|Posted on Sunday, December 26, 2021 - 11:36 am: ||
I have no rear brake pressure and I've bled some of it which there was no air bubbles. This area seems to be the culprit? My boyfriend had changed a sensor part a few months ago and hes not in the state to help. I really want to get this taken care of but, Im on my own with this
|Posted on Sunday, December 26, 2021 - 01:58 pm: ||
Does it feel like it is building any pressure or not? I've seen those master cylinders lock up. Have you tried bleeding it with a vacuum bleeder or pushing fluid in from the bottom? The master cylinder was about $30 new last time I needed to replace it.
|Posted on Monday, December 27, 2021 - 04:15 am: ||
A common problem is a weak master cylinder return spring. The piston must pass the transfer port which connects the reservoir to the cylinder in order to refill the cylinder on the return stroke. In order to remove this spring, the piston must come out. A good tip is to use compressed air and blow it out.
|Posted on Tuesday, December 28, 2021 - 02:37 am: ||
Have you verified that the caliper piston is not seized in its bore ? This does happen.
Remove the brake caliper, and push the piston back into its bore to verify its movement is good. Remove the pad first so you don't damage it.
Note, it will be somewhat hard to push back.
If the caliper is ok, it seems that the easiest thing to do is try to either find a used master cylinder THAT WORKS, or find a new one and just do the master cylinder swap.
This will be much easier than trying to diagnose an internal problem with little or no experience.
Just swap the master cylinder and bleed the system.
Be sure to "bench bleed" the cylinder before installing it. This makes it much easier for the final bleeding.
|Posted on Tuesday, December 28, 2021 - 07:15 pm: ||
i dont see a leak in the pic, but brake fluid is hydroscopic so it'll absorb into water instead of leaving a residue or oily sheen on top of a puddle. 1125 rear brakes have been known to fail, tho.
ive had good luck with forcing brake fluid in thru the caliper bleeder screw using a syringe. a second person with another syringe and the cap off the master cylinder and suck out the reservoir will keep it from puking brake fluid all over the place and watch for bubbles.