Disabling ABS is just removing a fuse.

When you bleed the brakes, address you fully flushing the system and topping up the brake fluid in the reservoir as you go? Any air that enters the system will result in spongy brakes.

You don't have a leak, or your pedal would just squash to the floor and brake fluid would be spitting out on the floor somewhere.

How are you bleeding the system?

 

IM using a vacuumpump bleed kit

 

I agree it sounds like air in the system, if you are not getting any air from any one of the calipers then there may be air trapped in the master cylinder, if you can bleed fluid from the master cylinder it may help.

 

Is often impossible to pump your "breaks" to flush air down and out the calipers. A suction is formed when the pedal lifts, sucking the air bubble right back up to where it was before you depressed the pedal.

Good professional mechanics will have a pressure bleeder which affixes to the reservoir cap. Provides a steady pressure and continuous supply of fresh brake fluid. Then all one has to do is go to each corner, open the bleeder until air stops and clean fluid flows. This is how they do it the first time at the factory.

Motive Products makes a tool you can buy. Or, instructions on the internet to make similar product out of a pump garden sprayer. The hard part is fabricating the fitting that goes over your reservoir.

Harbor Freight sells an air powered suction bleeder. Needs a pretty stout air compressor because it uses a lot of air. Provides steady suction at the bleeder so once the air bubble gets moving it doesn't have an opportunity to turn around and rise again. About $35 before sales events.

 

This is why I usually do it with two people.

One person pumps the brake while the other opens the bleeder valve on the caliper on the press, and then seals it off before the pedal is released. On, off, on, off until the line is completely flush and clear. Repeat for all corners, remembering to top up the reservoir as you go.

 

Ok then, is your new brake fluid a different colour to the original so you can see the old stuff getting pulled through completely?

 

yes. the old stuff looked like it had boiled after sitting for almost a year while I bought parts for the engine and did the repairs. it was dark brown/blackish .
I will bleed the master cylinder tomorrow.

 

If you "drained" the brake system you likely still have air trapped in the system.
Letting the lines, cylinders, calipers go empty is making more work.
It is usually sufficient to flush the system using tne new fluid to push the old fluid out.

 

"brakes"

is it not just a flexy firewall that makes the brake pedal feel spongey when you press it down?

 

here is how you can test the brake booster yourself.... note the sections on air tightness check, operation check, and loaded air tightness check.... also, the air tightness check will have you pump the brakes and the Expected result is that each successive brake stroke results in a higher pedal.... so depending on where the pedal is now, you might just be experiencing expected behavior.

some suggested things to check... pretty straightforward.

3. Excessive pedal stroke
(1) Entry of air into the hydraulic mechanism -- > Bleed the air.
(2) Excessive play in the master cylinder push rod --> Adjust.
(3) Fluid leakage from the hydraulic mechanism -- > Repair or replace (cup, piston seal, piston boot, master cylinder
piston kit, pipe or hose).
(4) Improperly adjusted shoe clearance --> Adjust.
(5) Improper lining contact or worn lining --> Correct or replace.

some pages on the brake booster attached.