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Jimmys old Saab
V4 Beginner

United Kingdom
98 Posts

Posted - 17 Apr 2021 :  15:38:06 Show Profile Reply with Quote
I also got around to refitting the calipers to the 96, getting the flexi hoses secured to the pesky brackets on the inner wings is a massive ballache :)
So I started, with some assistance on bleeding, front nearside and rear offside produced some results, with fluid leaking out, however the pedal remained very floppy and after multiple tries nothing could be made to come out of the front offside and rear nearside bleed nipples.
I'm guessing that one part of the dual circuit is not working due to damaged seals in the master cylinder?
I also realise that some systems are an absolute pig to get the air out of, is the V4 an especially difficult one?

Saab 96 1971
Datsun 120y coupe 1975
Saab 9000 CSE turbo 1993
VW T5 LWB 2012

GeoffC
V4 Fanatic

United Kingdom
482 Posts

Posted - 18 Apr 2021 :  23:33:09 Show Profile Reply with Quote
Sounds like a problem in the master cyl. I always used an easy bleed system on the rally car but they shouldn't be difficult to do. The only time I had a problem amd failed to get a firm pedal it turned out to be a leak in one of the back cylinders, so there is usually a reason if you can't bleed them well.
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christophe
V4 Fan

France
114 Posts

Posted - 20 Apr 2021 :  20:18:41 Show Profile Reply with Quote
I just overhauled my calipers and changed the front brake hoses which dated back from 1978. I had no problem whatsoever when bleeding the front brakes and it was not necessary to touch the rear ones. I used a bleeding check valve and it did the work perfectly. If your master cylinder proves faulty, don't forget to check for brake fluid in the booster. Best of luck.
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melle
V4 Guru

United Kingdom
3342 Posts

Posted - 21 Apr 2021 :  07:25:02 Show Profile Reply with Quote
Err, there shouldn't be any brake fluid in the booster! As the others said, 96 brakes are normally very easy to bleed.

www.saabv4.com
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christophe
V4 Fan

France
114 Posts

Posted - 21 Apr 2021 :  08:35:51 Show Profile Reply with Quote
Melle, I am sorry if I exprssed myself incorrectly. Of course, there must be no brake fluid in the booster. I mentioned this because I found plenty of it in mine. It seems to me that few people bother with this when changing a leaking master cylinder.
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melle
V4 Guru

United Kingdom
3342 Posts

Posted - 21 Apr 2021 :  08:44:59 Show Profile Reply with Quote
Oops, sorry for misreading!

www.saabv4.com
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christophe
V4 Fan

France
114 Posts

Posted - 21 Apr 2021 :  10:32:35 Show Profile Reply with Quote
Don't worry about this. My English is far from being perfect and I can make some "bizarre" sentences from time to time. On the bright side of things, my 96 should be roadworthy again today and the weather forecasts are very good. Unfortunately, we still got the 10 km radius limit. So, I will have to be imaginative. Nice day to all.
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EdinburghJoe
V4 Fan

United Kingdom
119 Posts

Posted - 21 Apr 2021 :  14:41:51 Show Profile Reply with Quote
Interesting point about brake fluid in the servo: my master cylinder leaked quite a bit of fluid (before I had it relined) and I think it may have got into the servo, but I could see no way to check: the aperture on mine where the master cylinder fits into it had an inverted cap on it with a very narrow hole, just wide enough for the operating rod.

I know from speaking to Andy Deans that they aren't all like that: he told me his servo basically had an open hole that was plugged by the master cylinder.

So on the plus side it would have been harder for fluid to get into my servo, but I can't see how to get it out. Or indeed even be sure that there is any in there.

So far my approach has been to just leave it alone!
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EdinburghJoe
V4 Fan

United Kingdom
119 Posts

Posted - 21 Apr 2021 :  14:51:36 Show Profile Reply with Quote
To get back to Jimmy's post: I've always used an Easibleed and it works well, but you need to keep the pressure low(ish) - maybe 10-15 PSI to avoid possible damage to the master cylinder seals.

If you've been using the peddle to bleed the system then the brake pedal will be moving through its full travel - ie much further than usual. This can mean it scrapes up crud and corrosion that has remained undisturbed during normal usage, which can knacker the seals (I've never done this, but I have been warned!). Again, the easibleed avoids this possibility.

I don't think the Saab is particularly difficult to bleed. I had problems on our Golf with flexible pipes bent in an 'n' - shape - the air gathers at the top, and the fluid flow from the Easibleed wasn't enough to flush it through. In the end I removed the caliper and held it vertically above, but I don't think this is an issue on the Saab.

Good luck!
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melle
V4 Guru

United Kingdom
3342 Posts

Posted - 21 Apr 2021 :  17:15:42 Show Profile Reply with Quote
quote:
Originally posted by EdinburghJoe
If you've been using the peddle to bleed the system then the brake pedal will be moving through its full travel - ie much further than usual. This can mean it scrapes up crud and corrosion that has remained undisturbed during normal usage, which can knacker the seals (I've never done this, but I have been warned!).
I've never experienced this with brakes, but I have with clutches (both V4 and 900). For the last few years I've also been using Eezibleeds, never had a problem again.

www.saabv4.com
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SAAB96L
V4 Beginner

United Kingdom
98 Posts

Posted - 21 Apr 2021 :  17:36:49 Show Profile Reply with Quote
Hello Joe,

A classic sign of brake fluid in some servos will be the burning of brake fluid seen clearly as excessive exhaust smoke - quite spectacular in some cases !! The vacuum hose pulls the fluid from the servo into the inlet manifold, which more often than not is due to a defective diaphragm - although I'm not certain as to the internal set-up on the 96 servo. But generically, that is the case.

Regards.

Richard.
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christophe
V4 Fan

France
114 Posts

Posted - 21 Apr 2021 :  21:28:30 Show Profile Reply with Quote
I came to the conclusion that some brake fluid had leaked into the booster because my car got a strange (acid) smell at the exhaust. I took quite a lot out of it by using a long rubber hose and a vacuum pump through the vacuum port. You can also stuff a length of cloth by the same port and let it soak for a while. I did this this very afternoon as I wanted to check my system after doing the front brakes. Unfortunately, brake fluid is back, so I have a master cylinder repair kit in my future! Nice evening to all.
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Jimmys old Saab
V4 Beginner

United Kingdom
98 Posts

Posted - 01 May 2021 :  21:44:23 Show Profile Reply with Quote
Had a very thorough attempt to get the brakes working again today, using a decent brake bleeding kit. Still problems though.
The nearside front and offside rear bled fine but the other two corners produce no brake fluid. The level of fluid drops only in the rear portion of the fluid reservoir.
I guess this means that there is a problem with the master cylinder? There is no external leak but maybe fluid is not getting to one of the two circuits because of a damaged internal seal. Can someone point me in the direction of the correct kit? My car is a 1971/72.

Saab 96 1971
Datsun 120y coupe 1975
Saab 9000 CSE turbo 1993
VW T5 LWB 2012
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green96v4
V4 Mad

Canada
591 Posts

Posted - 02 May 2021 :  12:49:15 Show Profile Reply with Quote
John Saab has the repair kits, sells them on eBay - he does both large and small cap reservoir kits (not sure which one your is as it's in that change over window, mine is a 71 and had the large cap, but I changed to the later as I was told the large cap BMC is garbage)

https://www.ebay.co.uk/usr/john-saab?_trksid=p2047675.l2559
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EdinburghJoe
V4 Fan

United Kingdom
119 Posts

Posted - 05 May 2021 :  17:34:50 Show Profile Reply with Quote
I had a problem with one of Johns BMC seal kits (small cap type)- theres one seal which is deeper than the others and this part was missing. In the end I got a kit from Speedy Spares in Brighton, which totally matched what was on the car. Every other kit Ive got from John Saab was fine though, so I think this might have been a one off.
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Jimmys old Saab
V4 Beginner

United Kingdom
98 Posts

Posted - 19 May 2021 :  22:18:27 Show Profile Reply with Quote
Well I got one of John's kits and apart from a pair of thin washers it all matched up nicely to the large cap Lockheed master cylinder.
Taking that cylinder apart wasn't quite as bad as purported to be, neither my circlip pliers nor my friends collection of high end kit would do the job but in the end I managed with a pair of small, slotted, Wiha screwdrivers.
Having put it all back together....not much joy. I have bled all four corners using a good blake bleeding kit and have sunk about 500ml of fluid into the system but the front offside and rear nearside brakes will still not bleed. What is going on? Maybe I'm just under estimating the volume of fluid the system contains and just need to continue but I have been around each corner a half dozen times!

Saab 96 1971
Datsun 120y coupe 1975
Saab 9000 CSE turbo 1993
VW T5 LWB 2012
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