Bleeding Brakes!!!

[IssacHunt]

Please help as I'm about to start self harming....

My son has a 2001 Triumph Daytona 955i. The front brake is very spongy and travel's back to the bar.

Pads are fairly new and calipers were stripped a few months ago for a clean up.

I've changed the fluid (although the fluid I had has been around for a while in the garage??) and bled them time after time, still spongy!!

I've bled them two ways, with pipe onto nipple into a jug and by pumping lever (with nipple closed) then releasing it with pressure applied. I've removed the nipple and put a tad of PTFE tape on them to make sure there not drawing air back in.

Could it be the fluid?

Any ideas before I pop out for a gallon of petrol and a box of swan vestas?

Many thanks.

 

[Beak Freak]

Was the Brake fluid from an unopened bottle? I always understood that once opened brake fluid did degrade (not sure if it oxidised or contaminated with moisture) and had always been told to use brand new fluid. I don't know if unopened brake fluid degenrates over time, but for the minimal cost it would seem certainly worth trying.

Also have you tried tying the brake lever back and leaving it overnight? something like a bungee or a tie wrap should be good. Just loosen the lid of the master cylinder so that any air in the system can escape.

I am very far from being an expert in this so if someone says I am talking a pile of steaming horsecr*p then please feel free to ignore the above.

 

[Sergeant Pluck]

Did the front brake ever work properly / not pull back to the bar? Reason I ask is that the front brake on Triumphs of that vintage are not great - the master cylinder does not have enough capacity to drive the caliper pistons and ( certainly on my '06 Tiger ), the lever will pull back to the bar without too much effort, air in system or not. By strange coincidence, I replaced the master cylinder on mine today for that very reason. The ( Nissin ) master cylinder and lever assembly from > '01 Kawasaki ZX6R, ZXR 636 etc are a direct fit right down to the lever and microswitch - and plentiful on eBay and from breakers etc. It's a twenty minute job to do the swap - after which you will need a Gorilla-like grip to get the lever anywhere near the bar!

Otherwise - does your bike have one hose wrapping over the mudguard from one caliper to the other ( as opposed to two long hoses direct to the calipers from the master cylinder )? If it does, it might be worth removing that caliper - hanging it vertically and bleeding it in that position. Air gets trapped at the top of the loop otherwise. And +1 to what the previous poster says - strapping the lever to the bar opens the little valve hole and will let air trapped in the cylinder filter slowly out.

Good luck.