No pedal after bleeding air pack in M35A2

[Crestonean]

I lubricated the air pack last week, took a test drive and the brakes were strong with no issues. I pushed the pedal when I pulled in the driveway and it hit the floor. The driver's front line blew right there (whew). It was almost new. I replaced it today, checked the wheel cylinder and repacked the bearings, and started bleeding at the air pack, even though I wasn't sure it was necessary with just one front line replaced. The fluid in the bottle was clear the second time the wife pushed the pedal. I closed the bleeder valve, and now have no pedal at all.

I don't know what to try from here. I've studied my hard copies of the TM's in 3" binders, and reviewed many, many posts on brake bleeding and problems, but I could use some help. I've had this truck for 18 months now, and it has been trouble-free. The brakes and bearings are like new - fresh lines and clean grease.

Thanks for any tips!

 

[Big Dumb Truck]

It sounds like you have a lot of air in the lines. You should top off the master cylinder and bleed all of the wheel cylinders. Also look for other leaks. It can't hurt.

 

[Rmtaunton]

I agree when you blew that line you sucked up lots of air I would bleed all of them and glad it happened in driveway ,, whew

 

[73m819]

IF you lost ONE hose, REPLACE ALL FIVE because they are all the same age.

 

[rchalmers3]

I'm not saying it's the case, but I have had the experience of having a master cylinder fail on me during the bleeding process. Pumping the master cylinder out of it's normal operating range can cause the internal seals to fail, due to trash in the bore or pitted surfaces.

Rick

 

[Crestonean]

Thanks for the help - I'll be bleeding all the lines tomorrow. I had heard about master cylinders failing when the pedal gets pushed to the floor during bleeding, so I'll keep my fingers crossed.

I appreciate the responses. This is the first time I've been inside a brake drum for many years. I was feeling good about getting everything back together, despite a long bruise on my bicep from getting pinched between the drum and the backing plate. If I wasn't 60 miles from the nearest town, I'd ask for help.

Thanks again

 

[LiveFreeOrDieTryn2B]

Have you checked or replaced wheel cylinder's and your hard lines if you have any rust or sludge in brake fluid, you should rebuild/ replace. The hard lines will rust from the inside out.

 

[rustystud]

IF you lost ONE hose, REPLACE ALL FIVE because they are all the same age.

This is really good advice ! I would say buy from Peashooter but he is no longer selling them ( Aaron help us, we need you ! ). You can have them made for you. Peashooter left all the dimensions on his brake post (page) .

 

[LiveFreeOrDieTryn2B]

Also out of curiosity did you use tool oil or grease in air pack I used grease in mine as that's what was in mine when I rebuilt it not one lick of rust in the air cylinder I used red high temp grease and not one problem only rebuilt for safety reasons as I rebuilt whole system.

 

[Welder1]

Peashooter will still make flex lines but only by request. He told me supplier was unreliable on delivery and he had to refund money because of delay. I just bought a set recently and got them in about a week. They looked great so if you need some give him a shout I think he will help you out he did me. Thanks Peashooter.



Eddie Cannon

 

[Crestonean]

Also out of curiosity did you use tool oil or grease in air pack I used grease in mine as that's what was in mine when I rebuilt it not one lick of rust in the air cylinder I used red high temp grease and not one problem only rebuilt for safety reasons as I rebuilt whole system.

I used air tool oil, since it was what I'd seen recommended here. I hadn't heard of using high temp grease, but it sounds like it works great if I end up rebuilding the air pack. Thanks.

I'll be back at it this afternoon, but keep wondering why the fluid level in the master cylinder doesn't draw down with the bleeding. Maybe an airlock somewhere. These brakes were working fine last week.

 

[bonedoc]

Peashooter will still make flex lines but only by request. He told me supplier was unreliable on delivery and he had to refund money because of delay. I just bought a set recently and got them in about a week. They looked great so if you need some give him a shout I think he will help you out he did me. Thanks Peashooter.



Eddie Cannon

This is correct. I recently got my lines, all of them, hard lines and flex lines from him. He told me that due to supplier reliability as well as his own time he could do it as long as I didn't need them yesterday. If you have the time and can give him the time you won't be disappointed. Drop him a line
Thanks very much Peashooter....appreciate everything.

 

[bonedoc]

You may want to consider building a pressure bleeder. You can then bleed the system and eliminate the risk of sucking air back in or over pumping the master cylinder. They are relatively cheap to build and will be an item you will use time and time again. There are many threads on how to construct one.
I agree with the others...you probably still have more air in the lines. If you suspect your master cylinder is bad....or even on its way out I bought one a few months ago off Clintogf on the forum here. Great price and it worked great.

 

[bigmike]

Yep, you've got air in the system.
1) build a brake bleeder (pays for itself everytime I use it)
2) bleed airpack first, then go thru all cylinders bleeding thoroughly to insure no air.
3) Drive with confidence that you've gone thru your break system thoroughly.

 

[Monkeyboyarmy]

I would bet money that the piston in the master cylinder is not returning all the way. That piston has to be all the way back before the ports open up to draw fluid. Slide the boot back and see if the piston is back against the washer and clip.

 

[Crestonean]

I would bet money that the piston in the master cylinder is not returning all the way. That piston has to be all the way back before the ports open up to draw fluid. Slide the boot back and see if the piston is back against the washer and clip.

Thanks - on my way out to check now. Next step is building a power bleeder.

 

[73m819]

Yep, you've got air in the system.
1) build a brake bleeder (pays for itself everytime I use it)
2) bleed airpack first, then go thru all cylinders bleeding thoroughly to insure no air.
3) Drive with confidence that you've gone thru your break system thoroughly.

BLEED MC FIRST then air pack, then #3 axle, left first, right second, then #2 axle, left first, right second, then #1 axle the right wheel, then the left, ( this is the bleeding order for the wheels for a 5t, not sure on the deuce)

 

[m715mike]

BLEED MC FIRST then air pack, then #3 axle, left first, right second, then #2 axle, left first, right second, then #1 axle the right wheel, then the left, ( this is the bleeding order for the wheels for a 5t, not sure on the deuce)

I believe the Deuce is a bit different.

Please see the information in this thread:
http://www.steelsoldiers.com/showthread.php?140605-Bleeding-Brakes-after-Wheel-Cylinder-Replacement



Here is a good link for a power bleeder:
http://www.steelsoldiers.com/showthread.php?3229-Deuce-Power-Bleeder-R4x4-Style

 

[73m819]

I would bet money that the piston in the master cylinder is not returning all the way. That piston has to be all the way back before the ports open up to draw fluid. Slide the boot back and see if the piston is back against the washer and clip.

If he had brakes BEFORE he blew the line, I doubt that the MC is the issue, same with the air pack, he said right here in the thread "second time pressure build, only fluid came out so I tightened things down" THIS TELLS the problem, there is NO way that air was gotten out of the system as the op stated his bleeding process. the OP needs to bleed the system in the correct order, THEN wait over night THEN bleed the system AGAIN

 

[73m819]

I believe the Deuce is a bit different.

Please see the information in this thread:
http://www.steelsoldiers.com/showthread.php?140605-Bleeding-Brakes-after-Wheel-Cylinder-Replacement



Here is a good link for a power bleeder:
http://www.steelsoldiers.com/showthread.php?3229-Deuce-Power-Bleeder-R4x4-Style

Mike, he still needs to bleed the system in the CORRECT order, no matter what that order, if he wants safe brakes, I posted the 5t order so he could see that there IS a CORRECT order for brake bleeding.