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Hydraulic clutch bleeder screw

3K views 13 replies 5 participants last post by  henny496 
#1 ·
Hello
I have a hyd clutch master and slave from a mid to late 80's Camaro
It is new and this is in a custom application. The slave is higher than the master(floor mounted pedals)
There is a brass set screw (bleeder screw)on the slave cylinder that has an allen key head
I am by myself doing this, tried all day yesterday to bleed it, had it close once but then lost it later trying to get the last of the air out
I have a vacuum pump, but I would need some type of conventional bleeder screw to go in place of the set screw.
Does anyone know what bleeder screw will work , so I can do this myself with a vacuum pump. The threads are course...looks like 5/16 -18 but I wonder about metric......just don't know and frustrated
I need an extra arm and a leg to do this the conventional way,,...and the dogs won't help
thanks
Tom
 
#2 ·
henny496 said:
Hello
I have a hyd clutch master and slave from a mid to late 80's Camaro
It is new and this is in a custom application. The slave is higher than the master(floor mounted pedals)
There is a brass set screw (bleeder screw)on the slave cylinder that has an allen key head
I am by myself doing this, tried all day yesterday to bleed it, had it close once but then lost it later trying to get the last of the air out
I have a vacuum pump, but I would need some type of conventional bleeder screw to go in place of the set screw.
Does anyone know what bleeder screw will work , so I can do this myself with a vacuum pump. The threads are course...looks like 5/16 -18 but I wonder about metric......just don't know and frustrated
I need an extra arm and a leg to do this the conventional way,,...and the dogs won't help
thanks
Tom
All that need be done, is to crack the allen at the slave, press the pedal until fluid flows, lock the allen. Repeat. The air will always go UP, towards the slave.

Obviously, if the allen is at the bottom of how the slave is mounted, it will need to be either pressure bled or turned so the allen is at the top.
 
#4 ·
henny496 said:
Thanks for that info. The problem is trying to get someone to help
I will see what I can do
Tom
Help? What's that??

You are talking to a guy who rebuilt a TH400 tranny- with the tranny still in the car! I can't count all the AT's I've changed by myself. It's all in how you hold your mouth.

Take a bungee cord. Wrap/strap that mother around the pedal and whatever's close enough that it can be used to hold the pedal down.

Now, at your leisure, go back up to where the slave is at, crack the bleeder, and let the air out.

Repeat, pumping the pedal gently between bleeds.
 
#5 ·
Is it the master that sticks out 90* from the firewall
or the one that sits at about 45*

there could be air trapped in the masters or a line that refuses to come out.

I have a master from an 88 Chevy pick-up and the slave from an 86/7.

90* master----The only way I can get it to bleed, is to jack up the rear of the car. Seems a bubble gets hung up in or near the master and needs to purge thru the resevoir
 
#6 ·
Thanks Cobalt and Brian 59 for your replies
I will go back out , take off the slave and rebleed the line and master. I will then push the rod in and out of the slave with a hose from the line fitting a can of brake fluid, then put it back on
I will still have some air, but I can pump the pedal and then cut a 2x4 to jam between the cage and the pedal to hold it down. I am just afriad of the pedal releasing once it gets pressure causing the board to fall.then air in the system, but maybe a bungee cord back up somewhere may help
(Brian59 ) The master has the mounting flange on a 45 * angle and the slave bolts on at a 90* angle. The car is already up on stands , so I cannot move it(other parts I am waiting on)
thanks again
Tom
 
#7 · (Edited)
I went to the local auto parts store and got a 10 mm bleed screw for brakes. I measured against the set screw and all I had to do was carefully grind the point off the bleed screw, so it has a flat bottom, the same as the set screw
Now I can vacuum bleed it
this hyd clutch has been a pain in the butt..I hope it has been worth the effort


it did not work....I give up for today
 
#9 ·
Thanks for your reply T-bucket
I had gone back out, took the slave off again and submersed it into a container full of brake fluid, then pushed the rod back and forth until all the air was out of it(left the slave in the container of brake fluid)
I then put the high pressure line from the master into the container and pushed the clutch in an out many times until I was sure not more air was coming out
I then connected the line and slave, while both were still submersed in the brake fluid
.......very messy, but I think I got it
I have to bleed the brakes tomorrow, so may be using the wood idea if the vacuum pump gives me a headache, and at this point I am expecting more headaches lol
thanks again
Tom
 
#12 ·
Hello
I had asked about a residual valve but was told it may infere with the action of the clutch
My brakes have residual valves (2 psi) but the resovior on the master cylinder is connected to the master. The hyd clutch has the resovoir on the firewall, making it the highest point
The master for the clutch and brakes are floor mounted and behind the pedals
I went out and tried the clutch after my last reply and although it does not appear like a lot of travel, I put it in gear to try it with and without the clutch(board holding down the pedal) It does work ok and I can move the driveshaft with my hands when the clutch is depressed
I do feel happy with this and want to thank you guys for all of your input and advice.
thanks again
Tom
 
#14 ·
I don't think I quite have an inch of travel, but with the tranny in first gear at 2.98:1 and a 4.56 rear gear, I can move the driveshaft easily with my bare hands, once the clutch pedal is depressed
I will be testing in the laneway soon enough. I have to be at the racetrack for Aug 1st
...still lots to do on the car
thanks again
Tom
 
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