Working on the SM

the only way I could get the range rover here to bleed its clutch was to crack the bleed nipple on the slave.... and using a new oil can, pump the fluid backwards filling the master cylinder from the slave.
 
Another way to bleed a hydraulic clutch is to pressurise the master cylinder via a reservoir of fluid. Open the slave nipple and the fluid is quickly forced through, taking any bubbles with it. You do need to make a special cap for the master cylinder reservoir, but this is the only way I was able to bleed my 944 clutch. It has a spring assisted clutch pedal, which makes bleeding the normal way more difficult.
 
My theory is that air prefers to float up tubes to a higher level than to flow down tubes to a lower level, especially if it is intermittant flow.

Cheers, Ken
 
Ken W said:
My theory is that air prefers to float up tubes to a higher level than to flow down tubes to a lower level, especially if it is intermittant flow.

Cheers, Ken
Click to expand...
Ken, IIRC from my Peugeot ownership days, about the only way to successfully bleed the hydraulic clutch on a 504/505 was to loosen or remove the clutch master cylinder cap, connect a hose from the LF (the closest on a 504/505) brake bleed nipple to the clutch slave cylinder bleed nipple, open both bleed screws, then 'reverse' bleed the clutch by pumping the brake pedal until the air bubbles in the clutch master cylinder reservoir stopped. Of course, care needed to be taken to catch any overflow at the top end. Like many things, simple when you know how!! Is this problem/methodology just a French idiosyncrasy I wonder?
Cheers, Robin
 
Robin Hoffmann said:
Ken, IIRC from my Peugeot ownership days, about the only way to successfully bleed the hydraulic clutch on a 504/505 was to loosen or remove the clutch master cylinder cap, connect a hose from the LF (the closest on a 504/505) brake bleed nipple to the clutch slave cylinder bleed nipple, open both bleed screws, then 'reverse' bleed the clutch by pumping the brake pedal until the air bubbles in the clutch master cylinder reservoir stopped. Of course, care needed to be taken to catch any overflow at the top end. Like many things, simple when you know how!! Is this problem/methodology just a French idiosyncrasy I wonder?
Cheers, Robin
Click to expand...

Its really easy if you use the oil can trick. Buy a new oil can (so its not tainted with oil). Drain the master/slave so you have removed all the old moisture laden fluid. Fill the new oil with brake fluid/lhm/whatever your system used.

TOLEDO 500ml Oil Can Lever Type 305259

Heavy duty multipurpose oil can for all miscellaneous lubricaiton work both professional and DIY. Specifications Type: Lever type with rigid & flexible spout Capacity: 500ml Spout size rigid: 150mm Spout size flexible: 175mm
www.totaltools.com.au

I used something like this. Now hook the can to the slave bleeder and "fill" the master cylinder from the slave. When the master is full, you should have a working clutch :) The fluid has pushed all the air up and out as you filled it.
 
I've had difficulties with bleeding many cars and bikes over the years. As long as there is some hydraulic pressure present, I push the pedal down as far as I can, jam a stick between the pedal and the seat and leave it overnight. With bikes I squeeze the lever in tight, zip tie it to the handlebar and again leave it sit overnight.
As long as there is some pressure in the system the bubbles will usually work their way up to the master cylinder by morning.
 
Ken W said:
My theory is that air prefers to float up tubes to a higher level than to flow down tubes to a lower level, especially if it is intermittant flow.
Click to expand...
Indeed they do, if left to their own devices, but by pressurising the reservoir, the fluid is forced to flow faster towards the slave, when the bleed nipple is opened, than the bubbles can rise against that flow. So instead of the master cylinder pumping the bubble laden fluid to the slave bleed nipple, as you would traditionally do, slowly, the pressurised reservoir does it for you, quickly.
 
DoubleChevron said:
Its really easy if you use the oil can trick. Buy a new oil can (so its not tainted with oil). Drain the master/slave so you have removed all the old moisture laden fluid. Fill the new oil with brake fluid/lhm/whatever your system used.

www.totaltools.com.au

TOLEDO 500ml Oil Can Lever Type 305259

Heavy duty multipurpose oil can for all miscellaneous lubricaiton work both professional and DIY. Specifications Type: Lever type with rigid & flexible spout Capacity: 500ml Spout size rigid: 150mm Spout size flexible: 175mm
www.totaltools.com.au www.totaltools.com.au

I used something like this. Now hook the can to the slave bleeder and "fill" the master cylinder from the slave. When the master is full, you should have a working clutch :) The fluid has pushed all the air up and out as you filled it.
Click to expand...
Clearly the old adage still holds true: there's more than one way to skin a cat. Keeping it still and avoiding the claws is what's important. Cheers, Robin
 
Robin Hoffmann said:
Clearly the old adage still holds true: there's more than one way to skin a cat. Keeping it still and avoiding the claws is what's important. Cheers, Robin
Click to expand...
That's for sure. I didn't come up with the "use an oil can" thing. I was googling "I can't bleed my clutch" and found the oil can suggestion on a car forum somewhere. I'm certainly not smart enough to have come up with it myself :) As soon as you hear about it though ..... its so obvious you wonder why you didn't do it straight away rather than messing around for hours trying to bleed the mongrel thing :clown:
 
Surprised you get any kind of seal between oil can and bleed nipple - sounds as if it'd be like me trying to get grease into a grease nipple!
 
Armidillo said:
Surprised you get any kind of seal between oil can and bleed nipple - sounds as if it'd be like me trying to get grease into a grease nipple!
Click to expand...
there isn't any pressure involve, just run a bleeder line from the nipple to the oil can. I probably just used a bit of brake bleeder tube :)
 
DoubleChevron said:
there isn't any pressure involve, just run a bleeder line from the nipple to the oil can. I probably just used a bit of brake bleeder tube :)
Click to expand...
You will need to seal the nipple thread with tape or you'll end up with fluid on the floor. Same goes if you use a vacuum pump to draw the fluid through to the slave.
 
Engenia said:
You will need to seal the nipple thread with tape or you'll end up with fluid on the floor. Same goes if you use a vacuum pump to draw the fluid through to the slave.
Click to expand...
it possible, I didn't have that problem. You will introduce leakage rather than air bubbles in this case though :)
 
Get a cheap garden sprayer to make a pressure bleeder. Disconnect and plug the hose from the LHM tank and pressure bleed the clutch system. Works every time.
Clutch master pressure bleeder.jpg
 
that's an easy way to make a pressure bleeder. Most cars you need a variety of master cylinder caps for. So expensive pressure bleeders probably wouldn't work on most of the cars I own :)
 
The last few days I've been watching the ever increasing diameter of the LHM stain on the concrete under the middle of the SM. Yesterday I opened the bonnet to have a look around and there was a deep pool of freshish LHM siting on the top of the gearbox. I managed to get a rag in there and clean it up a bit and I started the engine up and you can see the results in the picture below. The bottom of the bellows on the steering rack have fresh LHM on them so I suspect one or both have failed and the LHM is now emptying out on the top of the rearbox rather then being returned to the reservior??? or should it not be leaking into this space like it is??? I cannot feel any splits in the bellows and the clamshells behind the centre steering point do not look like they would hold LHM anyway. Perhaps the bellows are only there to keep dust out?

So it looks like the steering rack has to come out and then to bits to replace the bellows and what ever other seals are worn. Any ideas on what parts I might need? I have the RL Bachelor PDF files x 2 on servicing the rack but pointers to any other doco would be welcome.


LHM on top of Gearbox.jpg


Cheers, Ken
 
This could be an interesting one. Is it a DS rack or CX rack internally :confused: I'm sure John T has been down this road before, maybe start a new thread called "SM steering racks" so he will see it ?

I couldn't believe my eyes yesterday, I was driving down a local road and an SM blurred past. I think that is the first time I've ever seen an SM on the road (ever) outside of a club event. They look like nothing else on the roads coming towards you.
 
I think the SM rack is essentailly the same as a DS one. In either case the bellows are just there to keep dust out, any LHM collection is incidental. The rack isn't meant to leak any fluid so if the bellows are filling up then the rack seals are failing. It's not a quick job to fix and the rack needs to come out and be totally dismantled.
 
Thanks Faulksy. I had come to that conclusion but I couldn't 'Like' your post. I will have to get the new aircon compressor into the Activa and replace the LHM return pipe I broke changing the expansion valve so I can transfer the SM into the best working position in the shed.

Who knows where this job will end. I already have to put new seals into both the front brake calipers and I know the front suspension bump stops are pretty destroyed. I think the tie rods from the bottom of the steering relays to the pivots are OK but there are some suspension rattles that only happen over a series of bumps that I haven't tracked down as yet so I should check the relays as well.

Cheers, Ken
 
Ken W said:
Thanks Faulksy. I had come to that conclusion but I couldn't 'Like' your post. I will have to get the new aircon compressor into the Activa and replace the LHM return pipe I broke changing the expansion valve so I can transfer the SM into the best working position in the shed.

Who knows where this job will end. I already have to put new seals into both the front brake calipers and I know the front suspension bump stops are pretty destroyed. I think the tie rods from the bottom of the steering relays to the pivots are OK but there are some suspension rattles that only happen over a series of bumps that I haven't tracked down as yet so I should check the relays as well.

Cheers, Ken
Click to expand...

How hard would it be to just put a drip tray under it :clown: I find once I pull cars to bits .... that's it, they are in bits "forever". It drives me crazy! (maybe that's only me though).

At least everything won't break on the SM just because you have breathed near it, like the > 1980's cars. I can remember stuff breaking on the xantia years ago when it was quite young. Just because you were silly enough to try and repair something nearby.
 
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