Anyone solved the "squishy" front brake problem?

Hello all,

I have an 08' Husky CR 125, and have recently replaced the rotor, pads and brake cable all in hopes of getting rid of the "squishy" feeling of the front brake (truth be told, I bent the rotor in a crash). I've bled the brakes several times and am at a loss. I talked to my mechanic and he said "back-bleeding" probably won't help -- but maybe getting a larger cylinder in the master cylinder might help. Talked to my Husky dealer and he offered to sell me a master cylinder rebuild kit but was honest that he's experienced the "squish" when the bike is sitting still ... but on the trail it seems to work ... I agreed with him that a rebuild may not fix the problem. I am, however, still envious of my friend's Japanese bikes and their solid front brakes. Any suggestions out there would be greatly appreciated.

I don't have what I would concider "squishy brakes" mine are predictable and strong.

I am sorry yours are not up to speed. Your mechanic said he didn't think back bleeding would work- that assumes its because there is absolutely positvely no air in the system. If that is absolutely known 100%- I don't know how to further help. But I suspect there is air in the system- either trapped from not getting it all out or your seals are allowing air.

I'd take the whole system off the bike as a whole, then bleed without any bend in the line- making the highest point the bleeder or the master cylinder depending on the type of bleeding you are doing (there are other threads on this). Once you are 100% there is no air in the system- now test- if if feels strong again, then you know what it should be like. If it gets spongy in a short time- I'd look at the seals in the master or the caliper and rebuild as needed. Then bleed the system really well again. At that point you should be in good shape.

I'm experiencing the same problem you are. I bought or I guess am in the process of buying a master cylinder rebuild kit but once I received it in the mail I had already figured out that it was not necessary. I did some research and swapped my buddies Nissin master cylinders onto mine and I still had the problem. The piston seals in the caliper tend to collect grime which makes them susceptible to allowing air in the system. Replace those and you should be good to go!

Hey lads this may or may not help but, has worked for me. Try pulling the brake leaver on hard and secure in the on position with a strap or cable tie etc etc. Leave over night.... The theory is the piston is left open allowing any small bubbles that may be in the system, to slowly travel up to the master cylinder. My front brake lever was definately firmer after this exercise. Give it a go, you have nothing to lose and its free.....

That does work, I have done that... my old ktm inspired me to try every trick in the book.

Also you can push the caliper closed with your knee with the bike on the kick stand and or a buddy holding it- or even throw it on its right hand side on the ground. By closing the caliper it pushes the fluid up to the master backwards and often gets those bubbles that are near the master to float to the reservoir . (can do this on the trail without a tool)

What Alvsey said has worked for us before as well.dan

Back bleed(reverse bleed) works for me. My 06 ktm xc 300 had a spongy feeling to until I back bled the heck out of it. My 09 husky also has Brembo brakes and it seems they are better but then again I back bleed them.

Using the caliper pistons to back bleed is what has worked the best for spongy brakes for me. Especially rear where the hose is so long with so many air trapping bends. Before pushing the pistons back, remove the rotor and pump the pistons almost all the way out. Watch so the reservoir doesn't go dry.
When pushing the pistons back, have the line as straight as possible with the master cylinder the highest. If you had to add fluid to get the pistons out, you will need to remove some as you back bleed to keep from making a mess.. If the brakes are still spongy and there is no sign of leaking at the caliper, the problem is most likely the master cylinder piston isn't sealing.