brakes losing prime

[banshee55615]

Was putting my new mod quad chain slider on so I pulled the rear swingarm off and took the two bolts off of the rear caliper and let it hang. When I put it all together and bled the rear brakes everything seemed fine but now after a day or two of sitting the rear brakes seem to go soft. No puddles under the wheeler when in garage no signs of a leak anywhere.

[banshee55615]

I have been using dot 3. every time i re bleed them they r great for the day and after it sits for a day or two they get soft again. i made sure the caliper was the highest point in the system when i bled them not really sure whats going on.

[FrankieSquid]

I hate brakes personally. I had to bleed mine two weeks back. But my brakes were the front. I used the ones specified i think it's dot 4 and 3. I used a synthetic dot 4 brake fluid. I don't know for the back if you need a brake bleeding tool but the one i bought worked flawless and took care of the brake bleeding in like 5 minutes, normally i was trying to gravity bleed them and many other useless methods took forever and it couldnt keep pressure for shit. On mine i had air bubbles in my master C. Im sure this info can be relevant to some extent i hope this helps.

[4strokekilla1987]

I hate brakes personally. I had to bleed mine two weeks back. But my brakes were the front. I used the ones specified i think it's dot 4 and 3. I used a synthetic dot 4 brake fluid. I don't know for the back if you need a brake bleeding tool but the one i bought worked flawless and took care of the brake bleeding in like 5 minutes, normally i was trying to gravity bleed them and many other useless methods took forever and it couldnt keep pressure for shit. On mine i had air bubbles in my master C. Im sure this info can be relevant to some extent i hope this helps.

 

 

lol i was bleeding mine yesturday both front and back i got the front done with no problem in like 10mins but the rear kicked my ass i gave up on it im gonna give it another try later on today

[4strokekilla1987]

wow when i did mine, it was the otherway around. i didn't have a pump at the time, but i could not get the front to get build up pressure, but i got the back done very quick.

 

 

i took a small clear tube put it on the fitting opened the fitting and sucked

[blowit]

Usually a loss of prime would indicate seal wear in the master cylinder as long as their are no visible signs of leakage. It is normal to see very tiny air bubbles in the master cylinder during cycling but they will form more or less foam at the top, not like an air bubble in the system.

 

It does not take much seal damage to cause problems with the brake system.

 

 

Brandon

[banshee55615]

I am going to look more into it tonight and try and figure out whats going on. Its just wierd that they worked fine before i took them off the swingarm and now need to be re bled all the time with no obvious signs of a leak. ha ha i hate brakes too! Stopping is overated.

[fastquad02blaster]

After they get soft, do they pump back up or do you have to rebleed them? Just wondering. I think its in your MC too.

[troyzstang]

One trick I learned was to use my garage vacuum. I take the crevice attachment and a small section of hose and simply insert one end of the hose in to the crevice tool. Wrap some duct tape around the outside of the end of the crevice tool to gain suction and then put the other end of the hose over the bleeder valve. Open the bleeder valve and turn on the vacuum. just make sure the resivour doesn't run dry. Kind of a hillbilly brake bleeder

 

Works everytime.

 

Good luck

[Judge1]

Buy a large syringe at the drug store and a foot of clear hose to connect to your fittings and you have a bleeder tool for five bucks. On the front master cylinder if you look closely the lid is not square and the words on top sould be readable sitting on the bike or you won't get a good seal.