TR2/3/3A bleeding brakes

Is there a secret to bleeding the brakes on TR 3. All new components and still can't get them to bleed. Started at the riders rear brake as normal but just get nothing. I must be missing something.

What brake fluid are you using? Silicone Dot 5 is quite difficult to bleed. It can hold tiny bubbles. Have to be very careful filling the reservoir to not get bubbles. Slowly pour it down a screwdriver shaft into the reservoir. I also recommend installing "speed bleeders". They make bleeding so much better and easier. I got mine for my TR250 and my TR3 from this guy Kirby. He can tell you the correct p/n to order for front, back, and clutch slave cylinder of your Triumph.

https://kirbysbrakebleeders.ecrater.com/

Bob

Did you bench bleed the new master? If not, you can do so in place by bleeding at the first fitting after the cylinder. This raises dangers to the paint if you are not using DOT5 fluid, so you might want to dismount the cyl and do the bench bleed. If the master is not moving fluid, you can't bleed the system. You can try just opening a couple of caliper/wheel cyl bleeders and let it sit, hoping that fluid will start to weep out. If it does, you will know that the barrel of the master has fluid in it. On technique at the wheels, you can have a pedal pumper in place, open a bleeder, call for one downstroke and hold on the pedal, close the bleeder, call for release of the pedal and repeat. Or, you can call for the pumper to pump a few strokes and hold, open the bleeder, close the bleeder, call for pedal release, and repeat. Or, you can fit a tight clear tube to the open bleeder, put the other end of the tube in a clear container of brake fluid and pump until you see bubbles begin and stop, then close the bleeder and remove the tube from the bleeder. Then there are low pressure air bleeders that attach to the opening of the master reservoir. Any of the above might work. I have never had to use an air bleeder and find that a reluctant system responds best, but slowly, to the first described technique. Just noticed the second post in this string. I have found that DOT5 behaves exactly as other compounds without the paint damage.

Happy mechanicing,

Bob

My friend had difficulty bleeding his brakes and puled out an old cap that he had mounted a air fitting on. He put that cap on the reservoir and used a bicycle hand pump . With a few short strokes it started working .

If the system was empty you have a long way to go, leaving bleeder open say rears with tube at bleeder to a bottle and pump peddle keep checking fluid level. Madflyer

I've had good results pulling the fluid through a clear tube, from the caliper, with a plastic syringe (Amazon). A good one-person method that doesn't involve negotiations with the 'Dreaded Assistant'.

I've had DOT5 in my Healey since 2017 and had a spongy pedal until recently evidently due to air in the fluid.

Re-bled mine as above in late 2020. The air had settled into a few large bubbles and was able to extract them with the syringe. I'd installed new bleeder screws wrapped in teflon tape - they still leak past the threads - the bubbles look like tiny Perrier fizz bubbles, compared to the large ones which were air in the lines. As soon as you're only looking at the tiny bubbles, Bob's your uncle for that cylinder. This gave me a hard pedal after 3 years.

DOT5, would suggest re-bleeding after some months until you get good results.

With regular fluid, bubbles will often float out quickly and you'll probably have a good pedal in a week or so.

I made this recirculating bleeder in order to 'bench' bleed a new MC installed dry in the car. Pipe attaches to MC output with clear tube into reservoir. Pump the pedal slowly to force the air out of the MC into the reservoir. Also shown is the syringe used for general bleeding.

New rod or old rod on the new MC

cityslicks said:

...Started at the riders rear brake as normal...

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Note the driver's side Rear is the farthest away from the MC.

Normally fluid will flow by just cracking one of the bleeders. +1 to you will need to bleed the master cylinder to remove the air.

Also, make sure the rod into the master is adjusted correctly so it fully relaxes. If it doesn't it can leave the port to the reservoir covered so fluid won't pump.

What John said, and I usually use some of that clear hose that fits snug on the zerk from the local hardware store place it into a bottle with some fluid, so I can see what comes out. Sometimes when the master cylinder is rebuilt and not new, they are difficult to bleed.

Thanks for all the help. I got it done .

cityslicks said:

Thanks for all the help. I got it done .

Click to expand...

What was the solution?

Always nice to have the resolution for future searches.