Working on a 1970 Nova and have completely restored the brake system which includes 4 wheel disk, new lines, Master cylinder, Disc combination valve and a summit 8" dual diaphragm booster.
I'm having allot of trouble bleeding the system, I have tried the suction method and reverse bleeding which still left me with an extremely spongy pedal ( almost to the floor ).
The Master Cylinder was Bench Bled before installation.
I'm pretty sure that I have watched almost every Brake Video that You Tube has to offer, so I'm hoping (and praying) for some of your wisdom !
Thanks,
Al
Try this it always works get a phoenix injector bleeding kit. Always works is it injects the fluid and pushes the air up
If you've tried everything else and still have air in the system, the Phoenix injector bleeding kit is a sure bet:
You could try the Phoenix bleeder as mentioned. If still spongy, might be internal leak in master cylinder. Can't remember which car show (I watch so many of them) but they went thru 2 new master cylinders before they got a good one. Just because it's new doesn't necessarily mean it's good.
Do what the motorcycle guys do and reverse bleed the system. Inject fluid at each caliper. If that doesn't fix it, I'd be checking your linkage and MC for defects.
Thanks for your opinions, Yes -I've tried (& own) the Phoenix V-5 reverse bleeder and still have an extremely spongy pedal (almost to the floor).
I've also used the "Vacuum pump" method as well.
I've been a bit curious if the "Reverse Bleeding" method, if it returns air to an already Bench Bled Master Cylinder ??
Question for Scotty: does the old GM proportioning valve complicate Bleeding (I have the special tool that you screw in), so is it possible to "Trap Air" in that "hunk of Brass" ???
This is the 2nd Master cylinder for this car, 1st one a re-built and the 2nd is new.
Also, you can test the MC by plugging the ports and then applying pedal pressure.
So, this is a head scratcher --even for a Pro. 🙂