brake bleeding
-
tigermoth
- Posts: 15
- Joined: Sat Nov 07, 2015 4:53 pm
- Your interest in the forum: just become owner of a Javelin
- Given Name: robert
brake bleeding
i am new to Javelins and have a issue with brake bleeding and just wanted to check i am doing things right.having just changed a rear nearside wheel cylinder i am unable to get any fluid through the bleed nipple.the remote reservoir if full and the pedel goes to the floor does anyone have any idears.the brakes were fine before i started.thanks for your help.
-
Keith Clements
- websitedesign
- Posts: 3968
- Joined: Wed Feb 08, 2006 11:22 am
- Your interest in the forum: Jup NKD 258, the most widely travelled , raced and rallied Jowett.
- Given Name: Keith
- Contact:
Re: brake bleeding
As discussed yesterday on the phone-
These Indian/Chinese castings can be poor and have splits or blocks in the castings, so if you cannot get any fluid out with the nipple removed, disconnect the pipe where it enters the rear wheel cylinder and let fluid drip out, keeping the reservoir full. Very slowly depress the brake pedal and keep it depressed. Ideally have someone watch the pipe outlet to make sure fluid is coming out. Also ideally reconnect brake pipe to cylinder without releasing brake pedal so as not to suck air back into the system. If no fluid comes out after a couple of minutes you could try vigorously and repeatedly stamping the pedal. This might clear the air from the master cylinder.
The problem with bleeding the brakes by depressing the brake pedal is that it aerates the fluid meaning it may be a few days before it settles and you need to repeatedly bleed. I use a pressurised system that feeds fluid under pressure into the reservoir.
Take great care reconnecting the brake pipe as it is easy to cross thread the union. I have the cylinder loose to do this so that the thread has more chance of lining up.
Since your system may not have been attended to for many years it may have accumulated muck in the fluid. This muck may well start to scour the master cylinder rubbers and piston. Fluid left for a couple of years will contain water and this will rust all the pistons. Clean it all out and replace with Silicone. This will save the yearly ritual of 'doing the brakes'. And give you peace of mind!
These Indian/Chinese castings can be poor and have splits or blocks in the castings, so if you cannot get any fluid out with the nipple removed, disconnect the pipe where it enters the rear wheel cylinder and let fluid drip out, keeping the reservoir full. Very slowly depress the brake pedal and keep it depressed. Ideally have someone watch the pipe outlet to make sure fluid is coming out. Also ideally reconnect brake pipe to cylinder without releasing brake pedal so as not to suck air back into the system. If no fluid comes out after a couple of minutes you could try vigorously and repeatedly stamping the pedal. This might clear the air from the master cylinder.
The problem with bleeding the brakes by depressing the brake pedal is that it aerates the fluid meaning it may be a few days before it settles and you need to repeatedly bleed. I use a pressurised system that feeds fluid under pressure into the reservoir.
Take great care reconnecting the brake pipe as it is easy to cross thread the union. I have the cylinder loose to do this so that the thread has more chance of lining up.
Since your system may not have been attended to for many years it may have accumulated muck in the fluid. This muck may well start to scour the master cylinder rubbers and piston. Fluid left for a couple of years will contain water and this will rust all the pistons. Clean it all out and replace with Silicone. This will save the yearly ritual of 'doing the brakes'. And give you peace of mind!
skype = keithaclements ;
-
tigermoth
- Posts: 15
- Joined: Sat Nov 07, 2015 4:53 pm
- Your interest in the forum: just become owner of a Javelin
- Given Name: robert
Re: brake bleeding
brakes now sorted thanks keith for your help and advise. 