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OWEN
V4 Fanatic

United Kingdom
318 Posts

Posted - 20 Dec 2019 :  13:20:28 Show Profile Reply with Quote
No pressure on clutch pedal. Checked resevoir. Empty! Topped up and bled. Worked fine, drove over a few days. Checked level again; no loss of fluid. Parked up for a few days, then......... no pressure on clutch pedal. Reservoir empty. How the hell can that happen? It doesn't lose fluid under pressure but empties under no pressure! What's happening? If the seals are gone in the slave would it syphon the reservoir empty? Do I renew seals on the Master or slave cylinder?

Iain G
V4 Fan

United Kingdom
159 Posts

Posted - 20 Dec 2019 :  14:44:32 Show Profile Reply with Quote
Is the fluid running out the bottom of master and down onto the clutch pedal arm in the driver's footwell?

Iain G
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V4saab1966
V4 Fanatic

United Kingdom
252 Posts

Posted - 21 Dec 2019 :  00:59:26 Show Profile Reply with Quote
Hi had the same experience as ian said check his suggestion or replace the seals on both slave and master cylinder as I did ,this way you will definitely resolve the problem, normally when one fails the other isn’t to far behind , pays you to do both at the same time then you have no issues again.
I did mine as a complete unit on the garage floor on a cardboard sheet, assembled it all and bleed it as a assembled unit off the car .
Refitting is a bit of a fiddle but it’s already bled #128077;#128077;
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OWEN
V4 Fanatic

United Kingdom
318 Posts

Posted - 21 Dec 2019 :  10:16:32 Show Profile Reply with Quote
Wise words V4saab1966. I've ordered both sets of seals. Bleeding it out of the car (no garage, so kitchen!) is a good idea as I have no 'assistant' for bleeding it. Looks like it'll be after Christmas now though. I've found a replacement slave cylinder which has been dry for years and seems to be seized. I've filled it with fluid in the hope of loosening it. Any tips or tricks for freeing it up?
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melle
V4 Guru

United Kingdom
3830 Posts

Posted - 21 Dec 2019 :  11:25:42 Show Profile Reply with Quote
Compressed air; but please stick it between vice jaws so the piston has nowhere to go when it breaks free.

www.saabv4.com
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OWEN
V4 Fanatic

United Kingdom
318 Posts

Posted - 21 Dec 2019 :  13:37:34 Show Profile Reply with Quote
Thanks Melle
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Iain G
V4 Fan

United Kingdom
159 Posts

Posted - 22 Dec 2019 :  08:18:33 Show Profile Reply with Quote
Definitely agree with Paul.
Do the whole system and bleed it off the car.

Iain G
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EdinburghJoe
V4 Fan

United Kingdom
162 Posts

Posted - 23 Dec 2019 :  13:04:11 Show Profile Reply with Quote
Hi Owen, I had a similar problem with my brakes a couple of years ago: fairly major fluid loss from the master every now and then, usually happened at winter and always when the car was left in the garage for a week or so. It never lost fluid when being driven.
There was a scuff of wear on the inside of the master cylinder, just where the seal sits in the open end, so occasionally the seal wouldn't do its job properly and fluid would slowly trickle out. I suspected a new seal would not work because of the 'scuff', so in the end I got it re-sleeved (by 'Past Parts'), put new seals in and (fingers crossed) no more leaks!
I think you'll need to be careful with any replacement cylinder that has seized - however you get the piston out it's likely that the bore might not be in good condition. Last time I looked Malbrad had new master and slave cylinders. Not cheap of course, but maybe the best option if you do have wear in either bore.
For what it's worth, on my seized 'spare' master I eventually freed it with lots of penetrating fluid, and put an old screwdriver STRAIGHT down through the 'fluid out' end of the cylinder and hit it with a hammer. Not pretty, but it did work. As expected, the bore was in a sorry state with corrosion, so I'm not sure how useful this cylinder will ever be...

Joe
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EdinburghJoe
V4 Fan

United Kingdom
162 Posts

Posted - 23 Dec 2019 :  16:24:34 Show Profile Reply with Quote
One other thing came to mind: when I had a problem with my clutch (this was a totally separate issue to the one with the brake I mentioned earlier) I tried bleeding it with an easibleed, only to find the fluid going straight out the 'open end' of the cylinder and down onto the pedal. I'd never had leaks before.

When I replaced the seals I found that the one at the 'open end' was flared side towards the open end, which was what was allowing the fluid to escape. It didn't affect the operation of the clutch because the other seal was the other way round, so it would hold pressure. When I reassembled it I put both seals flared side away from the open end. This seemed to work: I could pressure bleed it with no leaks.

Not sure how it was 'supposed' to be set up, but it does seem to be happily working...
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OWEN
V4 Fanatic

United Kingdom
318 Posts

Posted - 28 Dec 2019 :  17:07:26 Show Profile Reply with Quote
Fixed it by following Paul's advice, removing the whole system from the car, replacing seals in both master in slave, bleeding and reinstalling in the car. Found some interesting stuff; The spring in the master cylinder had deteriorated into three pieces, so it was still 'springing' but not to its full extent. Luckily I had 2 old master cylinders to scavenge. One turned out to have a larger bore; not sure what vehicle it was from (looked the same externally). The second was from a 1976 V4 and had a different arrangement of seals and spring. Rather than scavenge from this, I replaced the seals in it and used it (the repair kit comes with 3 seals so is obviously designed to repair both types and you end up with one spare seal). I replaced the seal in the slave as well (and used the master to pump the piston out of the slave so as not to damage the cylinder by hammering it!). The result is a pedal with a much higher biting point. I'm now wondering if the last time I replaced the clutch, I may not have needed to; it could be that the master was not moving enough fluid to move the slave enough to operate the clutch. I guess the test would be to check the length of the 'throw' in the slave before replacing the clutch (no idea what that throw should be though). I'm guessing the loss of fluid was due to both the master and slave seals not sealing and the fluid syphoning from the slave (sometimes!). What a fiddly job! Only advice I can give is when replacing the clevis pin on the clutch pedal, push it in from the left (where you have more space RHD) and use a long piece of wire instead of a split pin; then you can bend the wire and cut the excess off; otherwise it's a bugger to fit the clevis pin.
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V4saab1966
V4 Fanatic

United Kingdom
252 Posts

Posted - 05 Jan 2020 :  13:36:36 Show Profile Reply with Quote
Hi Owen glad you have sorted it like you said the Clevis pin is the point where it can be tricky I used a split pin as I found it easier than the clevis pin so I can second that issue you encountered.
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melle
V4 Guru

United Kingdom
3830 Posts

Posted - 05 Jan 2020 :  15:13:43 Show Profile Reply with Quote
There is usually a lot of slop in the clevis joint after 40-50 years of use, with a noticeable effect on the clutch action. I have on a few cars remedied this by truing up the holes in the cylinder arm and the pedal with a reamer and using a larger diameter custom clevis pin, or by partially welding up the holes and filing them back to size. On my 900 I recently installed a bronze bush in the clutch pedal as I had no lathe or welder available; not sure from memory if there's enough meat for this mod on a 95/96 pedal. Also the brake pedal an the throttle linkages (especially if the car still has the original FoMoCo coat hanger wire set-up) will benefit from tightening up the tolerances. Do the brakes first as you may need them when you find a few extra hp after doing the throttle!

www.saabv4.com

Edited by - melle on 05 Jan 2020 15:16:44
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