Brake bleeding help needed!
 

Trying to bleed the system for the first time with new SS lines. I have read alot of posts about the right way to do it. Heres the problem, The brass plunger on the front of the combination/proportioning valve will not go in. The manual says to depress it, but it wont. I even bought a new one thinking my old one was bad since it didn't go in either. I bench bled the master, and started bleeding at the drivers rear (actually further from the Master than the passengers side if you look at how long the brake lines are)

Anyone know if it needs to go in, or should I just make sure it doesn't come further out with a clamp. Been getting air from the rear lines all day and have gone through 1/2 gallon of dot3. Almost to the point of taking it to a shop... but I like to do as much as I can myself.

CST350

Re: Brake bleeding help needed!
 

I assume youve done this before successfully right?

Re: Brake bleeding help needed!
 

maybe this will help ,

First start with the normal gravity bleed . Next instead of pumping the brakes several times and then bleeding it, have the person in the cab push the pedal down 1 time and hold it , you then open the bleeder until the pressure is gone ( usally about 1 or 2 seconds ) close the bleeder then tell the person in the cab to release the pedal , wait about 5 seconds then have the person in the cab press the brake 1 time again ,hold it , and then you bleed it . Repeat this process until you start getting good fluid and move to the next wheel.

This pushes the fluid instead of cavatating the fluid and making more little air bubbles. Start and the right rear , left rear , right front , left front then master cyl just to double check it .

The plunger on the proportioning valve will push out when you apply the brake after all of the fluid is bleed and no more air is in the system .

Tim

Re: Brake bleeding help needed!
 

Thanks Tim, I will give that method a go...

was using a vacum pump and speed bleeders. I have bled the brakes when I went to discs, but it was with stock bleeders.

Re: Brake bleeding help needed!
 

when bleeding rears you should start at left rear as that is the furthest away from the master cylinder then the right rear
lots of guys make the mistake of doing it backwards and end up still with air problems

Re: Brake bleeding help needed!
 

left = drivers side???

Re: Brake bleeding help needed!
 

left right it dont matter which side if you bleed the brakes my way you dont need anyone to pump the brakes but your self one man job ,you can do all 4 brakes at once too ,just make sure the master cylinder is full and dont let it go dry , you will need 4 snapple bottles empty ,4 rubber hoses long enuff to reach the bleeder to bottle 2 feet should do on each brake ,fill the bottles with new brake fluid 1/4 way up,and loosen the bleeder open ,put the hose on the end to the bleeder ,do this to all 4 brakes ,now pump the brake pedal until the air bubble stop blowing and brake fluid is filling up in the bottles ,make sure master cyl. is full so check very 5 pumps or so ,take your time gravity feed will take over when not pumping ,once you get fluid coming out and no bubbles ,close the bleeders and remove hose and bottle ,pedal should be nice a firm ,clean operation ,good way to flush system too

Re: Brake bleeding help needed!
 

really that works...i figured everytime u let go of the brake it would suck in any air trapped i th ehose.. cool ill hAve
TO TRY

Re: Brake bleeding help needed!
 

really that works...i figured everytime u let go of the brake it would suck in any air trapped i th ehose.. cool ill hAve
TO TRY

Re: Brake bleeding help needed!
 

it will suck back in but not enuff to let air in the system once u get steady stream of fluid then close the bleeder

Re: Brake bleeding help needed!
 

that is correct// you have a brake line that run down the passenger side goes into a rubber hose then a junction on the rear axel an 18' tube goes to the passenger side brake a 36" tube goes to the drivers side brake

that should seem to tell you that the drivers side brake cylinder is further away from the master cylinder than the short tube to the passenger side brake cylinder

Re: Brake bleeding help needed!
 

I got to try that snapple method.

Re: Brake bleeding help needed!
 

I'm amazed at how many people say it matters which side to do first.
You have one line that goes the length of the vehicle, that goes to a T fitting, then left and right.
Same thing to the front.
I have led the brakes on hundreds of cars and trucks (mostly trucks) and close to 50% of them have been from a dry master cylinder. It doesn't matter what side you start from, and unless it is a 66 or lder with a single pot master cylinder, it doesn't matter what end of the vehicle you start from.

Re: Brake bleeding help needed!
 

I will definitely try that method. However, I still need to check the lines for air bubbles while someone else is pumping the pedal, making this a two man job, correct?

Thanks for the tip.

M

Re: Brake bleeding help needed!
 

Bleeding brakes is my least favorite thing to do. Im going to have to see if I can find some snapple, I cant get it around here I dont believe.

Re: Brake bleeding help needed!
 

I had to replace the MC on my '67 (power discs) a couple of months back. I've been using a vacuum pump to bleed brakes for many years. This time I just could not get the rears. I had my son stop by to do the manual method as was described above. After several cycles and my son making sure the reservoir never went dry, I had to get up and check for myself. I know, I should be more trusting.

There was fluid all around the MC, dripping on the frame and my son said he had not spilled any of it.

I had tightened the flare nuts on the MC well enough, or so I thought. I had to give it an extra grunt to stop the leak.
The vacuum pump had been sucking air into the line at the loose fitting.
You said you replaced all the lines so that is where I would be looking. Pumping the fluid through from the MC may sprout some leaks as mine did.

Fastwillie, he says he has speed bleeders on there. Will gravity feed work with those spring loaded, one way valves or will he have to replace them with the original? I've never used those bleeders.

Re: Brake bleeding help needed!
 

its easier if someone help ya,they can close the bleeder once the air is gone, but i been doing this so long i can do myself
i just make sure the mastercy is full ,once the bottle gets full i know theres no air all fluid

Re: Brake bleeding help needed!
 

I like doing things myself rather than relying on help so I made a pressurized bleeder system. (just a piece of steel with an air fitting) :lol:

Cut a piece of thick plate steel (3/16 or so, I used 1/4 inch myself) that fits on top of the master cylinder to cover both openings. Glue a piece of rubber on the bottom to act as a seal. Install an air fitting above one of the openings (I sealed mine around the threads with JB weld) Then put a small notch in the bottom of the plate so air can go to both chambers of the master cylinder. All that's left is to set it on top of the master cylinder and use 2 C clamps to hold it tightly down.

Hook up your air compressor and apply about 20-25lbs of pressure, go under and bleed at each wheel. This takes out the "middle man" in bleeding brakes.


It sounds like alot of work but once this tool is made, it lasts a lifetime! :chevy:

Here's some pics of it in action on my 72 Chevelle:

Re: Brake bleeding help needed!
 

great sounding way to do this. very interested and going to try it out.

Re: Brake bleeding help needed!
 

lots of awesome ideas I'm going to have to save this thread :)
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Re: Brake bleeding help needed!
 

You all are rocket scientists on here!!! I love it. I have been fooling with my brakes for a week now, looking for an air/fluid leak. I can’t wait to get home tomorrow and finally get my brakes

Re: Brake bleeding help needed!
 

You don't push the prop valve pin in, just clamp it to keep from pushing out. I bled my Blazer TOO many times before doing this and was getting air from the rears every time ( very little fluid as well).

Re: Brake bleeding help needed!
 

That is AWESOME! They have kit out that are made to do this, but they are expensive. My brakes are fine now, but Im going to make one of these the next time I have to bleed mine. :metal: