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Discussion Starter #1
Hello again.

This is something I have already searched and have not found a solution for.

I am trying to bleed my LT1 clutch and slave as it is all new.
I have tried 3 different slaves and this is the second line I have tried. All are new. I have 3 masters and two of them I know are good which is why I am using one of them.

To bleed the clutch system, you have to pump multiple times. Though my issue is I have been doing it for about two hours, and still nothing is working. I have removed the slave cylinder and tried bleeding it by holding it up right or even pushing in the push rod back into the slave but still no luck. The pedal is not dead weight, it has pressure but not enough.

Does anyone have any useful tips for getting this thing bled?
 

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Are you doing the bleeding with the slave cylinder lower than the master cylinder? This is essential for proper bleeding.

Also slave should be positioned vertically with the rod facing down.

Another instruction from factory manual is, before you start bleeding push the rod approx 0.800 inches in and put the diaphragm & cap on the reservoir while holding the rod in. After putting cap on you release the rod.

Then it push rod in and out until no more bubbles appear.

Kinda makes you wish GM had put a bleeder valve on there.
 

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Discussion Starter #3
Are you doing the bleeding with the slave cylinder lower than the master cylinder? This is essential for proper bleeding.

Also slave should be positioned vertically with the rod facing down.

Another instruction from factory manual is, before you start bleeding push the rod approx 0.800 inches in and put the diaphragm & cap on the reservoir while holding the rod in. After putting cap on you release the rod.

Then it push rod in and out until no more bubbles appear.

Kinda makes you wish GM had put a bleeder valve on there.
I appreciate the reply.

The master is higher than the slave even when I pulled the slave off.
For the diaphragm/cap, I apologize for not understanding but are you talking about the cap to the master reservoir?
If so, I can try this tonight to see if it will work. Its pretty easy for my to remove the slave as my transmission tunnel is cut out to make a custom one.

I purchased one from Oreilly's that has a bleeder on it but it doesn't get here until friday. If I can get the one I have working, would be great so I can get my money back for the new one.

Thank you. I will try after work and will update this thread once done to see if it works or not.
 

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FWIW I have done it with success....although with the entire hydraulic system out of the car. My car is a B-body so my MC is completely inside the car built into my custom clutch pedal and I have a hole in tunnel to pass the slave through.

For on the car bleeding I did do once with success. slave must be hanging and use "short" pumps, not full stroke. Also make sure no pressure of pedal is on MC. I just got a shock cord and used it on pedal to seat to hold it up. That way the MC is "open" and will allow air to escape up to resovoir

would be great if LT1 systems did have bleed provisions like LS "push" type hydraulics do.

I just put in McLeod Twin disc clutch which requires a larger bore MC (13/16") as the clutch kit includes it. Nice piece made my Wilwood. BUT no bleed provision either.

I bought a new (O'Rileys) slave (exact same brand as OEM) and first bench bleed the slave by holding it verticle in vice with a short piece of clear hose I had over the open end. filled slave, short pumps and watched all the bubbles come up/out the clear piece of hose I put on end. Once all air was out I removed the small clear hose (it was full of fluid also which left the slave "completely" full, even above the point where the pin goes through it to hold the braided steel line to.

now the MC. I had it out of the car (actually had my whole clutch pedal assembly out but you can just have MC out as F-body you can install system as one unit). I rigged up a spare resovoir on top, MC with steel line attached that was in a plastic bottle to catch the brake fluid (like you would use to bleed brakes). Filled MC as much as possible first (my Wilwood/Mcleod has a cap on it, stock ones don't) first then attached the resovoir and catch bottle to line. pumped, filled, pumped about a pt of fluid through until all bubbles were gone. Now the tricky part was connecting the line between MC & slave together without introducing any air. I cut the plastic bottle so now it was a "cup" with fluid with line still submerged. put my thumb over end of line and pulled it out and "quickly" put it in the slave in while it was help verticle in vise. Yeah there would still be a tiny amount of air introduced when making this connection. a few pumps from the now attached slave while it was hanging lower than anything else and the last air bubble came out. Solid hydraulics ever since.

Some have had success with a Mighty Vac from above in resovoir, for me that just sucked all the fluid out even at 5 PSI.

Bleeding the sealed LT1 hydraulics is a PIA but can be done.
 

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Discussion Starter #6
Tried what you said Cocobolo95, still nothing when I install it back in. There is pressure but not a lot. Still the same.
 

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Is the clutch fork in the right position? You will not get the proper pressure on the pedal unless everything is lined up right. If the fork has slipped off the throwout bearing it will be hard to push the pedal. (I know from experience)
 

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Discussion Starter #8
When I pulled the slave earlier, I thought the same thing since I removed the transmission not too long ago but it is in the right position as far as I remember.

Just in case though, is there a way to test this?

When the slave was out, I pulled the fork down as if you were removing the transmission and pushed it back in to double check.
 

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We might have to jump to the conclusion that old master and/or slave is no good. When new one gets there you can find out.

Glad I got to jump to that conclusion as it's the only exercise I get nowadays.:D
 

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Discussion Starter #11 (Edited)
So I may be possibly doing this wrong. Friend of mine who read the ad said I may be doing it differently than what is recommended.

Are you recommending that I remove the slave and hold it up right with the push rod facing down, then pump the pedal Or pump push the rod in? I was pumping the push rod.
 

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When I pulled the slave earlier, I thought the same thing since I removed the transmission not too long ago but it is in the right position as far as I remember.

Just in case though, is there a way to test this?

When the slave was out, I pulled the fork down as if you were removing the transmission and pushed it back in to double check.

fork should look like pic below when on TO bearing right

and NEVER push clutch pedal with slave removed....you will immediately blow the slave out if you do this.

Pump slave piston by hand with slave pointing down to bleed.
 

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Discussion Starter #15 (Edited)
Thats how my fork looks. On another thread, they were talking about a fork issue not mounting to the throw out bearing but I dont think that is my issue as everything worked before in the old car and is all mounted the same. I pulled the fork out as if you were removing the tansmission and pushed it back in, seems to only be able to go back in at one point. A bit of play on it. How easy should it be able to slide in?
Should it be easy to push the fork with a pry bar to try and engage the clutch by hand? I cant seem to be able to do it so was wondering.

Just bought my 4th slave, its a metal one this time but same setup basically. Hopefully it works. The one that was suppose to get here thursday I guess had a different fitting for the line that doesnt use the pin.

I tried mounting the slave on without the metal spacer and installed it all the way. Doesnt seem it has enoug pressure to push the fork back. Tries but isnt able to do it.

Also, just want to inform that the strap I had that held in the push pin was broke when I got the most recent part. Only one side was holding.
 

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The plastic straps on the slave are supposed to break on the first push. sometimes only 1 breaks but they both should. the plastic cup needs to stay on the end of the slave rod

don't remove the spacer and try to bolt the slave closer.

your MC could be weak or you still need to bleed air out of the system
 

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Discussion Starter #18
I tested the master and line, line you can blow easily through both of them. The new slave has a bleeder on it I am told.
Bahnhof Clutch slave

Just waiting for it to come in and then I will try again. Hopefully it works this time. If it doesn't, I think I will pull the engine out to figure out what is wrong in the transmission or something other than the clutch slave.
 

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Discussion Starter #20
It's difficult to determine if the master or slave are bad, that's why some folks replace them both with a pre-bled assembly. Have you thought about doing that? Found this one at RockAuto. More Information for AMS AUTOMOTIVE PS0427
My master is completely different than that.
The car is a 240sx. I can try buying another master as well since they are pretty cheap just I am very sure that these two work as one is from the old car that the engine was swapped in and worked, the other was in the car I have now that worked before the engine blew. I have a third one but it was already uninstalled so not sure if it works or not. Haven't tested it yet.
 
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