Bench Bleeding m/c..

[5.7 hemi]

The ten pound residual valve make the pedal worse, it was as though I had no pedal at all. Gonna take it off and try something else, what, I dont know, but something has to be done to fix it.

 

[mrkinger]

I had the same problem with no pedal,i had two peices of brake line,screwed them onto the m/c ,then i attached two clear plastic lines to them.Held the plastic line below the fluid level and had my buddy pump the crap out of the brake pedal .problem solved .You will be able to see the air in the clear lines

 

[5.7 hemi]

I dont think it's air in the mc, cause it's been bled more than enough times, but who knows, maybe one last time might do the trick.

 

[Joe Mopar]

I dont think it's air in the mc, cause it's been bled more than enough times, but who knows, maybe one last time might do the trick.

Hey Zack doing what Mrkinger has suggested I connected a couple lines going back into m/c and bled it again for a longer period than I had before and let me tell you it has made a big difference. I have pedal now without it going all the way to floor. I just might try it again myself and then do each wheel again.

Joe

 

[mrkinger]

Perfect ,thats what i did ,forgot to tell you about redoing each wheel after.my pedal went to the floor untill i did that.Dont know were the air came from ,but there was lots.just have to be patient ,if you run the m/c dry ,you have to start all over again
Paul

 

[5.7 hemi]

Gonna do it this afternoon when my buddy gets here. Hopefully we'll get right this time.

 

[5.7 hemi]

After all the bleeding, my dad stopped by and found out that I'm OVERBOOSTED. So instead of changing out the booster for a smaller one, I'm gonna make a restrictor to plug the vacum. A 3/8 piece of aluminum, drilled with a 1/8 inch hole. This should work just fine, if not drill the hole a size bigger till I have the pedal I want.

 

[Revhendo]

How Does a Brake Booster Work?

.Location
The brake booster is situated between the brake pedal and the master cylinder. The body, booster piston, piston return spring, control valve mechanism, and the reaction mechanism, are the parts that make up the unit known as a brake booster. There are two chambers in the booster body: the constant and variable pressure chambers. Bridging the two chambers is a mechanism called a diaphragm. A control valve device manages the pressure within the variable pressure chamber.

Increased force
A brake booster increases the force applied by the brake pedal. The amount of increased force is dependent on the diaphragm. The pedal force is doubled (or quadrupled) by the use of atmospheric pressure and the manifold vacuum of the car engine. The piston is moved by a spring that is under pressure when the vacuum is working on both sides of the piston. What makes the brake booster work is this pressure difference acting on the components within the brake booster body.

Air valve off/ on
The air valve is mated to the valve operating rod. A return spring tugs the air valve to the right (the OFF position). In opposition, the control valve is moved over to the left by the control valve spring. The air valve contracts the control valve. As a result, the outside air passing into the air cleaner mechanism does not reach the variable pressure chamber. A passage between the constant pressure chamber and the variable pressure chamber is created. The passage allows the vacuum path into the variable pressure chamber, moving the piston to the right side of the chamber. The air valve moves away from the control valve, bringing outside pressure into the variable pressure chamber. The differential between the constant and variable pressure chambers moves the piston left. The reaction disc knocks the booster rod left, which produces braking force.
The air valve is in the ON position when the brake pedal is depressed. The valve operating rod presses the air valve to the left side. The control valve makes contact with the vacuum valve, which blocks the passage between the constant pressure chamber and the variable pressure chamber.

Operation in action
In action, when the pressure is put on the pedal, the same pressure is transferred to the booster air valve. The master cylinder applies the brakes in response to pressure from the brake booster. In essence, atmospheric air enters the piston chamber, causing the piston to push against the spring (compressing the spring). The piston moves left, and the pressure moves the piston rod. This pressure then causes the piston rod to move against the master cylinder's piston. When the piston in the master cylinder moves, the result is the production of hydraulic power being applied by the brake booster to the vehicle's braking system.


Read more: How Does a Brake Booster Work? | eHow.com http://www.ehow.com/how-does_5015014_brake-booster-work.html#ixzz1MUlqcQ83

 

[Joe Mopar]

After all the bleeding, my dad stopped by and found out that I'm OVERBOOSTED. So instead of changing out the booster for a smaller one, I'm gonna make a restrictor to plug the vacum. A 3/8 piece of aluminum, drilled with a 1/8 inch hole. This should work just fine, if not drill the hole a size bigger till I have the pedal I want.

Zack let me know how that works out for you.

 

[SUPERSTOCKRACER]

Sometimes a master cyl likes to hold a lot of air and the best way to get rid if it is to cycle the piston - as in bench bleeding. I'm with Rev. Just loop the plastic tubes back into the reservoir and stroke it a few times then bleed the system. Job done.

yep, its the easiest best way. :cya:

 

[Revhendo]

Reaction disc.

 

[5.7 hemi]

Rev, I totally forgot to check the reaction disc, I will this Sat coming up.

 

[bluefury]

Is it really necessary to do so?​

I would not ever try to install a master cyl without first bench bleeding it. I've been doing this for too long to waste time, (and fluid) trying to bleed it through the system. Do yourself a favor.... bench bleed.​

 

[5.7 hemi]

The master has been bled at least 3 times if not more.

 

[Revhendo]

The master has been bled at least 3 times if not more.

Pretty sure you've passed the bleeding phase a long time ago. I would bet you're into full on transfusions now......:upside down:

 

[5.7 hemi]

Aint that the truth!!!!