9T3VETTE

Hey guys, i Just finished the c5 brake upgrade on my 93. I replaced all the lines with SS and also put in the DRM bias spring.

I have some questions regarding the filling of the hydraulic system and bleeding the air. The whole is dry due to the new bias spring. The master went dry and the flex lines as well.

In the FSM it states that the prime pipe must be bled in the rear storage compartment at the ABS modulator unit. This is not a big deal, however i'm confused by the next part in the FSM. How is the master cylinder bleeding done? Is it completely necessary in my case?

It seems like the brake hose needs to be removed at the master to purge air but i'm not 100% sure. Can someone help?

Sorry I dont have the FSM handy so I cant post the exact procedure. I can do so later.

PLRX

Did you fill up and bled the master cylinder before you re-install it back on the booster?

9T3VETTE

The master wasn't taking out of the car or booster...The system drained through the lines on the caliper side. I replaced the bias spring with the master still on the car.

mako41

You need to bleed the master before you start to bleed the entire system. You can do this while its still mounted to the booster. This proceedure will remove any air trapped in the M/C bore that can't be bleed out thru the 4 calipers.

94z07fx3

BTW Bleeding the master when it is installed is easier if you can raise the rear (of the car) a bit to level the bore.

wschmidt

[QUOTE=dubin4life;1580818362]
It seems like the brake hose needs to be removed at the master to purge air but i'm not 100% sure. Can someone help?

QUOTE]

I dont have my FSM or vette handy either, but yes you need to bleed the M/C. IIRC, this is supposed to be done outside the vehicle. I have not done this on a vette, but when I did this on my truck after doing all new brakes and lines, I would loosen the nut on the line into the cylinder, have someone push the pedal in, tighten the nut, let the pedal out, and repeat. Very similar to the two man method for bleeding at the calipers, the only bad thing is that unlike with calipers you cant really put a clear tube on the nipple to see for sure that there are no air bubbles, I just put a rag down and repeated many times to be sure. Been driving the truck for over a year now with no issue.

desertmike1

Did my brake bleed, after caliper(s) rebuild, with a Mighty Vac...no problems.

jaa1992

Get a master bleed kit, basically two plastic parts that screw into the front and rear ports on the master, then short tubes to loop back into the master.
Level by raisng the car, fill the resevoir up with fluid, pump the brake pedal - a lot.
put something under the plastic parts to collect the brake fluid and one at a time quickly take them off and put yout hard lines back on.

Bleed normally from there.

9T3VETTE

Thanks for the help, looks like I'll need to get a master cylinder bleed kit. So the question is, will it be as easy on the car or should I just remove it? Sounds like it may be hard not to spill fluid all over of I bleed it on the car...

94z07fx3

it would be easier with a helper but solo just make sure the lines from the bleed kit are well inside the MC's res clip them in if you can rig it. Be aware that it is possible with the booster to push so fast that you shoot the little plastic fittings out of the holes so easy does it.

leesvet

Its a matter of protecting the paint more than anything else...brake fluid etches paint on contact due to the high acid content of the fluid. A good reason to have a coat of wax on the car...
Brake fluid is hard on some rubber as well. Line the work area with plastic bags and have soapy water and rags handy for immediate wipe up if something gets splattered...

Taking the unit off and doing a "bench-bleed" means transporting it back and forth with fluid in it...just another means of dripping on something. Harder to hold and operate off the car too.

I found some self bleeding caliper screws that make the lower end a bit easier...stick the clear hose on the screw and into a coke bottle, crack the screw open and pump the pedal or turn on the bleeder pump (apply pressure) and the bleed screws have a built in check valve that lets fluid out, but no air back in. Tighten bleed screw when done.
Comes in handy.

9T3VETTE

Ok, thanks guys i'll bleed it with the master on the car. Wont get to it until next weekend, but im glad i know what needs to be done now.