Front brakes losing pressure rapidly

[Jayneflakes]

Not sure if this will work for you, but get the brakes good and firm, then use a bungy rope to strap the brake lever on and leave it for a while. If you put a clean rag or piece of paper under the calipers, you will see if you have any fluid leaks. If the pressure drops in the system, the bungy will still keep pressure on the lever. This also encourages any air bubbles in the system to float to the higher point, usually the master cylinder reservoir.

When I did my brake lines a while back, we discovered that one banjo was leaking very slightly, so changed the olive and nipped them back up again. Problem sorted.

[yorkie_chris]

Originally Posted by Jayneflakes

This also encourages any air bubbles in the system to float to the higher point, usually the master cylinder reservoir.

Think about that...

[mackemforever]

Thanks for the suggestions. A member on here that is local has let me have some of the red rubber grease he had and I'm going to strip down my callipers and rebuild them properly this time. I thought I could get away without using any proper grease, just using clean brake fluid, last time but it sounds like that might be the problem.

[yorkie_chris]

I think brake fluid is worse than nothing. It turns to crystalline crap and makes things worse.

[mackemforever]

Well I stripped the callipers down again, rebuilt them properly this time with a bit of red rubber grease on the seals and it worked a treat.

Made me realise that the brakes haven't worked properly since I bought the bike 18 months ago, when I stopped at the bottom of my road I felt like I was going to go over the damn handlebars!

Thanks.