roro 93
New Member
i will now tell you how to do a simple brake bleed on your car to remove the air from the system
resource: ED MAY automotive
before commencing the bleed, check the master cylinder reserviour and top up if necessary. The fluid must be maintained at a reasonable level during bleeding to ensure no air is drawn into the master cylinder.
*NOTE: you may need to top up the reserviour several times during bleeding*
Today i am explaining manual bleeding
1) attach a plastic tube or length of hose no longer then 40cm to the bleeder nipple on either the wheel cylinder or brake caliper, ensure it is a good fit over the nipple, the other end of the tube or hose should be placed into a bottle either a coke bottle or whatever you have, and it should be partially full, water will do or clean brake fluid (this ensure no air will be drawn back through the nipple)
2) unscrew the nipple 1/2(half) to 3/4( three quarters) of a turn to allow fluid to flow through the nipple
***MAJOR NOTE: if it is an old master cylinder, only pump the brake pedal as far as you would when normally braking, or damage to the seal and cups could result from travelling to a section the master cylinder hasn't seen for 10 or so years, then the pedal will sink to the floor and you will be up for a lot more then a bottle of brake fluid***
3) have an assistant slowly pump the brake pedal several times ensuring not to bring the pedal back up suddenly, this will pump the fluid through the system into the bottle, after a few pumps check the reserviour and remember how much the level drops for each set of pumps eg. 5 pumps at a time, if the hose is submerged the hose will bubble if any air is coming out, if no bubbles then there is no air in that particular section
4) when bubbles cease to appear and only fluid is being discharged from the hose you can then tighten (nip up) the bleeder nipple. Now before proceeding to the next wheel cylinder or brake caliper, check the reserviour fluid level and top up accordingly
** if unsure about the tubes sealing ability or the assistants workmanship, for added confidence you could nip up the bleeder nipple with each return stroke of the brake pedal, (when the brake pedal is released to its normal position)**
5) repeat the above steps for each caliper/cylinder
finish now that all 4 calipers/cylinders have been bled, pump the brake pedal a few times, it should feel firm and not squishy or spongy, if the pedal is squishy or spongy more bleeding may be required, if normal bleeding does not fix it then you may need to bleed the master cylinder. Now start the vehicle and feel the brake pedal it should feel somewhat firm but you shouldn't have to put much effort into it
Brake Booster Test
Now a simple test
1) ensure car is not running and key is off
2) pump brake pedal until nice and firm
3) hold pedal down as if you were braking hard (not epicly/stupidly hard)
4) start engine with foot still firm on brake pedal
5) if the vacuum booster is working correctly then the pedal should drop about 2-3 cm whilst applying pressure still, if not then you will have a hard time braking and should consider replacing the booster
resource: ED MAY automotive
before commencing the bleed, check the master cylinder reserviour and top up if necessary. The fluid must be maintained at a reasonable level during bleeding to ensure no air is drawn into the master cylinder.
*NOTE: you may need to top up the reserviour several times during bleeding*
Today i am explaining manual bleeding
1) attach a plastic tube or length of hose no longer then 40cm to the bleeder nipple on either the wheel cylinder or brake caliper, ensure it is a good fit over the nipple, the other end of the tube or hose should be placed into a bottle either a coke bottle or whatever you have, and it should be partially full, water will do or clean brake fluid (this ensure no air will be drawn back through the nipple)
2) unscrew the nipple 1/2(half) to 3/4( three quarters) of a turn to allow fluid to flow through the nipple
***MAJOR NOTE: if it is an old master cylinder, only pump the brake pedal as far as you would when normally braking, or damage to the seal and cups could result from travelling to a section the master cylinder hasn't seen for 10 or so years, then the pedal will sink to the floor and you will be up for a lot more then a bottle of brake fluid***
3) have an assistant slowly pump the brake pedal several times ensuring not to bring the pedal back up suddenly, this will pump the fluid through the system into the bottle, after a few pumps check the reserviour and remember how much the level drops for each set of pumps eg. 5 pumps at a time, if the hose is submerged the hose will bubble if any air is coming out, if no bubbles then there is no air in that particular section
4) when bubbles cease to appear and only fluid is being discharged from the hose you can then tighten (nip up) the bleeder nipple. Now before proceeding to the next wheel cylinder or brake caliper, check the reserviour fluid level and top up accordingly
** if unsure about the tubes sealing ability or the assistants workmanship, for added confidence you could nip up the bleeder nipple with each return stroke of the brake pedal, (when the brake pedal is released to its normal position)**
5) repeat the above steps for each caliper/cylinder
finish now that all 4 calipers/cylinders have been bled, pump the brake pedal a few times, it should feel firm and not squishy or spongy, if the pedal is squishy or spongy more bleeding may be required, if normal bleeding does not fix it then you may need to bleed the master cylinder. Now start the vehicle and feel the brake pedal it should feel somewhat firm but you shouldn't have to put much effort into it
Brake Booster Test
Now a simple test
1) ensure car is not running and key is off
2) pump brake pedal until nice and firm
3) hold pedal down as if you were braking hard (not epicly/stupidly hard)
4) start engine with foot still firm on brake pedal
5) if the vacuum booster is working correctly then the pedal should drop about 2-3 cm whilst applying pressure still, if not then you will have a hard time braking and should consider replacing the booster