Gravity bleeding the brakes???

[kaptnkaos]

Hey Guys,

I'm finally getting around to replacing the master cylinder on my '68 CS.
I know how to bench bleed the MC...
I am also going to have to bleed and adjust the rest of the system.
Can someone give me a run down on the gravity bleeding process...
I mean I basically know how it works, but do I do one wheel at a time or all 4 wheels or just 2 ???
Should I bleed first, or do I adjust first ???
I don't have any problem adjusting the front wheels (tighten the adjuster until you feel the drag on the hub, then back it of just until the drag goes away).
How do I tell when the rear wheels are adjusted right ??? I have always had a problem with that.

Thanks again...
KaptnKA S

[CO684X4]

I would start with getting the brakes adjusted first. You do the rears the same way as the front. Put the truck in Neutral and it will make it easier to spin them, Then I would re-bleed the master once you get it in the truck. Then go and gravity bleed all the wheels cyl. starting with the Passenger Rear then go Driver Rear then Passenger Front then Drivers Front. Then I would have someone help you pressure bleed all the wheels cyl. again. Once you get all the air out of the system. Rear adjust the brakes front and rear. Then you should be good to go.

[fordman]

i was told you open all four of them and let them bleed at the same time. i have done it once and it worked. but i still like pumping and holding the brakes better.

[kaptnkaos]

Yeah, I'm a little confused with the whole process...

I normally can't find someone to help when I need ta do something loke that especially since my buddy Kyle moved to Texas.
We used to help each other a lot with mechanical projects.

I'm not gonna get to do it this weekend any way.
I ordered a MC from NAPA and went to pick it up after work yesterday and ended up sending it back.
Someone had cross threaded the brass fitting and the threads were all buggered up, the replacement won't be in until Monday.
Oh well, I always have some thing to do...

KaptnKA S

[Bullitt390]

You can always get speed-bleeders, available in the HELP! section of Checker and Auto Zone. About $8 for two. Tremendously easy one man brake bleeding.

If you do not want to go that route NAPA has a self-bleeder kit, basically some clear tubing with a check valve in the middle to prevent fluid/ air returing into the caliper.

Josh

[kaptnkaos]

I have always used the two person method... but have heard about gravity bleeding.
I'm just not sure what the correct proceedure is.
I don't know anyone near by, that is available to help me, so the one person gravity bleeding sounded like a good idea.
I bought one of the pump bleeders from HF.. it didn't work worth a darn.
I really should replace the front wheel cylinders, when I rebuilt the brakes a while back, I put new ones on the back, but ended up putting rebuild kits in the front ones.
After the two recent surgeries, I'm not physically up to pullin' the hubs just yet.

KaptnKA S

[Bullitt390]

I agree those hand pump bleeders are retarded.

I hope my speed-bleeders don't sieze up. But they work great for me so far.

Josh

[BobbyFord]

Shouldn't need to bleed the entire system if just replacing the master.

[furnitureguy-123]

Just my 2c worth. I bought the bleeders with the check valve at Oreillys and they work just great!! I was able to bleed the whole system by myself. They are a bit pricy, (11.99) for two. Mine are not pot metal and fit just fine. Even came with dope on them to seal.
I was sceptical at first but I will buy them again.

[Bullitt390]

I am pretty sure when I bought mine years ago they were around 8 or 9 bucks. They are starting to get a little proud of those little suckers huh?

They do work slick though.

Josh

[m-mman]

Works great in a pinch and no fluid mess to worry about. Plus if you absolutely have to you can recycle the fluid.

All the above is true
However, the more pressure you put in to the system the greater the chance of clearing out ALL the air and giving a good firm pedal.
I have had some pesky bubbles that just would NOT come out without a foot on the pedal. (but I had enough of a pedal such that I could drive it over to someone for help)

As for recycling fluid . . . .
Putting dirt & crud back in the system aint the worst problem. The biggest problem is WATER!

Water lowers the boiling point of brake fluid. Clean, dry fluid boils at 400 degrees. Fluid/water boils at 280 degrees.
So if your brakes get over 280 degrees the fluid will "boil" and suddenly you will have no pedal because your system now has air and "needs to be bleed"

After the crash when your brakes cool down the 'air' is redisolved and a good firm pedal returns to be found by the crash invesigator who will disallow your story that your brakes failed. . . .

We have all done it, but BE CAREFUL!

Read more here: http://www.afcoracing.com/tech_pages/fluid.shtml

[fordman]

i got under my 4wd drive on sunday after i had put the master lines back on . i filled the master to make sure i had it full. got under thabck ready to bled the brakes with hte two person method. and when the brakes were pumped there was fluid squirting that i wouldnt have seen unless i was under the truck. it seems the place it was leaking from is the most favorite place for them to go bad at too. right before it goes into the bracket that leads to the rubber hose off of the rear end. it was spraing fluid onto the frame rail and was sitting on the rail not dripping onto the ground.

[Alvin in AZ]

IMO, Sam's post is a master piece. :)
After doing it "Sam's way" -by yourself even- you won't mess with any other way. :)

I have never ran into the problems M&M and others mentioned, YMMV?

Yeah, "recycle" your used brake fluid, use it for "hick paint remover". ;)

Alvin in AZ
ps- I'm fixing to tear into my 75's brakes today, either the front or the
rear systems are "leaking off" inside the master cylinder. :/