Bleeding master cyl.

V8Mikie · Post by **V8Mikie** » Sat Sep 17, 2005 8:39 pm

I replaced the brake lines/calipers this weekend and bled all four. However, I have a lot of pedal travel and I suspect the problem lies within the MC. It's not bad I just think it has air in it. Can someone give me instructions in laymens terms on how to bleed it? The Chiltons is a little vague IMO.

Weponhead · Post by **Weponhead** » Sun Sep 18, 2005 12:35 pm

ok, get yourself a little bleeder buddy from the parts store, should be like a 3/16'ths hose with a bottle on the end. hook that to the nipple on your caliper this always works best with two people unless your creative. but first you want to start with the caliper FARTHEST from the master cylinder so the passenger side rear. To bleed, fully depress the brake pedal and hold then open the bleeder valve on the caliper, close the bleeder valve once fluid has stopped moving and then and ONLY then release the brake pedal. Also when your bleeding , keep the top on the master cylinder but keep an eye on fluid level. if you leave the top off you may well make a fountain that sprays fluid all over the front compartment of the car. repeat the depress, open , close, release process until there is no more air in the lines. and move in the order of "pass rear , drivers rear , pass front , drivers front."

Shaun41178(2) · Post by **Shaun41178(2)** » Sun Sep 18, 2005 12:39 pm

word. Thats about as simple as you can describe it.

whipped · Post by **whipped** » Sun Sep 18, 2005 6:06 pm

I think I have the same problem, but I've bleed the hell out of my system. It just feels like I have 75% braking capacity. I've bled it regularly, gravity style, power bled, bled at the master cylinder connections... It's probably a bad MC, but I don't feel like replacing it at the moment.

p8ntman442 · Post by **p8ntman442** » Sun Sep 18, 2005 6:56 pm

a bad master can fail and you will have no brakes. fix the problem now.

V8Mikie · Post by **V8Mikie** » Sun Sep 18, 2005 7:09 pm

Weponhead wrote:ok, get yourself a little bleeder buddy from the parts store, should be like a 3/16'ths hose with a bottle on the end. hook that to the nipple on your caliper this always works best with two people unless your creative. but first you want to start with the caliper FARTHEST from the master cylinder so the passenger side rear. To bleed, fully depress the brake pedal and hold then open the bleeder valve on the caliper, close the bleeder valve once fluid has stopped moving and then and ONLY then release the brake pedal. Also when your bleeding , keep the top on the master cylinder but keep an eye on fluid level. if you leave the top off you may well make a fountain that sprays fluid all over the front compartment of the car. repeat the depress, open , close, release process until there is no more air in the lines. and move in the order of "pass rear , drivers rear , pass front , drivers front."

No I need to know how to bleed the Master Cyl.

I already bled my brakes but there is air somewhere in the system.

Fast88Fiero · Post by **Fast88Fiero** » Sun Sep 18, 2005 9:04 pm

Get a master cylinder bleeding kit. It comes with hoses and adaptors that fit in place of your brake lines in the master cylinder. You screw the plastic adaptors into the master cylinder in place of the brake lines. Connect the hoses that come in the kit to the plastic adaptors and put the other end in the brake fluid in the master cylinder. Pump your brake pedal slowly. Get someone to help you so you can watch and see if any air comes out. After youre finished reconnect your brake lines to the master cylinder and bleed your brakes normally. The master cylinder bleeding kit will most likely come with instructions. Every master cylinder I have ever installed at work has come with bleeding instructions.

V8Mikie · Post by **V8Mikie** » Mon Sep 19, 2005 9:22 am

Fast88Fiero wrote:Get a master cylinder bleeding kit. It comes with hoses and adaptors that fit in place of your brake lines in the master cylinder. You screw the plastic adaptors into the master cylinder in place of the brake lines. Connect the hoses that come in the kit to the plastic adaptors and put the other end in the brake fluid in the master cylinder. Pump your brake pedal slowly. Get someone to help you so you can watch and see if any air comes out. After youre finished reconnect your brake lines to the master cylinder and bleed your brakes normally. The master cylinder bleeding kit will most likely come with instructions. Every master cylinder I have ever installed at work has come with bleeding instructions.

Cool, thanks. Any idea where they sell them? I checked AutoZone and they didnt have them, but there is a Harbor Freight around here.

Kohburn · Post by **Kohburn** » Mon Sep 19, 2005 9:36 am

I need to do the same thing - after my big brake upgrade i slapped a dry blazer master on there and bled the system till air stopped coming out - but the brake peddle doesn't firm up till i'm 60% down - then it stops the car well.. got to be air trapped in the master

V8Mikie · Post by **V8Mikie** » Mon Sep 19, 2005 4:01 pm

Kohburn wrote:I need to do the same thing - after my big brake upgrade i slapped a dry blazer master on there and bled the system till air stopped coming out - but the brake peddle doesn't firm up till i'm 60% down - then it stops the car well.. got to be air trapped in the master

Yup, sounds like mine. I talked to about 5 people and they all said its air in the master cyl.

fIEROWISEGUY · Post by **fIEROWISEGUY** » Thu Sep 22, 2005 9:43 pm

Every manual, and most rebuilders call for "Bench Bleeding" the master cylinder before putting it in the car.

Pushing the brake pedal cannot completely stroke the pistons in the master cylinder to push out all the air in the cylinder. They tell you to first put the master cylinder in a bench vise, and connect the previously mentioned tubes from the ports, back into the master cylinder reservoir.

Now, you can completely push the pushrod all the way into the cylinder space, pushing out that last little bit of air. Repeat several times, until no air comes out the little tubes.

richfiero · Post by **richfiero** » Tue Sep 27, 2005 6:07 pm

step 1 fill the master cylinder to the recommended full level.
step 2 have an assistant slowly depress the brake pedal as you "crack open" the master. (DO NOT PUSH PEDAL TO THE FLOOR, IF THE MASTER DOES ITS FUL TRAVEL IT COULD GET CUAGHT IN SOM GUNK AND TEAR THE PRIMARY SEAL.) at the the line closest to the brake booster then do the other line.
step 3 reapeat process several times until the brake pedal feels solid.

If you depressed the brake pedal to the floor. you may have torn the primary seal if its an older master.

Snowcrash · Post by **Snowcrash** » Fri Jul 21, 2006 3:32 pm

Adjust the emergency brake cable.

Starlite528 · Post by **Starlite528** » Wed Jul 26, 2006 2:35 pm

Snowcrash wrote:Adjust the emergency brake cable.

Seconded. My father replaced the master cylinder on the Fiero when he owned it, and he couldn't get the brakes to work properly until one day he used the parking brake and it nearly solved the problem.

No Gurantees though.

Mach10 · Post by **Mach10** » Wed Jul 26, 2006 2:56 pm

Holy undead thread, batman!

Real Fiero Tech

Bleeding master cyl.

Bleeding master cyl.

I BLEED for my brakes!