Bench bleeding the TOB
12-13-2014, 05:40 PM
#1
Senior Member
Thread Starter
Bench bleeding the TOB
I know what your thinking...don't bench bleed the TOB because it can cause it to over extend. I'm not talking about introducing any pressure into the TOB. I want to make the bleeding process a little easier by starting out with a TOB that already has fluid inside. If you depress the TOB, when it's released it will create suction. Has anyone attempted to suck fluid into the TOB prior to bolting the trans on the engine? I realize fluid will be forced out of the TOB line when the trans is pushed closer to the engine, in which case, you can simply catch the fluid with a tube connected to clutch pipe routed to a container to catch the expelled fluid. I don't see any risk with doing it this way but would like some input in case I'm overlooking something. This would undoubtedly make bleeding our hydraulic clutch system much easier if TOB was already full.
12-13-2014, 06:16 PM
#3
Senior Member
Thread Starter
Is this with or without the method I posted above? If TOB was already full I wouldn't have to wait for anything at all. Just connect line to TOB pipe and bleed the little bit of air from the line that goes to master cylinder.
12-13-2014, 08:40 PM
#6
Senior Member
Thread Starter
The stock Sachs f40 pressure plate I will be using is self adjusting. I do not plan on doing much bleeding, if any, with the pedal. If TOB is full with little to no air inside I could vaccum bleed at the bleed nipple with my mityvac. That was my plan anyway. Just wondering if anyone has tried this method with success.
01-11-2015, 02:05 PM
#9
Platinum Member
Platinum Member
I'm ironically enough buttoning up a clutch job for a customer at my shop as I type. With that said, don't do it. There's just no need for it. It's easy enough to bleed the system with a vacuum pump. Don't overly complicate it my friend.
01-12-2015, 12:26 PM
#13
Senior Member
Thread Starter
Would you mind giving me a rundown of your step by step bleeding procedure?
01-12-2015, 02:57 PM
#15
Platinum Member
Platinum Member
Simply remove the hard line going into the distribution block (aka elbow) and let it hang as low as you can get it into either a catch can or small bottle.
Next remove the cap from the reservoir and over fill the reservoir a good ways (any excess can easily be drained and/or pumped from the system after words).
With the clutch pedal in the "up" position, simply let the system drain. Within a minute or 2 fluid should start trickling out of the tube.
Once you see a steady stream of fluid coming out, then go ahead and connect the line to the distribution block.
With the line connected, open the bleeder valve on the distribution block and let air and fluid drain for a minute or 2 into a catch can. Once a steady stream starts flowing, go ahead and close the bleeder.
With the bleeder valve closed, connect a vacuum bleeder (the vacuum bleeder MUST have a gauge built into it in order to know how much vacuum is being drawn) and build roughly 20inHG of vacuum. Open the bleeder slowly until you start to see the vacuum pressure drop, and let it continue to drop until stop hearing suction. You should hear a combination of air and fluid come out at this point. Close the valve, and continue with the pump until your catch can is now filling with pure fluid. Just be sure to keep a close eye on your fluid level at all times. Never let it drop below the "Min" mark or you could risk introducing air back into the system.
At that point you should be pretty well bled out. Pump up the pedal a few times and make sure it returns to the top each time. After I vacuum bleed it, I'll usually call over a second set of hands and have them look inside the inspection cover and verify the TOB is cycling properly. I'll also have them pump up the pedal a few times, hold it to the floor, and crack the bleeder with my vacuum pump connected just to verify every bit of air is out of the system. Close the bleeder, reach down to manually pull up the clutch pedal, verify fluid level is good and you should be good to go for a road test.
01-13-2015, 03:45 PM
#16
Senior Member
Thread Starter
Sure. It's actually very easy and really takes no time at all to do. First and foremost, it is very important that, if you are using an adjustable clutch rod, the clutch rod must be COMPLETELY adjusted ALL THE WAY IN (shortest length). If not you run the risk of blocking off the fluid passage from the reservoir to the rest of the lower clutch system.
Simply remove the hard line going into the distribution block (aka elbow) and let it hang as low as you can get it into either a catch can or small bottle.
Next remove the cap from the reservoir and over fill the reservoir a good ways (any excess can easily be drained and/or pumped from the system after words).
With the clutch pedal in the "up" position, simply let the system drain. Within a minute or 2 fluid should start trickling out of the tube.
Once you see a steady stream of fluid coming out, then go ahead and connect the line to the distribution block.
With the line connected, open the bleeder valve on the distribution block and let air and fluid drain for a minute or 2 into a catch can. Once a steady stream starts flowing, go ahead and close the bleeder.
With the bleeder valve closed, connect a vacuum bleeder (the vacuum bleeder MUST have a gauge built into it in order to know how much vacuum is being drawn) and build roughly 20inHG of vacuum. Open the bleeder slowly until you start to see the vacuum pressure drop, and let it continue to drop until stop hearing suction. You should hear a combination of air and fluid come out at this point. Close the valve, and continue with the pump until your catch can is now filling with pure fluid. Just be sure to keep a close eye on your fluid level at all times. Never let it drop below the "Min" mark or you could risk introducing air back into the system.
At that point you should be pretty well bled out. Pump up the pedal a few times and make sure it returns to the top each time. After I vacuum bleed it, I'll usually call over a second set of hands and have them look inside the inspection cover and verify the TOB is cycling properly. I'll also have them pump up the pedal a few times, hold it to the floor, and crack the bleeder with my vacuum pump connected just to verify every bit of air is out of the system. Close the bleeder, reach down to manually pull up the clutch pedal, verify fluid level is good and you should be good to go for a road test.
Simply remove the hard line going into the distribution block (aka elbow) and let it hang as low as you can get it into either a catch can or small bottle.
Next remove the cap from the reservoir and over fill the reservoir a good ways (any excess can easily be drained and/or pumped from the system after words).
With the clutch pedal in the "up" position, simply let the system drain. Within a minute or 2 fluid should start trickling out of the tube.
Once you see a steady stream of fluid coming out, then go ahead and connect the line to the distribution block.
With the line connected, open the bleeder valve on the distribution block and let air and fluid drain for a minute or 2 into a catch can. Once a steady stream starts flowing, go ahead and close the bleeder.
With the bleeder valve closed, connect a vacuum bleeder (the vacuum bleeder MUST have a gauge built into it in order to know how much vacuum is being drawn) and build roughly 20inHG of vacuum. Open the bleeder slowly until you start to see the vacuum pressure drop, and let it continue to drop until stop hearing suction. You should hear a combination of air and fluid come out at this point. Close the valve, and continue with the pump until your catch can is now filling with pure fluid. Just be sure to keep a close eye on your fluid level at all times. Never let it drop below the "Min" mark or you could risk introducing air back into the system.
At that point you should be pretty well bled out. Pump up the pedal a few times and make sure it returns to the top each time. After I vacuum bleed it, I'll usually call over a second set of hands and have them look inside the inspection cover and verify the TOB is cycling properly. I'll also have them pump up the pedal a few times, hold it to the floor, and crack the bleeder with my vacuum pump connected just to verify every bit of air is out of the system. Close the bleeder, reach down to manually pull up the clutch pedal, verify fluid level is good and you should be good to go for a road test.
01-22-2015, 02:07 PM
#18
Senior Member
Thread Starter
Actually he wasn't describing the pedal pump method at all. That method sucks anyway. Minimal pedal pump is the goal here
01-22-2015, 07:25 PM
#20
Platinum Member
Platinum Member
There's the right way for doing things, there's the half assed way of doing things and then there's the guy who things he's clever by explaining away something in one sentence.
Correct procedures tend to need a little more explaining than just a silly 20 word explanation that only states the clear obvious. For those who may not be as familiar with a clutch system, there needs to be more details involved.... especially when the job at hand calls for it. For example: Define "bleed normally with a friend". That means utterly nothing to someone reading this who might actually be looking to learn something. Unfortunately, judging from your simplistic explanation above, I'm guessing you likely have quite a bit more to learn yourself there.
Correct procedures tend to need a little more explaining than just a silly 20 word explanation that only states the clear obvious. For those who may not be as familiar with a clutch system, there needs to be more details involved.... especially when the job at hand calls for it. For example: Define "bleed normally with a friend". That means utterly nothing to someone reading this who might actually be looking to learn something. Unfortunately, judging from your simplistic explanation above, I'm guessing you likely have quite a bit more to learn yourself there.
02-09-2015, 09:39 PM
#21
Your way does sound very sound and thorough. After trying to do it alone yesterday by bleeding it while pumping, i did it by the build book.
Which was as follows and seems fishy..
Connect vac bleeder to resiovior. Mine didnt have an attachment to screw into the cap so i left the cap on and attached to the open 1/4 neck protruding from the top of the res,
Pump vac bleeder to 15, wait for ten minutes.
Relieve pressure, pump clutch 10 or so times, then do it again a few more times waiting 5 minutes in vacum each time.
Idk far as i can tell im feeling normal clutch pedal pressure. But idk how the vac method actually pulls any air.
Which was as follows and seems fishy..
Connect vac bleeder to resiovior. Mine didnt have an attachment to screw into the cap so i left the cap on and attached to the open 1/4 neck protruding from the top of the res,
Pump vac bleeder to 15, wait for ten minutes.
Relieve pressure, pump clutch 10 or so times, then do it again a few more times waiting 5 minutes in vacum each time.
Idk far as i can tell im feeling normal clutch pedal pressure. But idk how the vac method actually pulls any air.
02-10-2015, 10:51 PM
#25
There's the right way for doing things, there's the half assed way of doing things and then there's the guy who things he's clever by explaining away something in one sentence.
Correct procedures tend to need a little more explaining than just a silly 20 word explanation that only states the clear obvious. For those who may not be as familiar with a clutch system, there needs to be more details involved.... especially when the job at hand calls for it. For example: Define "bleed normally with a friend". That means utterly nothing to someone reading this who might actually be looking to learn something. Unfortunately, judging from your simplistic explanation above, I'm guessing you likely have quite a bit more to learn yourself there.
Correct procedures tend to need a little more explaining than just a silly 20 word explanation that only states the clear obvious. For those who may not be as familiar with a clutch system, there needs to be more details involved.... especially when the job at hand calls for it. For example: Define "bleed normally with a friend". That means utterly nothing to someone reading this who might actually be looking to learn something. Unfortunately, judging from your simplistic explanation above, I'm guessing you likely have quite a bit more to learn yourself there.
But I understand people who have never done it before over thinking it and getting themselves psyched up