Master Cylinder Installation

[bighealeysource]

Hey gang,
Well any of you who have viewed my recent posts know I've been having bloody brake issues. Have come to the conclusion to replace the
master cylinder in my BN2 as the one currently in the Healey is about 20 years old. So, know it is pretty straight forward on how to take off old one and install new one, but any advice, hints, etc will be appreciated so my 75 year old self lives to see 76 dealing with this!
Thanks,
Mike

 

[kodpkd]

What helped me the most is accessing the lower MC bolt into the firewall from under the car. Also don't tighten the firewall bolts until the brake lines are started. This allows you to wiggle the MC when trying to thread the brake line threads into the MC. Also tighten the lines, then loosen them, then do the final tightening.

 

[bighealeysource]

Hey kodpkd,
BN2's master cylinder is mounted to the frame rail on left side for left hand drive cars and right behind the inner wheel well so not
easy to access. Just accessing the brake line and reservoir line was a real pain but got them loosened and then taking the mounting
bolts off allowed just a bit more access so got everything off. Putting it back on required me loosening the reservoir mounting strap
so the entire assembly could be moved. Anyway, got 'er done, no leaks as far as I know but only from a gravity perspective, so
will be putting entire system under 15 pounds with my Motive Bleeder and keeping fingers crossed.
Regards,
Mike

 

[kodpkd]

When you are bleeding with the Motive try pushing the brake pedal full travel while the bleeder is open.

 

[bighealeysource]

Been bleeding the brakes this morning with the new master cylinder installed - and bench bled - and the Healey gods
must still be angry with me as not much of a pedal. Going to try what kodpkd suggested.

 

[kodpkd]

I assume you use a clear tube to monitor the fluid as you are bleeding. Also, while you are bleeding, spread the brake pads apart, this pushes the cylinders into the calipers, forcing air into the bleeder. Have you reverse bled the rear brakes. The BN2 original rear cylinders are backwards.
On your car, do your rears have two cylinders per wheel or one? It's the cars with two cylinders per wheel and a line connecting the two that should be reverse bled.

 

[bighealeysource]

I don't have front disc brakes as all BN2's are drums all around. Only have one wheel cylinder on the rear but two on front drums.
And the fronts have the small hard brake line connecting the two cylinders. So reverse bleed those - is that where you try to force
fluid up from the wheel cylinders back into the brake fluid reservoir ?

 

[kodpkd]

yes

 

[kodpkd]

With drums front and back,,,, the adjustment of the shoes is more important. I think from what I see the fronts are not adjustable.

 

[PHulst]

I don't have front disc brakes as all BN2's are drums all around. Only have one wheel cylinder on the rear but two on front drums.
And the fronts have the small hard brake line connecting the two cylinders. So reverse bleed those - is that where you try to force
fluid up from the wheel cylinders back into the brake fluid reservoir ?

You can use a large syringe like this:

https://www.amazon.com/gp/product/B00P90N3BY/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1