Have bleeded brakes but still get no tension at the pedal and hearing air at the pedal , the reservoir for fluid went down overnight , does this mean a leak or maybe a master cylinder?

Try bleed

1. Check the fluid level in the master cylinder. ...
2. Locate the bleed screw on the slave cylinder. ...
3. Attach the hose to the bleed screw. ...
4. Open the bleed screw on the slave cylinder. ...
5. Have a friend press the clutch pedal in and hold it. ...
6. Close the bleed screw. ...
7. Have your friend release the clutch pedal.

Bleeding Clutch by Blocking the Slave Cylinder

Disconnect battery ground 1st.(dont wanna send computer anything new) Find the bleeder valve on backside of caliper,its lil brass bolt,10mm wrench usually,and has a hole n center. If u can get to these on the ground and tires on,itll save ya that much more time. Check ur brake fluid reservoir,keep it full,check after each tire bleed. DO NOT LEAVE CAP OFF WHILE BLEEDING,Hopefully ya left it on when collapsing cylinder to replace pads. Once ya have all that done ya need some 1 n drivers seat,and some 1 at bleeder valve,have them pump brake pedal,minimum 6 times,and then hold brake pedal dwn,once its held all the way dwn,brake loose the bleeder valve bout 1/2 turn,enuff to let air out and fluid, to where ya start seeing brake fluid,keeping pedal dwn tighten up valve,now repeat from pumping pedal,and hold down,loosen valve,till pedal has stooped going anyfurther dwn,tighten up valve,release pedal. Now ya should only have to do this a few times,depending on a few factors. Check all disk brakes this way,also REMEMBER TO CHECK FLUID AFTER BLEEDING EACH WHEEL,OR IF U HAVE BLED IT alot and have had alot of fluid going through valve,check sooner. YOU DONT WANNA RUN OUT IN RESERVOIR,AS YOULL BE BLEEDING BRAKES FOR HOURS INSTEAD OF 30mins.
Keep reservoir full
Pump pedal and hold
Break loose bldr valve,ask if pedal went down.
Always tighten valve B4 releasing pedal
Repeat,till each brake has straight fluid coming out.
Repeat for all disk brakes on car, ??The brake fluid reservoir,often if bleeding alot through calipers.
Hope helps mostly way i try n descibe what to do.

If the master cylinder is replaced, care must be taken to prime the new master cylinder by removing all of the air and completely filling it with brake fluid. The spongy feeling is air that is still in the circuits. You will need to bleed the back brakes as well as the front ones again. The order that you bled them seems correct, but perhaps there remained some air in the main trunk lines.

For the best results 2 people are needed. Start at the further distance wheel cylinder and bleed at least three (3) master cylinder reservoir volumes of fluid (back brakes). Bleed the fluid with use of a piece of tubing attached to the bleed port that is long enough to reach almost to the bottom of a long neck or tall clear jar (clear drink bottle works well). When the bleeding begins, after one or two brake pedal pushes, make sure that the end of the tubing is below the surface of the fluid and keep it under. It best to have a clear bleed line (to observe air). Keep pumping the brake pedal while being careful to not completely empty the master cylinder reservoir (leave 1/4 full always). Repeat the same technique for each wheel cylinder with at least two (2) reservoirs full for front brakes. Partially close the bleed ports when almost finished (at least 5 pedal strokes without exit of any air). Completely close the ports during the down stroke of the brake pedal, with the tubing still attached. Be sure each bleed port is closed snuggly.
Most of the brake fluid can be reused, but not the darker portion at the bottom of the jar.

does the pedal have pressure then go down after valve is cracked? With a hose on the nipple to a bottle to catch the fluid, press rear brake pedal down. Don\'t pump the brakes. Crack the bleeder valve while continuing to press down on the pedal. Once the pedal reaches the limit of its travel close the valve. Once the valve is closed; and not before; release the pedal and let it return to its at rest position. Repeat this process until you have good pedal without the need to pump, good clean fluid is coming out the valve, and no air is in the fluid coming out the valve. Be sure not to let the fluid in reservoir get too low or you will suck in air and need to start over and don\'t press the pedal too quickly or you can shoot a stream of brake fluid out the reservoir.

In very extreme cases, if you have lost prime in the master cylinder, it may be necessary to bleed the master cylinder first. THIS IS A LAST RESORT. Remove the brake line from the master cylinder. Try to limit the loss of fluid from the brake line to bare minimum. Thread a nipple into the master cylinder. Run a hose from the nipple into the reservoir. Be sure the hose stays submerged in the fluid in the reservoir and pump the brake until no bubbles come out the hose. Remove the nipple and reinstall the brake line. Slowly press down the brake pedal while tightening the line to minimize the air bubble in the brake line. Again be sure not to release the pedal until the line is tight. Then proceed to bleed the brakes as you normally would. Do not pump the brakes up. Just press the pedal down, crack the valve, close the valve, release the pedal, repeat.

GRAVITY BLEEDING CLUTCH HYDRAULIC CIRCUIT

1. Verify fluid level in brake master cylinder. Top off with DOT 3 brake fluid as necessary. Leave cap off.

2. Raise vehicle on hoist.

3. Remove bleed port protective cap and install suitable size and length of clear hose (4) to monitor and divert fluid into suitable container.

4. Open up the bleed circuit by turning the thumb screw (3) counter clockwise this will start the air purge and fluid fill process.

5. Lower vehicle, but only enough to gain access to and fill the brake master cylinder. NOTE: Do not allow clutch master cylinder to run dry while fluid exits bleed port.

6. Top off brake master cylinder fluid level while air is purged and fluid drains from bleed port. Continue this until no air bubbles are seen and a solid column of fluid exists.

7. Close hydraulic bleed circuit, remove drain hose and replace dust cap on bleed port.

8. From driver's seat, actuate clutch pedal 60-100 times.

9. Apply parking brake. Start engine and verify clutch operation and pedal feel. If pedal feels fine and clutch operates as designed, stop here. If pedal still feels spongy or clutch does not fully disengage, excessive air is still trapped within the system, most likely at the master cylinder.

10. Top off brake master cylinder fluid level with DOT 3 brake fluid as necessary.

POWER BLEEDING CLUTCH HYDRAULIC CIRCUIT

1. Remove reservoir cap and connect bleeder cap to reservoir. NOTE: Use Bleeder Cap/Modified reservoir cap adapter Snap-on #901-059 or equivalent.

2. Connect service filling machine to bleeder cap. NOTE: Use Service Filling Machine/Brake power bleeder Brake power bleeder or equivalent.

3. Service filling machine should be pressurized to at least 2.5 bar (36 PSI).

4. Remove dust cap from bleeder valve and connect the transparent bleeder hose to bleeder valve.

5. Place the other end of hose in the bleeder container to capture the used fluid. The end of the hose MUST be submerged in the DOT 3 brake fluid.

NOTE: Use Bleeder Container To capture hydraulic fluid and Transparent Bleeder Hose To route fluid to container.

6. Turn on the service filling machine.

7. Crack open the bleeder valve (3).

8. Allow fluid to flow out of bleed port until no more air bubbles can be seen in the transparent bleeder hose.

9. Once fluid is free of air bubbles; make 15 quick actuations between clutch pedal stop positions.

10. Close the bleeder valve and disconnect the service filling machine.

11. To remove remaining air, actuate pedal 10 times slowly between pedal stop positions.

12. Check clutch pedal to see if vehicle is properly bled.

13. If vehicle is not properly bled, repeat procedure.

14. Remove bleeder cap from reservoir and replace reservoir cap.

15. Disconnect transparent bleeder hose from bleeder valve and replace dust cap.

1. Check the fluid level in the reservoir after bleeding each wheel. Add DOT3 fluid, if necessary.
2. If the master cylinder was disassembled or if the reservoir becomes empty, bleed the air from the master cylinder as follows:
   1. Disconnect the brake lines from the master cylinder.
   2. Slowly depress the brake pedal and hold it.
   3. Block off the outlet plug with your finger, and release the brake pedal.
   4. Repeat 3 or 4 times.
   
   
3. Bleed the brake starting with the one furthest from the reservoir and then the next furthest, etc.
   
4. Depress the brake pedal several times, then loosen the bleeder plug with the pedal held down.
5. At the point when fluid stops coming out, tighten the bleeder plug to 11 Nm (8 ft. lbs.), then release the brake pedal.
6. Repeat until all the air in the fluid has been bled out.
7. Repeat the procedure to bleed the air out of brake line for each wheel.
8. Check the fluid level and add DOT3 fluid if necessary.

Bleeding brakes in not difficult; however, it must be done correctly. The attached link is very discreptive and will walk you through everything needed (pictures are included).

http://www.popularmechanics.com/cars/how-to/maintenance/4213448

Please remember to rate my solution. Thanks!

bleeding the brakes -
look fo the bleeder ( zerk fitting ) on the side of the caliper, attach a 1/4 inch clear hose to this fitting and run hose into a catch pan or bottle,, make sure you have plenty of brake fluid in the reservoir ( re-fill as needed during the bleeding process ), have a helper sit in the car and ready to press down the brake pedal, with brake pedal up - open the zerk fitting using a small wrench, have the helper press down and hold the brake pedal to the floor, with the pedal down - close the zerk fitting, your helper can now release the pedal, ( repeat this about 3 to 4 times or until clean and bubble free fluid flows through the clear hose ) --- top off the reservoir with fluid and repeat these steps for the other brake calipers. Note: if brake pedal feels sloppy ( not firm ) then there is still air in one of the lines,, continue bleeding until pedal feels like it has some resistance.

c...

Bleeding brakes can be very frustrating.There are two ways you can do them 1 gravity feed;this means that you undo the bleeder screw on the caliper or the wheel cylinder and let the brake fluid flow until all air is removed from the system or 2 suction bleed; this involves going to your auto supply store and buying a small hand held pump that creates a suction which in turn,once connected over the bleeder screw,allows you to pull brake fluid and the air out of the system.If you have a friend to help you have them depress the brake pedal until it reaches the floor while you loosen the bleeder screw and discharge the air/fluid.Tighten the screw before the brake pedal is released,release the pedal and repeat.Keep checking the master cylinder and do not let the fluid run low.Don't pump the pedal repeatedly,brake fluid is hydroscopic,which means it can absorb air directly into itself.Slowly and firmly does it until you have purged all the air.You will know when it is all gone because hard pedal will come back.Good Luck

Here is the procedure from the service manual. I would add just one thing. Do each wheel in this order

1. right rear wheel
2. left rear wheel
3. right front wheel
4. left front wheel

BLEEDING

HINT: If any work is done on the brake system or if air in the brake lines is suspected, bleed the air from the system.

NOTICE: Do not let brake fluid remain on a painted surface. Wash it off immediately.


a)FILL BRAKE RESERVOIR WITH BRAKE FLUID Fluid:SAE J1703 or FMVSS No. 116 DOT3

b)BLEED MASTER CYLINDER HINT: If the master cylinder has been disassembled or if the reservoir becomes empty, bleed the air from the master cylinder.

c)Disconnect the brake lines from the master cylinder. SST 09023-00100 Slowly depress the brake pedal and hold it.

Block off the outlet plug with your finger and release the brake pedal.
Repeat (b) and (c) 3 or 4 times.


BLEED BRAKE LINE

1. Connect the vinyl tube to the caliper or wheel cylinder bleeder plug.
2. Depress the brake pedal several times, then loosen the bleeder plug with the pedal held down.
3. At the point when fluid stops coming out, tighten the bleeder plug, then release the brake pedal. Torque: (Bleeder plug) Front brake caliper
: 8.3 Nm (85 kgf-cm, 74 inch lbs.) Rear wheel cylinder: 8.5 Nm (87 kgf-cm, 75 inch lbs.)
4. Repeat (b) and (c) until all the air in the fluid has been bled out.
5. Repeat the above procedure to bleed the air out of the brake line for each wheel.

CHECK FLUID LEVEL IN RESERVOIR Check the fluid level and add fluid if necessary. Fluid: SAE J1703 or FMVSS No. 116 DOT3