New Master Cylinder Problems

[BadlyBent]

First of all, I confess to rampant ignorance and malignant stupidity. That said, I need help.

I replace the old tired master cylinder in my 71 FJ40 with a new Aisin FJ80 master. It bolted up nicely. I thought I might have a relatively easy project but...

The master is pumping fluid to the front brakes (managed to spray myself proving it) but I can't get any fluid to the rears. The problems seems to be at the master - I leave the line off and pump the pedal but no fluid from the rear port. I suppose it could be a defective master but I suspect it's something I'm doing/ not doing.

Thoughts?

 

[snailwagon]

Did you bench bleed your MC before hooking up the brake lines?

 

[BadlyBent]

Here's where the rampant ignorance part comes in. No I didn't. Walk me through it if you could.

 

[BadlyBent]

I did search the posts on bench bleeding. I essentially did that by loosening the compressions fittings and pushing out the air/ brake fluid in the front. But again, no fluid to the rears. Any ideas?

 

[ohrly?]

try bench bleeding it again,

check ur brake lines for breaks

 

[Mendocino]

Here is a link that includes a video on bench bleeding. I added a FJ80 MS to my '75 '40 this evening.

How To Bleed Master Cylinder and Brake System

 

[BadlyBent]

Thanks for the advice (I can't believe there is a video of bench bleeding...). Will do and report progress.

 

[BadlyBent]

Mendocino and ohrly? Thanks for the advice. I'm wearing my sign. Bench bleeding did the trick. I now have outstanding stopping ability - made a HUGE difference switching to the 80 MC.