Question on brake bleeding...

[Yarflana]

I am familiar with brake bleeding, how to do it and such...my question is since I had to replace a rear, brake cylinder on a drum brake yesterday due to blowing it out, should I have to bleed the entire system?

I naturally bled that side (rear driver side), but I know the order is farthest to closest to the master cylinder.

I replaced the front pads, rotors, drums and shoes and I will say the brakes feel a bit squishy and not even as good as before I did the work. When I put on stainless lines and replaced the brake fluid a month ago, the feel was much better than it is now.

I think I need to bleed the entire system from furthest to closest again as it has to have air in the line somewhere.

Do you think? Any other thoughts?

[bronsin]

You should only have to bleed the wheel cylinder you replaced.

I would do it again and see if you find any air.

Perhaps though from the work you did previously there is air someplace.

You might try a total four wheel bleed.

If you get air....you found the problem

[Geoff Peace]

I am familiar with brake bleeding, how to do it and such...my question is since I had to replace a rear, brake cylinder on a drum brake yesterday due to blowing it out, should I have to bleed the entire system?

I naturally bled that side (rear driver side), but I know the order is farthest to closest to the master cylinder.

I replaced the front pads, rotors, drums and shoes and I will say the brakes feel a bit squishy and not even as good as before I did the work. When I put on stainless lines and replaced the brake fluid a month ago, the feel was much better than it is now.

I think I need to bleed the entire system from furthest to closest again as it has to have air in the line somewhere.


Do you think? Any other thoughts? It sounds as though you have air in the system. Normally you would only need to bleed the cylinder you have replaced, but you have done other work recently such as replacing brake lines and it all adds up. I would say bleed the whole system. Starting furthest away from the master cylinder and working toward it. How are you bleeding the brakes? Are you using a power system with an air supply? I always favour vacuum bleeding for cases such as this, slower, but more effective in extracting air.
Regards Geoff Peace.

[jcboy]

why are you bleeding it on the master cylinder end? the air inside the lines will still be there if ever. bleed it on the end of the line near the brake cylinder/wheel you serivced, do what 's called "pump-pump-pump-stay".

HTH.

[Geoff Peace]

why are you bleeding it on the master cylinder end? the air inside the lines will still be there if ever. bleed it on the end of the line near the brake cylinder/wheel you serivced, do what 's called "pump-pump-pump-stay".

HTH.This method was fine years ago. Do it on amodern car and the master cylinder piston will travel too far and the seals will be ruined. It has been known for the seals to be turned inside out by pump bleeding brakes. Either a pressure bleeder on the master cylinder, or vacuum at the wheels is the only safe way now.
Regards Geoff Peace.

[esse10]

You can still bleed them the old style as long as you know what you're doing and have good communications between yourself and the fellow doing the pedal pumping. The way you would move the master piston too far is if you keep pumping while the bleed valve is still partially opened, good communication and one pump and hold at a time works pretty good. Done that many times in all my cars, my 2 cents on this......

[Yarflana]

Ok ok...just getting back here on this.

I bled them just using the "gravity" method....slow and steady wins the race.

Firstly, I am not bleeding from the master, but from the wheel end of each line.

Secondly, I went back and started from furthest to shortest from MC and did a gravity bleed by just letting the fluid drip and watching for bubbles. I changed the fluid recently and noticed it is all nice and clear and has no bubbles at all. I also adjusted my e-brake a bit more so it has only one click to engage now.

Now...with the stainless lines from MI, new drilled and slotted rotors, Hawk pads, R1 shoes and drums, the brakes are firm and make braking the Yaris enjoyable again.

Thanks for all the help and suggestions.