Triumphrat

crazypierre

Hi,
Rear pistons in caliper are free (when I push one in, the other one comes out and vice versa.) However, when I press the brake pedal, they don't move out.
I took the bleed nipple off the rear caliper and nothing came out when I press the pedal. I took the brake pipe off the master cylinder and fluid drained out of the reservoir. Do you think the master cylinder is jammed up or could I have another problem?

Peter

crazypierre

Hi,
Rear pistons in caliper are free (when I push one in, the other one comes out and vice versa.) However, when I press the brake pedal, they don't move out.
I took the bleed nipple off the rear caliper and nothing came out when I press the pedal. I took the brake pipe off the master cylinder and fluid drained out of the reservoir. Do you think the master cylinder is jammed up or could I have another problem?

Peter

tridentt150v

Sorry, didn't see this post till now, hope I'm not too late.

It's your brake hose, the brake fliud affects them over time [unless you have a teflon ss braided one], and the inside of the hose softens and swells.

You can pump fluid through, cos it's under mechanical pressure, but the only thing returning the fluid is the return spring pushing the m/c cylinder back, this is a very soft action.

Take your brake hose off and {after washing it} try blowing through it, if you cannot do this, replace it.

__________________
tridentt150v,
Great Southern Land.
(Where women blow and men chunder).

crazypierre

Hi tridentt150v
I sorted the problem-you were (partly) right. It was a clogged rubber brake hose. The fluid in it had solidified over the years of non-use I guess. I managed to (eventually) push an old brake cable through it to unblock it and a load of black junk popped out. I then cleaned it out and put new fluid in and just bled it yesterday. Seems OK now.
So, luckily I did not buy a new master cylinder which I thought had seized up.
Thanks
Pete

Will

Be careful using a damaged or worn out brake line. The inner layers of rubber can come loose and function like a one way valve. You might have brakes that won't release, or brakes that won't work at all. That black gunk you pushed out of the line might be deteriorated rubber. New brake lines are a whole lot cheaper than crash repairs.

__________________
Will
It's a squid thing. You wouldn't understand.
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crazypierre

Will
Thanks for the advice. I did not think that the rubber might have deterioated as once the blockage had come out, it seemed to solve the problem. I will buy another pipe and change it over. Best to be safe than sorry I guess. Changing the pipe is not a problem but in order to bleed the brakes you need to remove the caliper and hold it upside down on these, which means removing the silencer and the rear wheel. (Another reason to buy some replacement pea-shooter silencers I guess.....)
Job for a wet weekend in London.
Peter

tridentt150v

As I said, and Will also stated, replace it.
The rubber will only soften and swell again. You haven't solved the problem, only postponed it.

__________________
tridentt150v,
Great Southern Land.
(Where women blow and men chunder).

tridentt150v

As I said, and Will also stated, replace it.
The rubber will only soften and swell again. You haven't solved the problem, only postponed it.

__________________
tridentt150v,
Great Southern Land.
(Where women blow and men chunder).