Clutch master cynlinder bench bleed, please help!

[2gspider]

Hi dsmtuners,

I wonder if someone can give a more clear instructions how to bench bleed the master cylinder before putting it in the place of old one. I found the info about taking out and replace the master cylinder, and also how to bleed after the unit installed; however, bleeding the new unit before installed info was kinda unclear.

Attachment is the picture of the unit i bought. i'm a newbie so please give me some detail info how to do it right. I want to do it right the first time. Also, my car is a 98 gs spyder

Thanks a lot, guys.

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i don't know why the picture didn't show up, if not here is the link

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[PieEyedPiper]

Maybe I did it wrong the last 2 times I swapped masters, but I didn't bleed shit before installation.

As I did it:
1. open up the slave and pump out as much fluid as I thought appropriate
2. disconnect and remove the master
3. install the new master and reconnect the lines
4. refill/bleed the clutch
5. bleed it every weekend for a couple of weeks (or as necessary ) by quickly loosening the slave as I push the fork in to release fluid/bubbles and cinch up the slave again before I've fully compressed the fork/rod into the cylinder (takes 3min with a 10mm wrench)

 

[90gsturboklipse]

Plan on pumping the hell out of it..... when I replaced mine, you didn't notice the clutch to be releasing until after a few hundred pumps.... yeah.... hundred. I thought it to be rediculous, but if at first you don't see results when you get it in the car, just bleed it out real good and then just sit in the car and keep on pumping. leave it sit for a while, and go back to pumping it. eventually, it will work.

 

[TALONTRAX]

I`ve always just gravity bled the system after installing the parts on the car:

Just install everything, & ensure that all the lines & fittings are tight, & fill the master cyl. reservoir & leave the cap off; then open the bleeder on the slave & let it drip for a few minutes (it may not drip immediately,this is the air in the system passing out). When it is dripping, be sure to not let the reservoir go empty. Do this for about 5 minutes, or maybe 3-4 refills of the cup, & it should be good to go . . .

 

[2gspider]

Thanks for the responds, you guys. How long ago did you replaced your clutch master cylinder?

 

[TALONTRAX]

My stuff is all original. I do peridocically change the fluid in the clutch & brake systems to keep contamination out, thus extending the service life of the parts . . .

 

[Defiant]

Bleeding's bleeding. You need to run the outlet into a container of brake fluid so it can't pull air back in, and you need to supply the reservoir so it doesn't run out of fluid.
It's not so crucial on a small master like ours as it is on some Detroit boat anchor with a cast-iron tank on top of the cylinder, but it still saves some bother. Trade-off is that you need to bother with a bit of fittings, hoses and tanks to bleed it.

 

[2gspider]

I tried to bench bleed the master cylinder, and boy, what a mess! Since i didn't have tube that big enough to cover the outlet. Anyway, i decided to put the new unit in, and damn brake fluid keep dripping out even when i tried to covered it.

Also, does it matter if i closed the lid of the reservoir after each refill during the process?

Ok, I bled Master cylinder at least 10 times, then push the rod of the left side of the Slave Cylinder then open to let fluid out. Now my pedal a bit firmer, however, when depress the clutch and when clutch pedal almost all the way at the floor, it make a squirt squeaky noise. Does it mean that there still air somewhere? or this is normal for the new master cylinder?

 

[TheBigPhantom]

Not to revive a dead thread but I also have this squeeking problem and my clutch engages and disnegages almost flat on the floor.

I didn't bench bleed the master so I'm hoping it's that.

Does gravity bleeding really work?

Also I bought a slave rod extender to see if that helps things out.

 

[Hollywood77]

Hey man, DON'T use a slave cylinder extension. That's not a good idea. It's only a band-aid for a mechanical fix that you can do yourself.

Instead of us using an extension (BAD IDEA), we adjust the pedal engagement point via the locknut on the adjusting rod (on the master cyl.).

If we can't get consistent clutch-pedal travel, we look at replacing either the slave or the master cylinders. We don't want any extensions.

While your slave is still bolted to the front of your tranny, pull back the rubber boot, and see if you see any fluid in there. It should be DRY. If you have fluid under that boot, replace the slave, re-bleed the system, and if necessary, adjust your clutch pedal.

NO EXTENSIONS!!