i did loose some brake fluid when changing the wheel cylinder. i can pump up the brake............ there is a small cap on the new wheel cylinder breather valve. should this be removed?
Forget any worries about the master cylinder, it will be fine.
From what you have said, the brake system needs bleeding.
What you are calling a breather valve is the bleed nipple on that wheel.
There will be a similar one on the other back wheel and one on each of the front wheels.
The plastic caps simply stop them getting dirty/clogged.
Air has got into the system. Hydraulic fluid is not compressible. Air is.
With NO air, the fluid acts as a solid object, transmitting force from the master cylinder to the cylinders on each wheel.
With air, a chunk of that force compresses the air, the result is more travel on the pedal. Extreme cases and you can run out of travel before the brakes bite.
They need bleeding.
You will need assistance from someone you trust to follow instructions or a powered bleed system.
May well be the time to go into any of the fast fit centres and ask them to do it.
Find a how to video on you tube to get a general idea then decide.
We'll advise if you want to do it yourself, first time I did my own brakes I think I made as many mistakes and we learn from them...hopefully before we kill ourselves.
If you could answer LD's questions would help us know if possible other errors.