slave cylinder bleeding how to help.. please

[burgermeister]

Originally Posted by deep_uv

....
The car tilting thing makes no sense to me. You don't do that when you bleed the brakes, right? This is no different. Just pump fluid through it until you have no more bubbles and don't let the reservoir go below half full in the process.

Regards,

The slave cylinder is a horizontal unit with the bleeder screw in the front. If the rear of the car is higher, the bleeder screw will not be at the highest point of the cylinder, leaving room for an air bubble towards the rear.

With the calipers, the bleeder screw is at the top of the caliper regardless of orientation (within reason ...)

[Dixie]

Bob,

I presume you've confirmed the slave is no longer leaking, and the push-rod is seated in the clutch fork? Have you verified the master, under the toe-board, is also not leaking?

[imcarthur]

Here's what it looks like:



Here's what John Walker told me:

"you don't need any fancy equipment. put a short 7mm box end wrench on the bleeder, attach a drain hose aimed at a pan, open bleeder a 1/4 turn, pump the pedal all the way down and slowly back up a few times, wait a few seconds between pumps, stop with the pedal all the way up, go under and close the bleeder and then test the pedal to be sure it feels normal. same way you do a one man brake bleed. i've used suction and pressure bleeders and had limited luck. usually could not get a decent pedal. sometimes you get lucky. just because the fluid comes out with them, doesn't mean it's going to work. not sure why, but the hand pumping always works."

In this post: Can you put a speed bleeder on a clutch?

And he was right. His method worked & the Motive failed.

Ian

[deep_uv]

Originally Posted by imcarthur

Here's what it looks like:



Here's what John Walker told me:

"you don't need any fancy equipment. put a short 7mm box end wrench on the bleeder, attach a drain hose aimed at a pan, open bleeder a 1/4 turn, pump the pedal all the way down and slowly back up a few times, wait a few seconds between pumps, stop with the pedal all the way up, go under and close the bleeder and then test the pedal to be sure it feels normal. same way you do a one man brake bleed. i've used suction and pressure bleeders and had limited luck. usually could not get a decent pedal. sometimes you get lucky. just because the fluid comes out with them, doesn't mean it's going to work. not sure why, but the hand pumping always works."

In this post: Can you put a speed bleeder on a clutch?

And he was right. His method worked & the Motive failed.

Ian

Interesting. That's not my experience. I've bled my clutch slave with the Motive many times (in conjunction with brake bleeding before track events) and never had a problem. I had just as much flow as what came out of the calipers. Never had to do any pumping or tilting to get good results.

Regards,

Steve

[wastintime]

Yeah, this is starting to sound more like you might have an issue with the slave cylinder if it was leaking to begin with, and now you've just introduced a high pressure flow of fluid to it that might have made a problem worse. It's entirely possible the slave cylinder is sucking air in through wherever it's been leaking.

[rcaradimos]

Originally Posted by Capt. Carrera

Bob,

I presume you've confirmed the slave is no longer leaking, and the push-rod is seated in the clutch fork? Have you verified the master, under the toe-board, is also not leaking?

With fluid under pressure w/ power bleeder no leaks out of the slave, I haven't checked the master.. the leak was coming from the slave before cleaning and reassembling. The push-rod is seated on the fork correctly

I'll run a pint of fluid tonight and post whats going on.
Thanks everyone, it appears everyone has different methods and results based on how much air is in the system. I think I introduced allot of air in the system buy using the motive dry, so I have to look at it like I have multiple pockets of air in the system. I'll do a wet pressure bleed tonight.

[rcaradimos]

All set guys, thanks
I pushed some fluid through the system with the motive power bleeder (filled w/ a quart).
After some blazing saddle action, I closed the bleeder to test the pedal and it firmed up some. The next thing I did was pump the clutch pedal several times with the power bleeder sill attached, then under the car to open the bleeder again to release any other air that I moved around in the system and I did get some out. I did that two more times then the pedal felt pretty good. Reinstalled the line bracket, rubber view cover that exposes the push-rod and clutch fork ear. Disconnected the power bleeder and clamp on the over flow tube.
Put the tire back on and lowered the car for the test drive. All is good.
Kitty littered the garage floor, now if everything stays dry I'm going to be satisfied with my work. Down the road if I have to replace the slave It should go pretty quick now that I have the experience.
Again thanks for your help guys

[rnln]

I am confused. If you open the bleeder valve, then pump the pedal. Soon you release the pedal up, isn't air will be sucked into the system through the opened bleeder valve?

Originally Posted by imcarthur

Here's what it looks like:



Here's what John Walker told me:

"... open bleeder a 1/4 turn, pump the pedal all the way down and slowly back up a few times, wait a few seconds between pumps, stop with the pedal all the way up, go under and close the bleeder ..."

Ian

[imcarthur]

You have to move reseaonably quickly. I had a wrench on it (wedged up because the weight of the wrench closed it). Do the pumping by hand leaning into the car, then quickly close the wrench - fluid is still coming out as you close it from what I remember. The Motive just didn't produce a confident stream of fluid the way it does for brakes from my experience.

My pedal is nice & firm.

Ian

[wastintime]

as long as the system is under pressure it is impossible to allow air in... same with using a powerbleeder for brakes... you can pump the brakes all you want while bleeding them with a power bleeder becasue air annot come back into the system, it's usefull too when you're trying to replace the entire fluid volume.

[rnln]

Oh I thought you meant doing it the manual way. If you are doing it with the power bleeder, I thought you don't need to pump the pedal anymore?

[rcaradimos]

After doing lots of research this is what I found out, it seems like Beck Arnley makes 5 or 6 rebuild kits for slaves used on German cars etc. and get this Toyota pickup trucks. You can do a Internet search on Beck Arnley slave cylinder rebuild kits to check it out. Our host sells the part under the 928 section 928-116-901-00-OEM Rebuild Kit for Clutch Slave Cylinder, 924/944 All (1977-91), Each
Brand: Genuine Porsche $22.75.
I installed the cup seal that comes w/ this kit in my slave cylinder after my leak came back one week after my cleaning and replacing the part. When I took the old cup seal off it was worn, dry and brittle with some hair-line cracks that was allowing the fluid to pass by. The cylinder and piston were fine no scratches or any ware. Tip: put new seal in hot water to soften up, it will be more pliable to put on the piston.

[rnln]

I had the same thought, looking for rebuild part, when I opened up my old slave. Mine car is an 87 with a G50 tranny but the slave doesn't look the same as yours. Mine has a piston, a big spring, and a rubber o-ring seal; which goes over the piston. What makes the slave leak is the rubber o-ring. If I can find that o-ring, problem solved.
In your pic above, I don't see the piston and that o-ring. And on my slave, I don't have all those parts beside the spiral lock washer.

[rcaradimos]

rnln,
Mine is a 87 G-50> top right is the cup seal that goes on the piston.


This is how my slave looked off the car.

The brass ring holds the small end of the dust boot to the push rod, the large gear looking washer holds the large end of the dust boot against cylinder casting, the little cap is for bleeder. I didn't use any of those parts because mine were in good shape.
The cup seal goes on the piston with the view you see in the picture facing the spring in the cylinder, as fluid comes into the slave from the feed line.. pressure pushes against the cup seal keeping the outer edge of seal tight on cylinder wall. I'm not sure if a O-ring would work. Inner Diameter 16mm OD 24mm 6mm wide. The diameter of the cup seal is tapered wider on the side you see in the picture by about 1mm. Put the spring in cylinder first, piston next with wider tapered end of seal going into cylinder next.

[rnln]

umm... the slave on my car look the same, except for the cup seal on yours. Mines are just the o-ring. It goes on the grove on the piston. It won't expand the way your cup seal works. It just slide against the cylinder wall. It does have a big spring inside the cylinder.
Anyway, how much that kit cost you? I got the new slave for around $100 bucks because I couldn't find the kit or o-ring anywhere.

[rcaradimos]

under 30$ with shipping

928-116-901-00-OEM Rebuild Kit for Clutch Slave Cylinder, 924/944 All (1977-91), Each
Brand: Genuine Porsche $22.75. available from our host

70$ in my pocket > close to 250% return on investment with sustainable responsibility until I run the savings though the injectors; about 500 miles of pleasure... priceless

[rnln]

I know what to do next time. Thanks Bob.

[burgermeister]

rcaradimos, you get 500 miles from $70 of gas? Pretty darn good ... or you get cheap 93 octane. Love your analysis either way

Thanks for the part number - I'll keep it stored away someplace where I won't find it when I need it... even better, I'll add this:

clutch slave cylinder rebuild kit part number g50 hydraulic forgot

And maybe now search will find it for me. Hahahaha - take that, lousy brain - I don't need you anymore!

(I need some coffee this morning - and soon.)

[rcaradimos]

burgermeister
LOL
25mi per gal @ $3.50... 87octane the good stuff, My car is from California and has the retarded spark like me burning 87 the car runs better. I think if your timing is advanced by way of a chip you need to use the 91+ I'm happy with the performance on this 187K motor.. no need to mix drinks on the old girl she could puke on me and that wouldn't be fun.