Saab 96 V4 long pedal
Discussion
Hi all. Advice please before I look at car scrappage schemes as I am convinced my Saab wants to become a food mixer or some other metal household object. I am currently resurrecting a Saab 96 V4 which came to me as a pile of bits and hadn't run for 15 plus years. I am currently turning it into a rally replica. among the many issues this car has thrown at me, my biggest at the moment is a long brake pedal.
I have fitted new shoes and pads, two reconditioned callipers, new flexi hoses all round. The car came without a brake master cylinder and it took an age to find the correct one as they are unique to these cars. (Lockheed small cap) I managed to get one last year and was assured by the seller (I won't name the business) that it was sound. I have bled the car over and over to no avail. I clamped all four flexi hoses and the pedal still goes to the floor. I have replaced all of the seals twice from a reputable Saab agent. The bore looks fine to me. I was shown how to bleed the cylinder in a vice and I assumed that the piston would be solid. But in fact it moves about 4-5mm before going solid. When I have tried to bleed it again, I seem to get small bubbles in the bleed pipe. I'm wondering if the cylinder has become microporous.
My thinking is the master cylinder has to be duff, has anyone here got any other ideas as I feel I have tried all options now.
If my guess is correct, finding another that is sound is looking even more unlikely, so I wondered if anyone has had any experience of having a cylinder re-sleeved. I'd be interested to know how much it costs.
Finally As I'm not bothered too much about originality as long as it 'looks' the part. I had a strange urge to fit two master cylinders as a brand new pair, since I can buy new ones with a slightly smaller bore for £22 each. I thought it might look a bit 'sexy'. I would have to fabricate a carrier to do this since i've not seen any for sale with out a brake bias adjuster.. As the brakes are plumbed diagonally.
Could any of you guys and gals throw any ideas into the ring please. Many thanks
I have fitted new shoes and pads, two reconditioned callipers, new flexi hoses all round. The car came without a brake master cylinder and it took an age to find the correct one as they are unique to these cars. (Lockheed small cap) I managed to get one last year and was assured by the seller (I won't name the business) that it was sound. I have bled the car over and over to no avail. I clamped all four flexi hoses and the pedal still goes to the floor. I have replaced all of the seals twice from a reputable Saab agent. The bore looks fine to me. I was shown how to bleed the cylinder in a vice and I assumed that the piston would be solid. But in fact it moves about 4-5mm before going solid. When I have tried to bleed it again, I seem to get small bubbles in the bleed pipe. I'm wondering if the cylinder has become microporous.
My thinking is the master cylinder has to be duff, has anyone here got any other ideas as I feel I have tried all options now.
If my guess is correct, finding another that is sound is looking even more unlikely, so I wondered if anyone has had any experience of having a cylinder re-sleeved. I'd be interested to know how much it costs.
Finally As I'm not bothered too much about originality as long as it 'looks' the part. I had a strange urge to fit two master cylinders as a brand new pair, since I can buy new ones with a slightly smaller bore for £22 each. I thought it might look a bit 'sexy'. I would have to fabricate a carrier to do this since i've not seen any for sale with out a brake bias adjuster.. As the brakes are plumbed diagonally.
Could any of you guys and gals throw any ideas into the ring please. Many thanks
Either you have air in the master cylinder, or it's knackered.
I don't know anything about the specific parts you're using. I suggest you need to look at the geometry of the master cylinder and work out where air bubbles will collect in it and whether any of the outlets and/or bleed nipples on it are high enough to get the air out. If the master cylinder has multiple outputs with tandem or floating pistons, it may not be obvious from the outside how to bleed it unless you understand the internal geometry. Depending on the geometry, you may even need to take the m/c off the car and turn it over to chase the air out. (That's something usually associated with calipers and bias valves, but if the m/c acts like it still has air in it after bleeding - maybe you haven't bled it successfully.)
I don't know anything about the specific parts you're using. I suggest you need to look at the geometry of the master cylinder and work out where air bubbles will collect in it and whether any of the outlets and/or bleed nipples on it are high enough to get the air out. If the master cylinder has multiple outputs with tandem or floating pistons, it may not be obvious from the outside how to bleed it unless you understand the internal geometry. Depending on the geometry, you may even need to take the m/c off the car and turn it over to chase the air out. (That's something usually associated with calipers and bias valves, but if the m/c acts like it still has air in it after bleeding - maybe you haven't bled it successfully.)
Thank you for your reply. I have actually bled the master cylinder in a vice several times and I seemed to be getting small air bubbles after a few pumps of the piston. I expected the piston to be rock solid and not have any movement at all as to my mind it should be a perfect hydraulic lock, but I get 4-5mm of movement. This is my 5th Saab and my 3rd 96V4 and I have never struggled like this before to bleed the brakes.I'm still struggling to get hold of a cylinder which is annoying as my project has just ground to a stop now. (even without brakes) So I think I will assume the cylinder is scrap despite it looking okay. I will either investigate having it sleeved or go with my other idea and construct a 'box' and mount two tandem cylinders . Thanks once again.
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