Bench Bleeding

[theconductor]

I am preparing to install the cobra brake upgrade on my fox in a couple of weeks. It recommends bench bleeding. How necessary is that? What is the best/easiest way to do it?

Thanks for any help..

-kyle

 

[5.0ina66]

I am preparing to install the cobra brake upgrade on my fox in a couple of weeks. It recommends bench bleeding. How necessary is that? What is the best/easiest way to do it?

Thanks for any help..

-kyle

It's mandatory. You HAVE to bench bleed the master cyl. Otherwise you'll have air trapped in the MC that will NEVER, and I mean NEVER come out no matter how much you bleed the brakes. Easiest way I've ever seen to do it right is probably to plug the MC ports, fill it, and pump the pedal until there are no more bubbles. Another easy way is to buy a MC bench bleeding kit at the parts store for like $3, it works very similarly to that method.

I wish I'd done that on my Fury, the MC is still full of air and I only get brakes after the 5th pump.
HTH
-- Kyle

 

[MYSC351]

Double post

 

[MYSC351]

It's mandatory. ... .... Another easy way is to buy a MC bench bleeding kit at the parts store for like $3, it works very similarly to that method.
-- Kyle

I agree 100%...It's mandatory unless you want to spend hours bleeding the brake system..

The kit actually works REALLY well. The kits are VERY cheap, they even come with every new master cylinder I've seen... The kit is basically two clear hoses and two plastic fittings....You install the master cylinder then screw the plastic fittings into where your brake lines go and run the clear hoses from the fitting into the fill hole of the cylinder....Then you pump the brakes until only fluid is leaving the master cylinder....This way all the fluid coming out of your brake line is rerouted right back into your master cylinder..The cost of just the extra brake fluid you will need if you don't bench bleed will cost more than that kit.

BTW: 5.0ina66,
Have you tried a professional brake fluid flush? We have a machine at our work that pressurizes the system. All you have to do is hook the machine up to the master cylinder, then crack the bleeders one at a time...Works really well at getting those pesky air bubbles out...

 

[93 LX]

make sure the mc is level. You have to jack up the back of the car allot to make it level.

 

[90_Red_LX]

We put our master cylinders in a table vise plugged up and work the air out by hand before installing.

 

[Red9250]

Here is what I did without a vise:

Got to NAPA and get their universal bench bleed kit. Take the MC out of the car. Hook the kit up by hooking up the plastic fittings and tubes and then placing the tubes back into the fluid reservoir. Put the MC on the floor in front of a step or something with the part that would face the front of the car butted up against the step. Make sure it's level. Get a wooden spoon or something similar to push the piston in. Fill the reservoir. Push the MC in with the end of the wooden spoon a bunch of times. Each time you need to "pinch" the tubes to keep them from pulling the air you pushed out back in. Add brake fluid if the reservoir starts getting low. When you are done, clamp the tubes but leave them hooked up. Move the MC to the car. Bolt it up to the booster. Put a rag or something underneath the MC to catch dripping fluid. Remove the plastic fittings and put the brake lines in as quickly as possible.

It helps to do it off the car because you can tilt/shake the MC to move the air around to make sure you get it all out.

I did this and it worked perfectly.

 

[sickazzstang]

 

[Red9250]

Have all 34 of your posts been that informative?

 

[theconductor]

Have all 34 of your posts been that informative?

Yeah, no kidding!

Thanks for the advice red92,


Kyle

 

[1991vert]

what i've done for bench bleeding is fill the resevoir, put the fittings/hoses on and loop the hoses back around into the fluid. no pinching is needed

 

[90lxcoupe]

i never did that and my brakes are just fine... mabye i got lucky for once

 

[theconductor]

What about the new calipers? Do they need bench bleeding also?

 

[Mavrick]

Only your master cylinder needs to be bench bled. Calipers only require normal bleeding to get the air out.

Bench bleeding is as easy as pumping the MC with your fingers over the ports, letting the fluid/air out and sealing the ports with your fingers when the MC piston is drawn back to its "stock" position.

I have found some of the plastic kits that come with new master cylinders are junk and just leak. For the mustang years ago i bought a couple new fittings to fit my master cylinder, and looped metal line back into the reservoir.

Definetly bench bleed your MC, but don't get too worked up over it - it's simple and easy.

 

[theconductor]

cool, thanks for the calming words!