Another noob brake question, I searched...

[pwerwagn]

Hi guys,

I have a brake question, and I'm sure its been covered here before but in days of searching I have one symptom that I have not seen anywhere.

So when I bought this deuce, I knew it had brake issues. Supposedly they rebuilt the airpack, they gave the the instructions and all the old parts, doesn't mean they did it right though. It had a leak on a gasket on the airpack when I got it. They told me for a while now, the pedal has been solid, but zero brakes. The truck is currently in a storage facility, without room to load on a trailer to bring it home. There is a steep downhill out of the facility, so I kind of need brakes just to get it out and onto the trailer. The parking brake sucks too.

After I bought it, I went and started it and I noticed the brakes went to the floor. I fixed the leak on the airpack, pulled the MC cap, and it was dry. I refilled with dot5. I pumped the brakes a little (by hand) and every time I would pump them, a some air bubbles would come up. So the little return hole didn't seem to be plugged in the MC, although like an idiot I didn't look while it was dry.

Here's where it got weird, that I haven't seen mentioned anywhere. After doing this about 5 times, the MC started spraying brake fluid out of it like a geyser. All the way up to the roof. It sprayed a solid stream of brake fluid up for at least 30 seconds, it made a huge mess.

I refilled the MC, pumped it again (this time prepared to cover the MC if it turned into ole faithful). Now the pedal is solid, firm...and doesn't actuate anything.

I'm going back down tonight to mess with it a bit. I am going to put some oil in the airpack, check the holes in the MC, etc. Anything else I can check to nail this down?

I also have a short airpack, unknown condition. The truck has the long one. Which one is better to rebuild and more reliable?

I need to get this thing out of the storage facility and about a half a mile down a dirt road to get it on my trailer. Has anyone ever bypassed the airpack to get un-assisted brakes for a situation like this?

Thanks for you time, I really appreciate it.

--Jeff

 

[Kaiser67M715]

How are you bleeding the system? Super easy to make a pressure bleeder, then bleed air pack, the the rears, moving closer to master cylinder.

As a last resort and only temporary, I would make a new line from master and use an in line adapter to connect to the out of the air pack, this will bypass the air pack as a failure source. You will have brakes, but it will require lots of force. You will want to resist the urge to go faster the 15mph.


I don't think one air pack is better then the other, but last I knew the rebuild kit for a short pack was twice as much. And harder to find.


Sent from my SM-S920L using Tapatalk

 

[someoldmoose]

Hi ! This is exactly what is happening with my M820 except that my brakes DO work when bled. I was confused because an entire m/c full of fluid disappeared while it was sitting for a year and no signs of any leaks at w/c s, hoses, lines, anywhere. I asked and was told to change the air-pac. I will pass this advice on to you as it came from a source on here that I trust ( 98G ). I am currently saving my pennies to buy one AND a rebuild kit for the one I replace ( gotta have spares in this hobby ).

As for the geyser of brake fluid . . . complettely normal. Mine didn't hit the roof but yeah. The bubbles you had first was the return side of the m/c bleeding itself internally. Once bled, whoosh, Old DOT 5 Geyser. The hard pedal, no brakes also leads me to believe your booster is bad. Air / hydraulic brakes are weird aminals. Sounds like the m/c is doing it's job sending fluid to the booster but then it's not being sent on to the rest of the system.

My advice only ; DO NOT MOVE THAT THING UNLESS SOMETHING ELSE CAN CONTROL IT'S MOVEMENT. This is how that ended up for me. ( Full story in a different thread )



$ 500 later it's back on the stone area. It won't be moving again until it has a new booster and m/c. Just my $ .02 based on recent experience. Your actual mileage may vary. Happy Motoring !

 

[WillWagner]

sounds like a plugged hole in the MC or a swolen rubber cup in the MC. A word of advice, stay AWAY from the New Star or whatever they are calling it no line of rebuild kits, stay away from ALL Chinese made stuff, the rubber swells very fast and you will be doing the job again

 

[73m819]

Hi guys,

I have a brake question, and I'm sure its been covered here before but in days of searching I have one symptom that I have not seen anywhere.

So when I bought this deuce, I knew it had brake issues. Supposedly they rebuilt the airpack, they gave the the instructions and all the old parts, doesn't mean they did it right though. It had a leak on a gasket on the airpack when I got it. They told me for a while now, the pedal has been solid, but zero brakes. The truck is currently in a storage facility, without room to load on a trailer to bring it home. There is a steep downhill out of the facility, so I kind of need brakes just to get it out and onto the trailer. The parking brake sucks too.

After I bought it, I went and started it and I noticed the brakes went to the floor. I fixed the leak on the airpack, pulled the MC cap, and it was dry. I refilled with dot5. I pumped the brakes a little (by hand) and every time I would pump them, a some air bubbles would come up. So the little return hole didn't seem to be plugged in the MC, although like an idiot I didn't look while it was dry.

Here's where it got weird, that I haven't seen mentioned anywhere. After doing this about 5 times, the MC started spraying brake fluid out of it like a geyser. All the way up to the roof. It sprayed a solid stream of brake fluid up for at least 30 seconds, it made a huge mess.

I refilled the MC, pumped it again (this time prepared to cover the MC if it turned into ole faithful). Now the pedal is solid, firm...and doesn't actuate anything.

I'm going back down tonight to mess with it a bit. I am going to put some oil in the airpack, check the holes in the MC, etc. Anything else I can check to nail this down?

I also have a short airpack, unknown condition. The truck has the long one. Which one is better to rebuild and more reliable?

I need to get this thing out of the storage facility and about a half a mile down a dirt road to get it on my trailer. Has anyone ever bypassed the airpack to get un-assisted brakes for a situation like this?

Thanks for you time, I really appreciate it.

--Jeff

I do NOT see anywhere that you mentioned BLEEDING the brakes in the above post, if so all you are doing is compressing air which does not do much for a juice brake system, BEFORE you do ANYTHING, bleed the brakes, there is NO way to know if anything is wrong, let alone fix it, without the system being air free, if you cannot get it air free, then find out why, fix that issue, then keep going with the bleeding till the system is bled of all air. Then and only then can you deal with other issues. After each time you open the system, REBLEED.

 

[pwerwagn]

As a last resort and only temporary, I would make a new line from master and use an in line adapter to connect to the out of the air pack, this will bypass the air pack as a failure source. You will have brakes, but it will require lots of force. You will want to resist the urge to go faster the 15mph.
Sent from my SM-S920L using Tapatalk

This is actually what I ended up doing. I re-bled the brakes when I got down there (I have a snap on air bleeder that I made work), and the pedal would pump up solid as a rock. I removed the J tube on back of the airpack and squirted some tool oil in it, and the air pack started trying to work...sort-of. But it was still questionable at best, sometimes the pedal would actuate the brakes, other times it was solid as a rock with zero brakes.

I took a box of fittings, lines, etc that I had...built a line to bypass the airpack and the brakes worked fine then. They actually weren't too bad at all without the air assist.

I'll rebuild the air pack, and go from there now. Time to build a hitch on back and do some maintenance, and then haul it back down to the lake for a recovery vehicle.

thanks for all the help,
Jeff

 

[pwerwagn]

Just to close this out, as I hate posts that never have resolution...

I tore my airpack apart and all the parts in it looked really good. The owner I bought it from claimed to have rebuilt it, well he did...just wrong. The cylinder was also really crapped up. I ordered a kit, but it took forever to get in so re-assembled it all with the stuff that was in it. Honed the cylinder with a cylinder hone (not a wheel cyl hone), cleaned everything up really good. I used RTV where I tore gaskets.

I put it on the truck and right away even without air, the brakes worked fine (just like they did with the airpack bypassed, obviously). I fixed the second air leak, power bled the brakes a few times again...and now the brakes work great. I also bought a spare master cyl and rebuild kit for that, and 6 wheel cyl rebuild kits and some other odd's n end's.

Thanks for all the help trouble shooting.

-Jeff

 

[russojap]

My advice only ; DO NOT MOVE THAT THING UNLESS SOMETHING ELSE CAN CONTROL IT'S MOVEMENT. This is how that ended up for me. ( Full story in a different thread )

View attachment 734473View attachment 734474View attachment 734475

$ 500 later it's back on the stone area. It won't be moving again until it has a new booster and m/c. Just my $ .02 based on recent experience. Your actual mileage may vary. Happy Motoring !

It cost $500.00 just to pull it back onto the gravel? I'm guessing it had to travel about 20 feet maybe , $25.00 per foot, is that the absolute best deal you could find?
It wouldn't drive out?