6H bleeding brakes and still no luck

[gacksen]

it seems they just put them back and put pressure on the system. as they are now they are spot on. hopefully the weather will be nice

tmr and ill give it a go

[Zdisease]

Sort of on topic
1972 240Z - Rear Brakes bleed very slow
Stock drum brakes.

I bled the brakes yesterday due to air in the system (Car has been sitting for 6 years)
The rear brake bleed very slowly, brake pedal sinks to the floor slow as well.
 

Post bleeding the brake the pedal feel good.

Is this normal or am I experiencing a proportioning valve issue ?

[Pop's Z]

Sitting for that long, especially in Florida, undoubtedly you have moisture and possibly salt from the coastal air in the system. That leads to rust and crapola in the brake actuator cylinders, calipers, brake lines and bleed screws. If it were my car I would take the brake system apart and make sure that no rust or craploa remains. After 6 years I would replace the master cylinder, the rear cylinders(or at least a rebuild), and flush the lines thoroughly with acetone. I would also consider replacing the front calipers as they are probably deteriorated also. Unfortunately there is no easy, cheap or safe way to tackle the braking system. No brakes is a very dangerous, scary, and conceivably really expensive life-threatening proposition. There are no shortcuts when dealing with braking  systems. Good luck.

 

Cheers, Mike

[Zed Head]

, brake pedal sinks to the floor slow as well.

 

Post bleeding the brake the pedal feel good.

 

The pedal sinking to the floor is usually a sign of internal leakage in the master cylinder.  But your second comment is a little bit confusing.  If they feel good, what is the problem?

[Zdisease]

While bleeding the rear brakes the fluid stream was very weak (kind of a dribble). I am curious if this is a concern.

zdisease

[EuroDat]

Weak flow to the rear wheel cylinders sounds like rust and slim buildup in your system is the likely cause. The brake system has various small diameter holes that can get partially blocked specially after sitting for so long.

I agree with Pop's Z. The brakes are too important to take any short cuts. I would clean it out and replace anything and everything in doubt.

Chas

[grannyknot]

There is a  brass restrictor block in the rear brake line just in front of the spliter,  both of the ones I have opened up were full of years of crap. I would start there.

[Zdisease]

Thanks for the advice.

[Zdisease]

I removed the brass restrictor block.

Removed the 17 mm cap. soaked in gas for a few hours and blew it out.

Rear brakes now bleed well.

Question: While bleeding the rear brakes the brake pedal only went Half way to the floor. Is this a cause for concern?

72 240Z