Can't Get the Air Out of Those brakes!

[JohnnyMead]

I'm replacing the brake fluid on the TR3A and discovered bubbles, worse, a lot of bleeding later and I am still getting air. I've looked the whole system over for leaks and can't see any dampness anywhere, including the master cyl. Fluid level has been ok all summer. Could this be the master cyl?
Thanks for ideas, brake bleeding is usually easy on this car so something's going on.
John

 

[equiprx]

John,
Are you pumping up the system with slow constant stokes? Rapid pumps will induce cavitation.

 

[JohnnyMead]

Steve,
Good point, yes I'm trying to take everything slow. I'll focus on that when I try again.
John

 

[DNK]

What are you using as a liquid?

 

[JohnnyMead]

Hi Don,
I'm using Castrol LMA.
John

 

[DNK]

Thanks. Making sure it's not silli .
Bubbles with that are common

 

[tomgt6]

A trip a friend of mine told me about is to crack on of the bleeder a bit and leave it overnight. Then do the same thing to the others each night. He says it takes a while and some fluid but it normally gets rid of the bubbles.

 

[CJD]

How does the pedal feel?

I've had the bleed screw suck air if it is open to far while I bleed.

John

 

[JohnnyMead]

Thanks for all the suggestions! I've managed to get a lot of air out and the pedal is feeling firmer. I did a couple of things I don't usually try:
--left a bleeder nipple open over night
-- cracked the fitting at the rear rubber hose (got lot's of air out)
--didn't open the bleeders very far.
That rear hose is kind of a high spot and may be a good trap for air. My assistant said "wow what a difference" as soon as I bled once from that fitting.
Anyway, thanks again for all the comments!
John