B20 build - Page 11

Amazonjulian · Mar 17th, 2016, 06:13

Morning - yes fluid was coming through Derek. The clamp I used was the approved girling tool which clamps the hose between two chromed rods. I am going to replace the hose in any case.... It's not too expensive and it rules out another issue. I did incidentally fit a new copper washer to the slave end of the hose when reassembling.

Amazonjulian · Mar 26th, 2016, 10:02

I don't know whether I'm more embarassed or frustrated. Since I last posted, I have replaced the hose, the master and slave cylinders were already new brookhouse items. Schoolboy error- thrust rod not properly adjusted. That done and I had half a pedal but still not enough movement. Checked the clevis on the pedal- all good. The system is so thoroughly bled that if I open the bleed nipple, the fluid just runs out without pumping. ( can that be right?) in any case I still don't have a clutch and other than that my new engine is ready to start up. Is there anything else I'm missing? Can that free running fluid be right?

Derek UK · Mar 26th, 2016, 12:38

New or not I'm going to assume the MC is working properly. You shouldn't assume, but if you take the hose off the slave, the fluid should squirt out consistent amounts of fluid into a jar and empty the MC pot with a regular drop in level with each pump. I know it's wasteful but make sure that happens the same for 2 or 3 pots of fluid. The MC shouldn't drain by itself with the pedal in the up position. Some people do gravity bleed the system with the pedal depressed with the slave end wide open. This is more suitable for a completely new and clean system which yours more or less is. With the pedal up fluid will drain out the bottom until it's stopped by vacuum. You can see what happens if you fill up a length of clear tube with water and then block one end and lower the open end.. Some water will come out but not much. Any air bubbles in the tube will tend to rise to the top and that will allow more water out. This would also happen if you have any bubbles in the hydraulic fluid. That's the reason you don't reuse the fluid that you've pumped through the system. Doing high pressure squirts tends to form micro bubbles and these combine over time to give much bigger bubbles which can be indicated by a spongy pedal . Much more obvious with brakes and shouldn't be a problem with what is a small amount of fluid in a simple clutch set-up.
Back to the chase. With the pedal still down after checking that the MC is working consistently reattach the slave and put the bleed hose back onto the slave bleeder. The bleeder should be properly open, if you take it right out you'll see how it works with a hole in the side of the cone. The bleeder shouldn't be sloppy/loose as that can cause air to be sucked back in via the threads. If you have any red rubber brake grease a bit of this on the treads will help and even ordinary grease at a pinch even though it isn't really compatible with brake fluid. When set-up, pedal up and down straight away. If you are using the self bleed rubber tube you can then make a few easy pumps while keeping an eye on the fluid level in the pot. The pedal should feel a bit heavier but the level in the MC pot should go down in the same increments as before. If you are doing it the 2 person way with just a plain tube you will need to tighten the bleeder at the bottom of each stroke which is tedious and a good reason to use the bleeder tube with the split! All things being equal after a few more pedal pumps the system should be bled. Yes we've heard that before somewhere.

You mention the push rod adjustment. Whilst bleeding the push rod won't be doing much as there is no pressure to push it, the pressure is leaking away with the fluid of course. Don't try and bleed the system with no clearance, or worse, reverse pressure on the pushrod. Loosen nuts first, see further on. With the system now hopefully bled it's time to adjust the rod. Volvo in their wisdom made the nuts as difficult as possible to adjust and lock up. I use some very thin bicycle spanners which fit these nuts when locking them up after the adjustment has been made. Best to screw the lock not out of the way and back towards the slave. Then screw the cone nut back an inch or so too. A small pair of mole grips is useful to stop the rod from turning as the threads usually have a bit of corrosion on them. You can take the spring off at the clutch arm if you want but it tends then to fall off the other end. With it off it does make it easier to adjust the clearance. The amount of play should be very small, about 3/32". Can be an 1/8" even 1/16" but there must be some play. We'll come to adjustment at the foot pedal end later but the clearance you set here will also set the bite point of the clutch at the pedal. 3/16" to an 1/8" will mean that the clutch will start to bite near to the floor but that will also mean that you have to fully depress the pedal when changing gear otherwise the change will be stiff and obstructive. Reducing the clearance brings the bite point higher off the floor and can be adjusted to your preference. Adjusted right the gearstick should click across the gate like a Toyota (!) with just a small dip of the pedal. If you drive someone else's car the first thing you notice if it's badly set up is the clutch bite. Instantly stalling when pulling away when the clutch bites half an inch off the floor is the usual sign but at the other extreme you let the clutch out and then out some more and nothing happens until you get to the point you think you're still in neutral and then you stall it when it suddenly bites with your knee touching the steering wheel.
Back to the pedal end. When both the pedals, brake and clutch are set correctly the pedal pads should be level. There are plenty of illustrations in the manuals about the distance the pads should be off the floor but importantly the pedal arm for the clutch shouldn't be off the floor when fully depressed. If it is it can put a stain on the MC internals. If you have sound deadening under your mats or thick carpets the pedal arm might touch the surface quite hard but it mustn't bottom out mechanically at the MC. They can both be adjusted at the clevis. Loosen lock nut, pull out the fiddly split pins, pull out the cotter and the pedal will move out towards you via its spring. You can only do half turn adjustments so think about what you need. Adjust the clutch pedal to the book and level up the brake one if needed. Put everything back together again. Lock the nuts and fit new split pins or R clips.
Note: The clevises can wear badly, especially the clutch one, making for a lot of slop at the pedal. Replacing them gives back the new feel to the pedals. When badly worn the clutch pedal can loose a lot of its useful movement and so a very good idea to replace at least that one. Not too many years ago theses weren't available but now easy from Simon or the other usual suspects.

Ramblings over............ Good luck.

Amazonjulian · Mar 26th, 2016, 14:10

Many thanks for all your time with this derek. Enormously helpful. The fact that the master cylinder empties out with the bleed screw open ... Notwithstanding the suggested pressure tests must then indicate a problem with the unit?
The bleed screw does feel sloppy in fit so that's another thing to look at. There are no visible bubbles coming through though.

mocambique-amazone · Mar 26th, 2016, 18:29

Hello Julian, the master cylinder should empty out with bleeding screw open, this is ok!
I don't understand your problem.
Does the sleeve cylinder move out if the master is pressed?
Are you able to measure the hub?
I don't remember the diameter of master and slave and I have no manual here in the nowhere to have a closer look.
Does the release fork move by pedal or not?
The Engine didn't run till now?
If everything is new the pedal feels spongy, standart.
Is the release fork the newer version? May the fork is bent? The old one are prone to get the owner angry.

Happy eastern, Kay

Amazonjulian · Mar 27th, 2016, 09:47

Thanks Kay. The slave rod moves but not far enough to disengage the clutch. No problems with the fork. Not enough pressure on the pedal. Travel on the slave is only 17mm. Adjustment on slave is correct and pedal is set correctly. I'm going to follow Derek's advice to make sure the master cylinder is giving me full pressure. I think it is but I need to be systematic as this has been a very persistent problem. All the symptoms suggest that the system isn't fully bled but at the moment I can't get any visible bubbles through. I'll get there... It's just very frustrating

mocambique-amazone · Mar 27th, 2016, 10:52

Hello Julian, 17mm should be enough.
17mm travel on sleeve is a little bit more than 19mm on master.

Master is 19mm in diameter, sleeve should be 21.5mm.
I can't remember travel on master and my amazone is just 300km
away.

Did you run the engine?
If the engine is running, the clutch doesn't open?
Maybe you have a proplem in the clutch, not in the hydraulic system

Happy eastern, Kay

volvogv · Mar 27th, 2016, 16:22

SPEED MAN! SPEED!
You have to have one man on the pedal "pump/release" and one man on the bleeder. It's the same as bleeding brakes only faster:

- Push the pedal down HARD.
- Open the bleeder (fluid gushes out)
- close bleeder quickly.
- release pedal
- repeat, repeat.

I cannot overemphasize the need for SPEED. There's a bubble that gets trapped at the top up the "U" bend. The object is to push it down and out faster than it can rise through the viscous fluid. Every time you pause the bubble will start to rise. DO NOT PAUSE!

The man on the bleeder gives the commands and it's really helpful to have a 3'rd man to top off the reservoir.

Derek UK · Mar 28th, 2016, 00:56

Julian. Check this thread re slave travel. 17mm is too small.
Did you fit a new clutch? Was it a matching 3 piece, maybe from Brookhouse or was it made up of parts. Using the wrong release bearing can cause problems. One bad combination causes too little adjustment and the other too much adjustment. Possibly yours is the former if wrong. Where is the cone adjuster nut, is it right out at the end of the pushrod?

http://www.volvoforums.org.uk/showth...ush+rod+length

Amazonjulian · Mar 28th, 2016, 06:36

Morning. In response to your points Derek, the release bearing was separate from the rest of the kit as it happens. When fitting, I checked carefully to make sure the dimensions were the same as the original. It's obviously a consideration but having said that I'm not yet feeling the hydraulic pressure that I should be. A friend in the trade is bringing me round a vacuum bleeder today so that should confirm or eliminate air as the issue. I checked the flow from the master cylinder as you suggested and it was strong and regular.

Mar 17th, 2016, 06:13	#101
Amazonjulian Master Member Last Online: May 8th, 2019 07:02 Join Date: Feb 2010 Location: Steyning	Morning - yes fluid was coming through Derek. The clamp I used was the approved girling tool which clamps the hose between two chromed rods. I am going to replace the hose in any case.... It's not too expensive and it rules out another issue. I did incidentally fit a new copper washer to the slave end of the hose when reassembling.

Mar 26th, 2016, 10:02	#102
Amazonjulian Master Member Last Online: May 8th, 2019 07:02 Join Date: Feb 2010 Location: Steyning	I don't know whether I'm more embarassed or frustrated. Since I last posted, I have replaced the hose, the master and slave cylinders were already new brookhouse items. Schoolboy error- thrust rod not properly adjusted. That done and I had half a pedal but still not enough movement. Checked the clevis on the pedal- all good. The system is so thoroughly bled that if I open the bleed nipple, the fluid just runs out without pumping. ( can that be right?) in any case I still don't have a clutch and other than that my new engine is ready to start up. Is there anything else I'm missing? Can that free running fluid be right?

Mar 26th, 2016, 12:38	#103
Derek UK VOC Member Last Online: May 2nd, 2024 16:48 Join Date: Jul 2006 Location: Chatham	New or not I'm going to assume the MC is working properly. You shouldn't assume, but if you take the hose off the slave, the fluid should squirt out consistent amounts of fluid into a jar and empty the MC pot with a regular drop in level with each pump. I know it's wasteful but make sure that happens the same for 2 or 3 pots of fluid. The MC shouldn't drain by itself with the pedal in the up position. Some people do gravity bleed the system with the pedal depressed with the slave end wide open. This is more suitable for a completely new and clean system which yours more or less is. With the pedal up fluid will drain out the bottom until it's stopped by vacuum. You can see what happens if you fill up a length of clear tube with water and then block one end and lower the open end.. Some water will come out but not much. Any air bubbles in the tube will tend to rise to the top and that will allow more water out. This would also happen if you have any bubbles in the hydraulic fluid. That's the reason you don't reuse the fluid that you've pumped through the system. Doing high pressure squirts tends to form micro bubbles and these combine over time to give much bigger bubbles which can be indicated by a spongy pedal . Much more obvious with brakes and shouldn't be a problem with what is a small amount of fluid in a simple clutch set-up. Back to the chase. With the pedal still down after checking that the MC is working consistently reattach the slave and put the bleed hose back onto the slave bleeder. The bleeder should be properly open, if you take it right out you'll see how it works with a hole in the side of the cone. The bleeder shouldn't be sloppy/loose as that can cause air to be sucked back in via the threads. If you have any red rubber brake grease a bit of this on the treads will help and even ordinary grease at a pinch even though it isn't really compatible with brake fluid. When set-up, pedal up and down straight away. If you are using the self bleed rubber tube you can then make a few easy pumps while keeping an eye on the fluid level in the pot. The pedal should feel a bit heavier but the level in the MC pot should go down in the same increments as before. If you are doing it the 2 person way with just a plain tube you will need to tighten the bleeder at the bottom of each stroke which is tedious and a good reason to use the bleeder tube with the split! All things being equal after a few more pedal pumps the system should be bled. Yes we've heard that before somewhere. You mention the push rod adjustment. Whilst bleeding the push rod won't be doing much as there is no pressure to push it, the pressure is leaking away with the fluid of course. Don't try and bleed the system with no clearance, or worse, reverse pressure on the pushrod. Loosen nuts first, see further on. With the system now hopefully bled it's time to adjust the rod. Volvo in their wisdom made the nuts as difficult as possible to adjust and lock up. I use some very thin bicycle spanners which fit these nuts when locking them up after the adjustment has been made. Best to screw the lock not out of the way and back towards the slave. Then screw the cone nut back an inch or so too. A small pair of mole grips is useful to stop the rod from turning as the threads usually have a bit of corrosion on them. You can take the spring off at the clutch arm if you want but it tends then to fall off the other end. With it off it does make it easier to adjust the clearance. The amount of play should be very small, about 3/32". Can be an 1/8" even 1/16" but there must be some play. We'll come to adjustment at the foot pedal end later but the clearance you set here will also set the bite point of the clutch at the pedal. 3/16" to an 1/8" will mean that the clutch will start to bite near to the floor but that will also mean that you have to fully depress the pedal when changing gear otherwise the change will be stiff and obstructive. Reducing the clearance brings the bite point higher off the floor and can be adjusted to your preference. Adjusted right the gearstick should click across the gate like a Toyota (!) with just a small dip of the pedal. If you drive someone else's car the first thing you notice if it's badly set up is the clutch bite. Instantly stalling when pulling away when the clutch bites half an inch off the floor is the usual sign but at the other extreme you let the clutch out and then out some more and nothing happens until you get to the point you think you're still in neutral and then you stall it when it suddenly bites with your knee touching the steering wheel. Back to the pedal end. When both the pedals, brake and clutch are set correctly the pedal pads should be level. There are plenty of illustrations in the manuals about the distance the pads should be off the floor but importantly the pedal arm for the clutch shouldn't be off the floor when fully depressed. If it is it can put a stain on the MC internals. If you have sound deadening under your mats or thick carpets the pedal arm might touch the surface quite hard but it mustn't bottom out mechanically at the MC. They can both be adjusted at the clevis. Loosen lock nut, pull out the fiddly split pins, pull out the cotter and the pedal will move out towards you via its spring. You can only do half turn adjustments so think about what you need. Adjust the clutch pedal to the book and level up the brake one if needed. Put everything back together again. Lock the nuts and fit new split pins or R clips. Note: The clevises can wear badly, especially the clutch one, making for a lot of slop at the pedal. Replacing them gives back the new feel to the pedals. When badly worn the clutch pedal can loose a lot of its useful movement and so a very good idea to replace at least that one. Not too many years ago theses weren't available but now easy from Simon or the other usual suspects. Ramblings over............ Good luck.

Mar 26th, 2016, 14:10	#104
Amazonjulian Master Member Last Online: May 8th, 2019 07:02 Join Date: Feb 2010 Location: Steyning	Many thanks for all your time with this derek. Enormously helpful. The fact that the master cylinder empties out with the bleed screw open ... Notwithstanding the suggested pressure tests must then indicate a problem with the unit? The bleed screw does feel sloppy in fit so that's another thing to look at. There are no visible bubbles coming through though.

Mar 26th, 2016, 18:29	#105
mocambique-amazone Master Member Last Online: Jan 24th, 2022 17:08 Join Date: Nov 2008 Location: small village in the north of Germany	Hello Julian, the master cylinder should empty out with bleeding screw open, this is ok! I don't understand your problem. Does the sleeve cylinder move out if the master is pressed? Are you able to measure the hub? I don't remember the diameter of master and slave and I have no manual here in the nowhere to have a closer look. Does the release fork move by pedal or not? The Engine didn't run till now? If everything is new the pedal feels spongy, standart. Is the release fork the newer version? May the fork is bent? The old one are prone to get the owner angry. Happy eastern, Kay

Mar 27th, 2016, 09:47	#106
Amazonjulian Master Member Last Online: May 8th, 2019 07:02 Join Date: Feb 2010 Location: Steyning	Thanks Kay. The slave rod moves but not far enough to disengage the clutch. No problems with the fork. Not enough pressure on the pedal. Travel on the slave is only 17mm. Adjustment on slave is correct and pedal is set correctly. I'm going to follow Derek's advice to make sure the master cylinder is giving me full pressure. I think it is but I need to be systematic as this has been a very persistent problem. All the symptoms suggest that the system isn't fully bled but at the moment I can't get any visible bubbles through. I'll get there... It's just very frustrating

Mar 27th, 2016, 10:52	#107
mocambique-amazone Master Member Last Online: Jan 24th, 2022 17:08 Join Date: Nov 2008 Location: small village in the north of Germany	Hello Julian, 17mm should be enough. 17mm travel on sleeve is a little bit more than 19mm on master. Master is 19mm in diameter, sleeve should be 21.5mm. I can't remember travel on master and my amazone is just 300km away. Did you run the engine? If the engine is running, the clutch doesn't open? Maybe you have a proplem in the clutch, not in the hydraulic system Happy eastern, Kay

Mar 27th, 2016, 16:22	#108
volvogv Master Member Last Online: Aug 29th, 2016 19:28 Join Date: Oct 2013 Location: Seattle	SPEED MAN! SPEED! You have to have one man on the pedal "pump/release" and one man on the bleeder. It's the same as bleeding brakes only faster: - Push the pedal down HARD. - Open the bleeder (fluid gushes out) - close bleeder quickly. - release pedal - repeat, repeat. I cannot overemphasize the need for SPEED. There's a bubble that gets trapped at the top up the "U" bend. The object is to push it down and out faster than it can rise through the viscous fluid. Every time you pause the bubble will start to rise. DO NOT PAUSE! The man on the bleeder gives the commands and it's really helpful to have a 3'rd man to top off the reservoir.

Mar 28th, 2016, 00:56	#109
Derek UK VOC Member Last Online: May 2nd, 2024 16:48 Join Date: Jul 2006 Location: Chatham	Julian. Check this thread re slave travel. 17mm is too small. Did you fit a new clutch? Was it a matching 3 piece, maybe from Brookhouse or was it made up of parts. Using the wrong release bearing can cause problems. One bad combination causes too little adjustment and the other too much adjustment. Possibly yours is the former if wrong. Where is the cone adjuster nut, is it right out at the end of the pushrod? http://www.volvoforums.org.uk/showth...ush+rod+length

Mar 28th, 2016, 06:36	#110
Amazonjulian Master Member Last Online: May 8th, 2019 07:02 Join Date: Feb 2010 Location: Steyning	Morning. In response to your points Derek, the release bearing was separate from the rest of the kit as it happens. When fitting, I checked carefully to make sure the dimensions were the same as the original. It's obviously a consideration but having said that I'm not yet feeling the hydraulic pressure that I should be. A friend in the trade is bringing me round a vacuum bleeder today so that should confirm or eliminate air as the issue. I checked the flow from the master cylinder as you suggested and it was strong and regular.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)