I bleed my brakes today, it was a massive, massive improvement, but I still have a bit of a problem.

The first time I use the brakes the pedal hits the floor, the second time it doesn't, stays about 2" away and every other pump is the same. It will hit the floor if I give it about 5 seconds, with the pedal up or down, makes no difference.

Now this seems like air, the problem is I can't seem to find it. Maybe it's something else, I dunno.

I bleed and re-bleed the brakes. The first time I had done all four it got me to where I am now, but after I went and did it again I noticed no improvement or change. The fluid flows clean from all 4, no bubbles, nadda, just nice and clean. I did it about 3 times on each and still found nothing (about 3-4 oz's of oil). Smacked the MC with a mallet a bit too...

Also I am noticing a sound coming from underneath, seems to be coming from more than one spot, kinda sounds like (sorry for being gross) when you push spit through your teeth with your tongue, lol. However it does this on every pump, not just the first. I'm not sure if it's a tiny amount of air or if it's just the sound made when it goes around anywhere the line has a fixture on it. All the fixtures where tight and sealed.


If it is air, how can I get it out if it's not showing up when I bleed? Any other possibilities?

 

Rebuild the Master Cylinder don't smack it. It's not hard and will reveal a hard pedal.

 

Not so much being hard as being too soft the first time. It seems to be how it should after the first pump, which again leads me to think a tiny bit of air somewhere.

Currently don't have time to rebuild it, lol and besides I'd put in a Dual MC instead lol

 

did you bleed the master itself, also check the brake adjustment. if there's air in the system you would feel a little pedal sinking. pump the pedal then hold it (for about 1 min), does the pedal seem to slowly sink (still has air). pump the pedal and hold it (for a few seconds) and note how high the pedal is, release the pedal, push and hold the pedal again (1 push, no pumping)....is it a lot lower, if so check brake adjustment.

 

Didn't bleed the MC, didn't see where to be honest, I'll go check. and get back to you...

 

Ok, ran both tests. On the first with pumping and holding for a minute there wasn't much change. Maybe 1/8-1/4" drop but how hard I pressed down effected the measurement a bit, so it could just be from that (and I did hard enough it's killing my leg now)

On the second test, to pump and hold then release and put down again I noticed more of a drop... so how do I check the brake adjustment?

And a quick google check tells me "holy crap thats a lot of work right now"


I should note on the first time I use the pedal, there is restitance, it just manages to travel farther, it feels the same I can just hit the floor the first time.

 

Alright, make this easy. Here is a video showing it. As you can see the pedal has pressure on the way down, but not till the second pump does it stay up.


Part of me hopes it's just a bit of air, it's a real chore getting those back wheels off...

 

Bench bleeding

 

Well crap, just discovered for whatever reason now I don't have any lights, head lights, tail lights, turn signals, whatever. Awesome.

Now to find the fuse box...

SSDD...

 

most of the pedal height is from the front brake adjustment (assuming it's still drums).

 

I agree, check your brake adjustment at the wheels. If they're loose, the springs will pull the shoes back too far from the drums, so when you hit the pedal the first time, they have to travel farther than subsequent pumps. It is a common problem.

Does that sound you describe seem to come from the master cylinder? Disconnecting the lines from the m/c and hooking up a small line as shown in the pics above will bleed the m/c, then you get to start the whole process over again. It is an important step commonly overlooked.

 

also on yours (stock set up) you'll need to hook 2 brake lines up to the block. you can either run the line back into the master (like the pics) or you can run them into a glass jar under the master and slowly push the brake pedal until no more air bubbles. the glass jar technique is easier with 2 people (since the master is under the truck). get a glass jar (mine was for pickles ), fill it a little about 1/4 full with new brake fluid, run the lines from the master almost to the bottom of the jar and start pumping.......you'll need to check the master level every few pumps. hook everything back up and recheck (you might need to re-bleed the system again).

but i would check the front brake adjustment first. jack up one front tire and spin it, how many rotations does it take to stop (maybe mark the wheel), if you want to get a higher pedal then maybe 1 1/2 - 2 tire rotations.

 

Thanks guys, I'll give bleeding the MC a shot. I didn't think it needed to be done if the MC wasn't replaced.

It's not so much the height of the pedal, it's just more like it doesn't kick in the first time really. It sorta does, I moved the truck a little and was able to stop it once it hit the floor, but it doesn't really grab like it does on a second pump. I'm not sure on the bleeding of it though, that MC looks nothing like mine... in the slightest, lol.

I'm hoping it's the MC. Removing those rear wheels is a bit of a chore, granite I've done one side so they should come off easy, but I haven't the other...

Anyone have any links or info on adjusting the brake allignment?


On the bright side it did seem to drive (well back and forth a few feet) pretty nicely, not being stuck in ultra super low seemed to help, lol.

And I also discovered i have to flip the breaker or whatever for my head lights, I think when I tried to use the 2-speed switch it flip it (heard a click in the dash)... and then I have to check it all out because after a quick look on an added on fuse in the line I discovered the fuse was actually half a bolt...



...just want to drive it right now... just a little, lol

 

You shouldn't have to remove the wheels to adjust the brakes. Your giant truck stuff may be a bit different than what I'm used to, in more conventional vehicle settings, but hopefully there will be a small plug to remove at the bottom of the back side of the brake backing plate. Remove that plug and you'll gain access to the adjuster star wheel. Raise the wheels off the ground and spin the wheel. You should have a very slight drag on them from the brake shoes. Tighten the little adjuster wheel until you have that drag. Then try your pedal again and see what happens.

 

Oops! Thought you had a new mc. Sorry.