Midas Cars Forum - www.midascarsforum.com

I've never looked inside this type of servo but as I understand it a vacuum is maintained on both sides of the diaphragm until you brake, when air is admitted to the pedal side. Therefore the end of the m/c is always under vacuum, so air could not enter by that route. The present servo works much better (not saying much!) than the previous one, but I didn't have this problem with the old one, it just didn't do much servo-ing.

It's a good job I've got a sense of humour. This weekend I've changed both calipers and the master cylinder and bled it all round three times. Result - zero pressure, pedal just goes straight to the floor. Incidentally, given the well-known tendency of air bubbles to rise, I wonder why the rear cylinders have the bleed nipple at the bottom. Or has my car been assembled upside down?

mine are the same geoff. I am sure its correct that way or how is the handbrake going to work?

Geoff Butcher wrote:It's a good job I've got a sense of humour. This weekend I've changed both calipers and the master cylinder and bled it all round three times. Result - zero pressure, pedal just goes straight to the floor. Incidentally, given the well-known tendency of air bubbles to rise, I wonder why the rear cylinders have the bleed nipple at the bottom. Or has my car been assembled upside down?

Geoff, how do you bleed? I tried it on my own, but still got problems. Apparently air can be sucked back in via the bleed valve thread. With a second person pressing and holding the brake pedal (and releasing it when I had closed the bleed nipple) all pipes were quickly bubble free. Also keep the right order as per the Haynes manual. There are several possibilities depending on the version of the brake system you have.

Hans Efde wrote:

Geoff Butcher wrote:It's a good job I've got a sense of humour. This weekend I've changed both calipers and the master cylinder and bled it all round three times. Result - zero pressure, pedal just goes straight to the floor. Incidentally, given the well-known tendency of air bubbles to rise, I wonder why the rear cylinders have the bleed nipple at the bottom. Or has my car been assembled upside down?

Geoff, how do you bleed? I tried it on my own, but still got problems. Apparently air can be sucked back in via the bleed valve thread. With a second person pressing and holding the brake pedal (and releasing it when I had closed the bleed nipple) all pipes were quickly bubble free. Also keep the right order as per the Haynes manual. There are several possibilities depending on the version of the brake system you have.

At the risk of teaching my granny to suck eggs...
I used to bleed my Midas's brakes using an air reservoir to pressurise the master cylinder, having ensured the fluid level was as high as possible. As I'm sure you know, there are kits to do this, and it's possible to use an inflated tyre as an air supply, but I think I used a coolant tank from a Citroen together (or it might have been a windscreen washer tank from a Beetle?), together with a modified master cylinder cap - it had a piece of 3/16" brake pipe brazed into it - connected with a suitable length of rubber pipe.
With the brake system pressurised, you don't need to go near the brake pedal, just go round the bleed valves in turn, opening the valves until the bubbles have gone. You do need to do a frequent check of the brake fluid level though, but since I started using this method, I've never needed to employ an assistant.

I've never used a pressure device since the Day of the Great Reservoir Explosion. (shudder). I'm doing it on my own, but I make sure the the plastic tube goes up from the nipple so it keeps a head of fluid, which should stop any air getting sucked back in. I never have any trouble with my Ginetta with this method. There must be quite a lot of air still in there for the pedal to hit the floor after three bleeds, but I'm getting bubble-free fluid out, so where can this air be? I'm following the sequence given in the Haynes book for a post-85 although I'm damned if I know what difference it makes.

I think you're going to try the easybleed again, just watch the pressure. I've had no trouble since my one and only explosion, think I run it at around 10psi

Geoff Butcher wrote:I've never used a pressure device since the Day of the Great Reservoir Explosion. (shudder). I'm doing it on my own, but I make sure the the plastic tube goes up from the nipple so it keeps a head of fluid, which should stop any air getting sucked back in. I never have any trouble with my Ginetta with this method. There must be quite a lot of air still in there for the pedal to hit the floor after three bleeds, but I'm getting bubble-free fluid out, so where can this air be? I'm following the sequence given in the Haynes book for a post-85 although I'm damned if I know what difference it makes.

This is exactly how I tried and I had the same problem. Liters and liters of brake fluid and still bubbles. My friend Ed explained to me that air is sucked in via the threads while you release the brake pedal and get out the car to close the valve, so it won't work. You have to keep positive pressure on the brake system before closing the bleed valves. Just ask somebody, I suppose you're not the reincarnation of Robinson Crusoe are you?

Today I have been mostly bleeding brakes. Another two laps, jamming the pedal down with a piece of wood before closing the nipples, and very good exercise it is , too, pant, gasp. Result - a little pressure there now, but nowhere near good enough yet. Something puzzled me while I was doing all this, no matter which nipple is open, the pedal always goes down the same amount, i.e. just about on the floor. Since these are dual circuit brakes, surely if a rear nipple, say, is open, the secondary circuit should still be doing its stuff, if not there isn't much point in having two circuits. When I had the rear fail on my MK2 I had no trouble in stopping it, with a bit harder shove and an audible clunk from the master cylinder.
I have a horrible feeling I'll be off to buy a new eezibleed tomorrow. Oh, joy...

Hi,

It might be worth checking your pipe runs to make sure it's all hooked up properly one of the fixed pipes on mine was hooked up the wrong way round on the caliper so the bleed sequence was out. Also remember that you don't always have full travel on the pedal in a Midas even if the pedal has been tweaked. On my car the only way to get a good pedal was with an easy bleed, it spent 4 weeks in a garage with them trying to bleed it I did in about 2 hours with a little help from the missus. I also found I got a better result by holding the pipe attached to the nipples vertical it seemed to tease the last of the air out.

Cheers,

Mike