Finally happened to me-no brakes

[JTugwell]

No Brakes. Thank God I found out at the pre-check rather than on the road. Ive done a search, and I have a good idea, but its a little sketchy. I wanted to get some opinions to make sure Im pointed in the right direction.

Ok the master cylinder was empty. This has happened before, but I was able to add fluid, and take off again. Now its time for some attention. This time even after adding fluid I have no pedal. bled it to the air pack, and still no pedal. after a search i found that seals in the air pack can give out causing the fluid to leak into the air side. I have done threads on here about oily residue coming out of my vent lines. maybe its brake fluid? its going somewhere, and i dont appear to have leaking wheel cylinders. Would it be safe to say i need to rebuild my air pack? maybe even replace the mc while im in there? ive also never messed with an air pack before. im mechanically inclined, and do all my own work. with that being said ive found rebuild kits for 130.00, and rebuilt units for 300.00. is it worth it to rebuild, or just get a rebuilt one?

 

[jwaller]

Ok the master cylinder was empty. This has happened before, but I was able to add fluid, and take off again.

this should have been your BIGGEST clue. your truck is telling you something is wrong.


brake fluid doesn't evaporate. it doesn't disappear. it leaves for a reason. YOU HAVE A LEAK!!!

fix it before you kill somebody.

 

[greenjeepster]

The air pack has nothing to do with the lack of fluid or brakes.... Even with a bad airpack your hydraulic brakes should be working.

Something else is wrong.

 

[JTugwell]

this should have been your BIGGEST clue. your truck is telling you something is wrong.


brake fluid doesn't evaporate. it doesn't disappear. it leaves for a reason. YOU HAVE A LEAK!!!

fix it before you kill somebody.

i know i have a leak. hence the post. also i never said i was going to, or have any intention of driving it like it is. i obviously do a pre check before i drive it anywhere, or i wouldnt have noticed it until it was on the road. what you quoted me in saying was merely an observation by myself. the truck isnt that old to me, and i had lost a little fluid when converting the brake switch to air. i dont want to derail this anymore. the truck sat for a month or so, now all my fluid is gone. im not gonna drive it, start it, move it, think about moving it, have a dream about driving it ect.

 

[JTugwell]

The air pack has nothing to do with the lack of fluid or brakes.... Even with a bad airpack your hydraulic brakes should be working.

Something else is wrong.

cool thanks for the info. i though i saw a post where a seal could go bad or something, and leak into the pack. i noticed some oily residue on the hood, and firewall around the vent line which was the reason for my suspicion. ill have to go out there, and go through the motions again. this is something i want to be right. thanks again.

 

[greenjeepster]

Refill the master cylinder and start the truck up. Pump the brakes until you think you can't pump anymore then keep pumping them.... If you have no pedal after 15 minutes or so of pumping check your fluid and see if it went down.

 

[JTugwell]

alright ill go out there, and check that here in a few. thanks.

 

[ASTFU]

I had fluid disapearing and I checked all the cylinders, it was leaking in the airpack I replaced the pack with a rebuilt one and have had no problems with fluid loss. check your vent lines for fluid.

 

[73X]

I tend to agree with check the airpack they do leak.

 

[73X]

this should have been your BIGGEST clue. your truck is telling you something is wrong.


brake fluid doesn't evaporate. it doesn't disappear. it leaves for a reason. YOU HAVE A LEAK!!!

fix it before you kill somebody.

Now this is a useful response. I think he already knows something is wrong. Hence the request for help. Sorry OP. for the rant

 

[roger-wilco-66]

I had the same problem, brake fluid leaking out of the airpack vent line. Sometimes it pays to have a look under the hood! I immediatly changed the airpack against a rebuild unit. I first wanted to repair the old one, but the new one was only slightly more expensive than the kit.
After the change everything was fine. If I was you I would have a close look at the MBC when you change the airpack. If it shows signs of corrosion in the inside, I would not hesitate to put a new unit in, just for peace of mind and while your at it anyway.

Cheers,
Mark

 

[JTugwell]

i posted a thread a while ago about an oily film everywhere. firewall, hood, ect. didnt really get any feedback. this makes sense though. its got to be brake fluid. well that explains it. looks like im changing an air pack, and yes if there is any question whatsoever about the master ill be changing that too.

 

[JTugwell]

Now this is a useful response. I think he already knows something is wrong. Hence the request for help. Sorry OP. for the rant

i think some people just see brakes in a post and flip out. you could start off with "i went to autozone and bought some brake pads for my wife's blazer"

YOU'RE GONNA KILL SOMEBODY!!! 14000 LBS!!!

 

[NRG]

i think some people just see brakes in a post and flip out. You could start off with "i went to autozone and bought some brake pads for my wife's blazer"

you're gonna kill somebody!!! 14000 lbs!!!

lol

 

[Somemedic]

I can hear the voice of Sherriff John Burnell now:

"He was hopped up on a lethal concoction of methaamphetamine and antifreeze. Couple that with bad brakes and he was 7 tons rolling death..."

lol

 

[Keith_J]

I have found the majority of leaking wheel cylinders to be inferior cup return springs. These springs are 1" in diameter, without cup expanders on the ends. This makes the sealing cups weep. Since there are 24 sealing cups, it doesn't take much of a leak to drain the master cylinder.

$6.50 per wheel, 20 seconds of honing and you are golden. But yeah, it is a lot of work. So focus on the wheels with wet backing plates at the 6:00 position.

 

[derby]

I also agree, check the air pack. I would also pull your inspection covers on the drums. Take a peek in there and see if the shoes are greasy looking. You could have one or more wheel cylinders leaking also. just another thought ,check your rubber flex lines while you are at it they might not be leaking but could be ready for replacement.

 

[JTugwell]

thanks everybody for the responses. i think im gonna go grab some more jack stands, and just take all the wheels off the truck. probably go through everything while im there. wheel cylinders, lines, ect. ive been wanting to paint it, so until i find an air pack may as well do something constructive with it. hopefully ill find/get one soon. its starting to warm up here, and im itching to drive it.

 

[swbradley1]

Let us know what you find. I have one with no brakes on it now and could use any insight to what the problem is.

sw

 

[Scarecrow1]

I'm sure that the problem will be as fore mentioned lines seals or airpack ...I would try the airpack first ...and so on and so on ... I have the habit of when in doubt start replacing the most likely and keep going untill it's all new or working like new .... I had a car the would at times develope phantom problems withe the breaks ...Sometimes it had a problem and some time they were perfectly fine each time it seemed like it could be one thing and then another ...So I started with the booster and finished with the pads . The only thing I didnt change was the lines ..When it comes to breaks if in doubt tear it all out and start over .......