For bench bleeding you just have to plug the two ports on the master cyl with the plugs provided with the new M/C. Then fill the reservoir with new clean brake fliud. You then use a hammer handle, or broom handle to push the piston in.
Push the piston in slowly, and repetedly until it becomes hard, and you are done, and ready to install on the car. Leave the plugs in until you are ready to hook up the lines.

 

Are you folks saying that if I take a new MC plug up the 2 ports I should be able to press in the plunger or if it was in the car and level I can press on the brakes and the pedal should move??

 

The MC bench bleeding kit:

 

Yes. You will be able to press in the plunger a few times as the air is bled out when bench bleeding it. Once all the air is bled out. You might only get the plunger to move very slightly if at all.

I have done this on the vehicle also (without it running), but the mechanical advantage afforded by the pedal linkage is greater, and you can get the plunger to move slightly more than when bleeding it on a bench, but the outcome is the same. The pedal will get very hard, and it won't move very far if at all.

The method of plugging the ports is the best that I have found, and it will always work. Once you can't move the plunger any more you are done, and have all the air out of the M/C.

 

Perfect.. One last question. If the pedal never gets really hard or still moves quit a bit, would it be fair to say the MC has an internal leak?

 

Yes that is most likely the problem. Feel under the power brake booster. If it is wet the MC has a external leak.
A new MC is about $30.00 at Oreilly's

 

I have a master cylinder bleeding kit......however, since I made my pressure bleeder I haven't had to use it....and I've replaced my Master Cylinder.
My brakes have been better than ever since I started using the pressure bleeder. I highly recommend it.

 

Just replaced the MC with the new alm Willwood and still having issues. My goal was to make sure it was not a bad MC, now I am changing the Prop valve becasue there is nothing left to check.

 

You have to bench bleed it outside of the car, and the plug methode is a long shot at best, probably just a way for the rebuilder to save money on a kit. use the tried and true methode, recirculate the fluid with the $6 kit, untill no air bubbles show up. did you recently change your disks? any leaks from your calipers? these things will pump air with runout, well known. what kind of calipers are you useing?

 

Bleeding brakes is a pain in the a---------.

 

No change in the Disks or calip all prety new less then 500 miles on them. No leaks from anywhere and stock gm calp.

What I have done so far:
New Willwood MC
New hard lines and rubber lines in the front and rear
Bench bleed MC at least 3 times and another 2 on the car
Bleed all brakes gravity first then used the motive all the way around in the correct order

Pedal hard as a rock and does not budge with engine off. turn engine on pedal goes soft with very little brake...it will stop, but it takes a while.

Hey MM I agree brakes suck!!! my car has been in the air for 1 month now due to brakes and the track season is just about over

 

sounds like air. Yea, put it up on all 4 with jack stands. this is what I did, since you have a motive, get two jars and bleed both the rears at the same time, then, as your bleeding both, take your fingers and pull in on the pads, towards the calipers. I did this and got a big air bubble from both sides on the rears. seems like air hides on the irregular shape of the pistons even though your bleeding it for a while. then close the bleeders, step on the brakes to reseat the pads and then re-open the bleeders and pull on them again, this time you should see little or nothing. Do this 3 times, then tap on the calipers with a piece of wood for a while. then do the front the same way. Also when you raise the car, check for endplay in the rear bearings by trying to move the rear tire at 3 and 9, and 12 and 6, crosswise. you may have developed end play which is putting air into the rear of your braking system. gonna needs lots of fluid, 3 liters I would say 'cause your gonna do allot of bleeding. this will bleed your brakes perfectly. they should work great. Check the endpaly as that will kill them after a short drive with the original lip seal calipers.

 

I will give that a shot thanks.... I also just ordered a new prop valve so I will wait till that comes in next week. I only want to undergo this bleeding crap one more time or my brain will start bleeding.

Using the motive at 15 lbs should the fluid come squirting out, freely or dribble?

 

I understand, beleive me, the proceedure and 2 new O-ring calipers finaly solved my brake problems,, I'll tell you, you've got to be able to trust your brakes. I waqs surprised at the amount of air that released when I moved the pads. Brakes can be a "B". just see the 2 Gallons of brake fluid I've got in my hallway. leanrn allot though.... the rears on mine at 15 lbs were a continous flow, but about half the fronts at the same pressure. Extreemly slow, can barly see the fluid raisning in the jar, impreceptable.

 

If you are having problems with air in the system, and you can't locate the source there is a trick to finding it. (if you have no leaks)

Buy a set of 4 hose pinch-off pliers. (these will not damage the rubber hoses) attach the pliers to the 4 hoses on the Corvette. Depress the brake pedal. If the pedal is hard you have air trapped at one of the wheels. If the pedal is soft the master cyl has air in it or it is faulty.

To determine which wheel is bad (hard pedal with pliers installed) remove the pliers from the hose furthest from the master, and press the brake pedal. If you get a soft pedal you have located the caliper with the trapped air.
If you get a hard pedal move to the next wheel closest to the master cyl, and press the brake pedal again. Repeat the process untill you find the offending caliper.

 

Hi Darin, I'm having the same problem. It presented itself in the form of a locked down caliper on the highway and I decided to pull the whole system and reinstall everything new with a kit from VB&P.

I haven't even gotten to the water pump/fan combo you sent me several weeks ago and now it's snowing in Chicago. Guess I've got all winter now...

You got some pics of your new set up with the electric fans, etc? Send them over I'd like to take a look.

Good luck.

Dan

 

WOW very nice idea!! thanks dude, but what the heck is a 4 hose pinch-off pliers?

 

Hey Dan,

Everything takes time and winter is a great time to work on the cars not much else to do.

I will send a pic later today the wife has the camera. I love my new set up with the elec fans and water pump, it really cleaned things up in the engine compartment.

It looks as if Dr. J helped me find a new way to look for air in the system.

 

I believe the reference is to 4 pairs of "hose pinch off pliers". You need one for each line just before the caliper.

I have used this method before. It is very effective when trying to isolate a problem. However, this only works with rubber lines, mine are stainless and you can't pinch them off...


Here's link to sears, maybe not the most cost effective but it has a pic of what you need:

http://www.sears.com/shc/s/p_10153_1...0070921x00003a

 

Perfect...thanks man!

Not the best pics, but you can get an idea. You may have to click on them a few times to come up and I do not know why.

http://www.angelfire.com/crazy/76sti...ngine-bay?i=26

http://www.angelfire.com/crazy/76sti...ngine-bay?i=24

http://www.angelfire.com/crazy/76sti...ngine-bay?i=25

http://www.angelfire.com/crazy/76sti...pic-2?i=27&s=1