it all works better then.

Just read and understand all here in SS and don't need the electric chair, that is for the crazies.

 

[jimm1009]

To play with brakes quietly with engine not running, not needed, hook up dry air compessor
air to the right rear glad hand from more or less remote compressor.
Makes it all easy and quite and can find every air leak that way.
Use the one man pressure bleeder hose form NAPA and a pressure feed reservoir like in my photos.
If you have a remote reservoir and/or use a pressure bleeder should take the advice of rosscommon page two and remove the splash plate in the master cylinder next time your in there, it all works better then.

Just read and understand all here in SS and don't need the electric chair, that is for the crazies.

But are we not all slightly crazy for owning one of these big trucks? lol Jim

 

[cattlerepairman]

But are we not all slightly crazy for owning one of these big trucks? lol Jim

Absolutely. Not. There is always a 5 ton and an MTVR or a HEMTT! Now THAT would possibly be crazy!

 

[frank8003]

There is a TM to remove DOT 3 and change to DOT 5. It exists right here in SS
Now I can't find it
I know it is in here
Anybody know which TM that is?

 

[cattlerepairman]

There is a TM to remove DOT 3 and change to DOT 5. It exists right here in SS
Now I can't find it
I know it is in here
Anybody know which TM that is?

TB 43-0002-87 DEPARTMENT OF THE ARMY TECHNICAL BULLETIN
BRAKE FLUID, SILICONE (BFS) CONVERSION PROCEDURES FOR TANK-AUTOMOTIVE EQUIPMENT

https://www.steelsoldiers.com/upload/M35/TB43-0002-87.pdf

 

[frank8003]

DOT 3 to DOT 5

 

[jimm1009]

Well after bleeding my brakes following the replacement of all the wheel cylinders and flex hoses I have less than comfortable peal feel. I was going to drive it cautiously around the block to burn the fuzz off the new brake shoes and get a feel for the general condition and 24 hours after having it running and checking the lights, etc. I have none. No power to the flasher for some reason. That is discouraging but the reason for the newest post.
I have heard of the Motive brand pressure bleeder but also heard that is there is air in the same chamber of the bleeder as the fluid then you are wasting time trying to bleed due to the introduction of air into the fluid. I am used to using a pressure pot in the aviation industry that does have a diaphragm in the device but those are very expensive.
Suction type bleeding I am not a fan of due to leaks around the bleeder screws when they are loosened for bleeding. I would even rent a good one if there was such a rental tool but am not aware of one. What I did what go to a very popular lumber store with a blue sign and purchase a $25 pump up style weed sprayer and I have run about 6 small bottles of DOT 5 through it's veins.
It seems that I either still do not have enough fluid pushed through to evacuate the air or I introduced air into the fluid by using the pump-up device.
Each port was bled until there was no air for about 30 seconds but this is getting expensive at $10 for a standard size bottle of DOT 5.
Am about to give up and go ahead and rebuild my master cylinder since I have a kit for it and then go to DOT 3 and pressure bleeding.
Two reasons; cost of fluid and I have also read that a perfect brake system with no air but using Dot 5 can still not feel as "tight" as one with DOT 3 or 4.
jimm1009

aka, Jim

 

[cattlerepairman]

I assume you adjusted the brakes after you replaced the wheel cylinders? There is not a whole lot of fluid in the system and brakes even mildly out of adjustment can extend piston travel in the wheel cylinders to the point of a low pedal.

 

[jimm1009]

I assume you adjusted the brakes after you replaced the wheel cylinders? There is not a whole lot of fluid in the system and brakes even mildly out of adjustment can extend piston travel in the wheel cylinders to the point of a low pedal.

Yes I did. I installed new shoes on both rear axles and removed and cleaned all backing plates and brake components, etc. Front shoes were at 10% or less usage. Front shoes removed and cleaned and put back in same position.
Did major adjustment. Going to put about 20 miles on it and do another major adjustment after fuzz and burrs worn off new shoes.
Will bleed again too but would like this to be the last time for a year or so. Moderate climate in Louisville, KY area.
My fear is that I may have air contamination in fluid since it is not a manufactured Pressure Pot designed for bleeding.
I was very careful to keep my device in plenty of fluid.

 

[Mullaney]

Yes I did. I installed new shoes on both rear axles and removed and cleaned all backing plates and brake components, etc. Front shoes were at 10% or less usage. Front shoes removed and cleaned and put back in same position.
Did major adjustment. Going to put about 20 miles on it and do another major adjustment after fuzz and burrs worn off new shoes.
Will bleed again too but would like this to be the last time for a year or so. Moderate climate in Louisville, KY area.
My fear is that I may have air contamination in fluid since it is not a manufactured Pressure Pot designed for bleeding.
I was very careful to keep my device in plenty of fluid.

.
The bug sprayer bleeder is pretty good if you don't "cheap out" and introduce air. Your 5 can plan should have been enough if you kept the bleeder upright. When you adjusted the brake shoes, the cam at the bottom of the shoe need to also be free and rotated to .020 (from memory)

More information is in this book:
SMARPI9-2320-209-14P
also known as
SMI 9-2320-209-14&P

If you can't find it, let me know.

 

[jimm1009]

Actually the TM says .010 on the bottom but I went .012. On top I went to .020 but this is due to brand new shoes that have small burrs and fuzz on them. after the 15 to 20 miles with braking I will do the brake adjustment all over from scratch with shoes that area now trued out. I did keep 5 to 6 cans of fluid in the bug sprayer so as to keep the chance of air bubbles waaaaaay down.
jimm1009

 

[kendelrio]

P.S. to the thread:

We had a great thread on this some years back concerning bought -vs- built one man bleeding systems.

You can find it here.

Always great info in the site!

 

[frank8003]

The wheel cylinders are like the low points in the entire system
and will get goobered up. Wwhy not just use DOT 5.

 

[jimm1009]

I was only thinking about the DOT 5 fluid having some ability to be compressed as stated earlier in this thread. If we could put water in the brake system with no measurable compressibility that would give us the firmest feeling brake possible but of course that is not the correct fluid for obvious reasons. That is the only reason that I considered 3. I just want the firmest, sharpest brakes with the least amount of pedal travel possible. I know that it is not a $200,000 European car but I want those brakes! lol
I have no real reason to change fluids other than making them more firm. Still on the fence with the fluid change but I bleed my brakes each year
no matter what kind of fluid is flowing through the veins. Of course the gallon jug of DOT 5 initial cost is something that makes my gears squeak a little more too.
I sincerely appreciate all the opinions and the wealth of information here in this thread and the many others that I have participated in since 2004. All I can say is "think olive drab !"
jimm1009