I bought a cheap plastic oil can, the trigger variety, and half filled it with Dot4 Hyd fliud.
I spent most of the day trying to expel the air from my Honda front brake and left slamming the door to think about it.
I have never had problems in all my years that weren't cured by leaving it overnight.
No joy next morning, so, with air wanting to get to the top, why not fill from the bottom.

The tube on my bleed screw I pushed onto the oil can and cracked open the banjo at the top next to the brake cylinder. I squeezed the trigger until it leaked at the top then locked the bleed screw tight.
I then pulled the brake lever to expel the last bit of air and finally tightened the banjo. Bingo. Perfect.

This method can be applied to our K's. Put plenty of rag around the banjo so as not to damage the paintwork.

My method in future.
Ajays.

A good idea, and common to repair shops. We made a 'backwards' bleeder using forced air from the shop's air system and a discarded propane tank with a pressure gage fitted and nearly always bled brakes 'from the bottom' from then on.

Another thing I often do is to leave the cover loose or entirely off the master cylinder (with a clean rag over it) and secure a strong rubber band round the brake lever, which compresses the brake fluid a bit, then leave it like that overnight. Next day the lever almost always has a much firmer feel to it. Moving the 'bars round until the master cylinder sits in an ideal position to allow any latent air bubbles to escape can often result in a firmer feel as well.

Keep the good tips coming!

Well done Ajays.

Hi Guys,
I think the optimum solution for bleeding is a two pronged attack starting with a bike or car due for fluid replacement, first remove all old fluid in the master cylinder with a turkey baster (sneaked out of the kitchen then surreptitiously replaced after a trip through the dishwasher). Then force all the old fluid out the slave (brake calliper) cylinder into a jar.

That way no dirty or wet stuff goes back up into the lines leading back toward the master cylinder which I think is important particularly on any vehicle with ABS.

I think the point made about sucking or forcing the fluid into a dry system from the bottom is extremely smart because on a brake system car or bike the master cylinder is just about the highest point and what do bubbles do ? they rise, so is trying to expel air by pumping top down the best plan? I think not.

I know the Volvo car special tool for dealerships forces the fluid from the calliper up to the master cylinder and then out through a special master cylinder cap into the waste container.

One good tip when bleeding is to have wet cloths for wiping up and a bucket of water on hand in case of spills on the paintwork. When you hand pump the master cylinder at the handle bar be very careful not to let it come back too quickly or a squirt of fluid shoots out the top!
Regards,
K-BIKE

I am always bleeding my brakes by pushing the fluid from the bottom (caliper).
When I replace a caliper, I keep the pistons at their maximum extension, and pre-fill the caliper with fluid. When the caliper is back on the bike, I hookup the hose an spread the pistons apart in order to re-install the brake pads. This way, no air is trapped into the cylinder.

I was using an oil can like Ajays, but few year ago I switched to a big syringe (3/4" diameter - 5" long) and a piece of hose.
With the oil can, you have to close the bleed screw between each pumping action. With a syringe, you are pushing a continuous flow which makes the operation easier and faster.
The other advantage of the syringe is that you first chase any air bubble out of the fluid (check a nurse how she's tapping the side of the syringe) and you can see when it's time to refill it. Because of the constant pressure on the piston, the syringe is a container with a variable volume and no air enters it.
An oil can being a container with a fix volume, the fluid pushed to the caliper is replaced by air and you always have a slight chance to have both mixing together.

Bert

Pity it wasn't shared years ago.....would have solved many problems. I had never seen it on any forum before and there were plenty of queries about bleeding. Pardon me.
Ajays

Crazy Frog wrote:I am always bleeding my brakes by pushing the fluid from the bottom (caliper).
When I replace a caliper, I keep the pistons at their maximum extension, and pre-fill the caliper with fluid. When the caliper is back on the bike, I hookup the hose an spread the pistons apart in order to re-install the brake pads. This way, no air is trapped into the cylinder.

I was using an oil can like Ajays, but few year ago I switched to a big syringe (3/4" diameter - 5" long) and a piece of hose.
With the oil can, you have to close the bleed screw between each pumping action. With a syringe, you are pushing a continuous flow which makes the operation easier and faster.
Bert

Great idea Bert! The syringe you mention is probably from a farm supply house, a cow syringe kind of thing?
thanks,
Chris

87m6chris wrote:

Great idea Bert! The syringe you mention is probably from a farm supply house, a cow syringe kind of thing?
thanks,
Chris

Funny, I am just watching a program on the TV about a veterinary schools in Europe.

I've used a syringe designed for marinating. It is only good for one use, however. The brake fluid ate up the cheap plastic it was made out of. I suspect one from a farm store would hold up longer.