Bench bleeding single pot drum master cylinder

[Cianmini1]

I have a 65 Chrysler newport I’m replacing the master cylinder in.
4 wheel power drums
It’s only got 1 outlet in it and I’m bench bleeding it with a kit I got.
Since this is my first time doing this. Am I right in saying when I remove this tube and fitting and connect up my brake line, am I not going to introduce air into the master? If it has 2 fittings I could connect 1 by one.
I just want to be sure that I will have bled it properly and then bleed the brakes again.
Having no luck removing air out of the system so!
Thanks any help is really appreciated

 

[65Port]

Yes that's the way to do it. Bench bleed until no bubbles seen, install then bleed wheels. Bleed the passenger rear first, then driver rear finishing with driver's front (furthest to closest). You can try it without bleeding the wheels and see how the pedal is. I've done it both ways and prefer the extra step to be sure it's all out.

 

[Justin Plant]

Before removing the old one, set the parking brake. Install the new one. Release the brake, this should quickly force both fluid and air back through the system. Then bleed all corners for good measure. What you are going so far, is accurate. But the amount of air introduced is very small.

 

[Cianmini1]

Great thank you very muvh
Cheers

 

[CBODY67]

When changing a master cylinder, I did things a bit differently. Adapting how the brakes are bled at the assy plant.

When you remove the master cyl bleeding device, air CAN happen at that joint. What I did, several times on dual master cylinders, is to get the line fittings tight and verify the fluid level in the reservoir, THEN use several quick, short, fast pumps to put positive and negative pressure spiked into the fluid lines. On the negative pressure spikes, any air bubbles will expand and move upward into the reservoir. If a solid pedal does not result, repeat.

At the assy plant, before any brake fluid is put into the brake reservoir, a connector is attached to the open reservoir and a vacuum is pulled on the brake system. If the vacuum reaches a certain point and then holds there, then the brake fluid is inserted into the system. No wheel bleeding needed. Same with the coolant. These things are done near the end of the assy line and very close to the "Final Check" where the car goes through a four-roller chassis dyno road test and brake balance test.

The ONE good thing that wheel cyl brake bleeding does is flush the old fluid out and the new fluid in, for moisture removal issues. Of course, the master cyl brake fluid level MUST be monitored at all times during this process.

To me, if there is just a bubble ro two in the brake system at the master cyl, no need to force it further into the brake system when it can be eliminated at the top part of the system. I know that my way is not the classical way to do things, but it has worked well for me, several times.

Just my experiences,
CBODY67

 

[volksworld]

never really been a fan of bench bleeding as once you get it done yes air gets back in and now you're trying to install something that's dripping fluid all over...only advantage is you can get the master bled by yourself....iI prefer to install it dry,get a pan under it and bleed it at the lines first then go to the wheel cylinders, but that's just me

 

[Cianmini1]

Hi guys just an update,
Bled master cylinder, had to adjust the pushrod as it was too short on my new master! Bled all 4 wheels and brakes are now perfect! Thanks for all your help guys!

 

[edbods]

never really been a fan of bench bleeding as once you get it done yes air gets back in and now you're trying to install something that's dripping fluid all over...only advantage is you can get the master bled by yourself....iI prefer to install it dry,get a pan under it and bleed it at the lines first then go to the wheel cylinders, but that's just me

I've seen a few instances where the workshop manual insists on bench bleeding the master, but the master got installed dry and was then bled without any other issues. I did it on my old cressida like this and never had problems that way as well.